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Back Interfacing of 28BYJ Stepper Driver with Arduino. What is so special about steppers? A stepper motor can move in accurate, fixed angle increments known as steps. For practical purposes, a stepper motor is a bit like a servo: you can tell it to move to a pre-defined position and can count on getting fairly consistent results with multiple repetitions. Servos though, are usually limited to a 0-180 degree range, while a stepper motor can rotate continuously, similar to a regular DC motor. The advantage of steppers over DC motors is that you can achieve much higher precision and control over the movement. The downside of using steppers is that they are a bit more complex to control than servos and DC motors . The 28BYJ-48 Stepper Motor Datasheet The 28BYJ-48 is a small, cheap, 5 volt geared stepping motors. These stepping motors are apparently widely used to control things like automated blinds, A/C units and are mass produced. Due to the gear reduction ratio of *approximately* 64:1 it offers decent torque for its size at speeds of about 15 rotations per minute (RPM). With some software “trickery” to accelerate gradually and a higher voltage power source (I tested them with 12 volts DC) I was able to get about 25+ RPM. These little steppers can be purchased together with a small breakout board for the Arduino compatible ULN2003 stepper motor driver for less than $5. Quite a bargain, compared to the price of a geared DC motor, a DC motor controller and a wheel encoder! The low cost and small size makes the 28BYJ-48 an ideal option for small robotic applications, and an excellent introduction to stepper motor control with Arduino. Here are the detailed specs of the 28BYJ-48 stepper motor. Motor Type Unipolar stepper motor Connection Type 5 Wire Connection (to the motor controller) Voltage 5-12 Volts DC Frequency 100 Hz Step mode Half-step mode recommended(8 step control signal sequence) Half-step mode: 8 step control signal sequence (recommended) 5.625 degrees per step / 64 steps per one revolution of the internal motor shaft Full Step mode: 4 step control signal Step angle sequence 11.25 degrees per step / 32 steps per one revolution of the internal motor shaft Manufacturer specifies 64:1 . Some patient and diligent people on the Arduino forums have disassembled the gear train of these little motors and determined that the exact gear ratio is in fact 63.68395:1 . My observations confirm their findings. These means that in the recommended half-step mode we will have:64 steps per motor rotation x 63.684 gear ratio = Gear ratio 4076 steps per full revolution (approximately). Wiring to the ULN2003 controller A (Blue), B (Pink), C (Yellow), D (Orange), E (Red, Mid- Point) Weight 30g Material Required: Material Quantity Arduino Uno 1 Stepper Driver 1 Jumper cables 6 Stepper Motor 1 Pinout Diagram: The motor has 4 coils of wire that are powered in a sequence to make the magnetic motor shaft spin. When using the full-step method, 2 of the 4 coils are powered at each step. The default stepper library that comes pre-installed with the Arduino IDE uses this method. The 28BYH-48 datasheet specifies that the preferred method for driving this stepper is using the half-step method, where we first power coil 1 only, then coil 1 and 2 together, then coil 2 only and so on…With 4 coils, this means 8 different signals, like in the table below. Circuit Diagram: Wiring the ULN2003 stepper motor driver to Arduino Uno : The ULN2003 stepper motor driver board allows you to easily control the 28BYJ-48 stepper motor from a microcontroller, like the Arduino Uno. One side of the board side has a 5 wire socket where the cable from the stepper motor hooks up and 4 LEDs to indicate which coil is currently powered. The motor cable only goes in one way, which always helps. On the side you have a motor on / off jumper (keep it on to enable power to the stepper). The two pins below the 4 resistors, is where you provide power to the stepper. Note that powering the stepper from the 5 V rail of the Arduino is not recommended. A separate 5-12 V 1 Amp power supply or battery pack should be used, as the motor may drain more current than the microcontroller can handle and could potentially damage it. In the middle of the board we have the ULN2003 chip. At the bottom are the 4 control inputs that should be connected to four Arduino digital pins . Hooking it up to the Arduino Connect the ULN2003 driver IN1, IN2, IN3 and IN4 to digital pin 3, 4, 5 and 6 respectively on the Arduino Uno. Connect the positive lead from a decent 5-12V battery pack to the “+” pin of the ULN2003 driver and the ground to the “-” pin. Make sure that the “on/off” jumper next to the “-” pin is on. If you power the Arduino from a different battery pack, connect the grounds together. Arduino stepper code and the AccelStepper library The default stepper library that comes pre-installed with the Arduino IDE supports the full-step method only and has limited features. It does not run the 28BYJ-48 motors very efficiently and getting two of them running at the same time for a differential drive robot is a bit more difficult. I came across example sketch by 4tronix that used the half-step method with no additional libraries. Their code worked well and I was able to modify it, so that I can run two steppers at the same time. Still, I was only able to get my stepper motor spinning fairly slow and it was getting quite warm, for some reason. Additionally, that sample code uses delays for the steps and that will cause some issues when we start adding more complex functions in the loop and hook up various sensors. Then I came across the AccelStepper library. It runs the 28BYJ-48 steppers very efficiently (they never go as hot as with the other options I tried) and also supports acceleration (which allows the stepper to get to a higher speed). The library uses non blocking code for the steps and has quite a few other nice features. After some messing around with the documentation and the examples I got everything up and running. Below is the code that will slowly accelerate the 28BYJ-48 in one direction, then decelerate to a stop and accelerate in the opposite direction. Naturally, make sure you download and install the AccelStepper library first! #include #define HALFSTEP 8 // Motor pin definitions #define motorPin1 3 // IN1 on the ULN2003 driver 1 #define motorPin2 4 // IN2 on the ULN2003 driver 1 #define motorPin3 5 // IN3 on the ULN2003 driver 1 #define motorPin4 6 // IN4 on the ULN2003 driver 1 // Initialize with pin sequence IN1-IN3-IN2-IN4 for using the AccelStepper with 28BYJ-48 AccelStepper stepper1 ( HALFSTEP , motorPin1 , motorPin3 , motorPin2 , motorPin4 ); void setup () { stepper1 . setMaxSpeed ( 1000.0 ); stepper1 . setAcceleration ( 100.0 ); stepper1 . setSpeed ( 200 ); stepper1 . moveTo ( 20000 ); } //--(end setup )--- void loop () { //Change direction when the stepper reaches the target position if ( stepper1 . distanceToGo () == 0 ) { stepper1 . moveTo (- stepper1 . currentPosition ()); } stepper1 . run (); } The code above will not push this motor to its limit. You can experiment with the acceleration and speed settings to see what is the best you can squeeze out. Note that for nigher speeds, you will likely need a higher voltage DC source. If you got your stepper running, here is the code that the StepperBot from the video above is running. You will need to adjust the speed, as well variables based on your base and wheel sizes, if you want to have your bot moving in a square path. #include #define HALFSTEP 8 // motor pins #define motorPin1 3 // IN1 on the ULN2003 driver 1 #define motorPin2 4 // IN2 on the ULN2003 driver 1 #define motorPin3 5 // IN3 on the ULN2003 driver 1 #define motorPin4 6 // IN4 on the ULN2003 driver 1 #define motorPin5 8 // IN1 on the ULN2003 driver 2 #define motorPin6 9 // IN2 on the ULN2003 driver 2 #define motorPin7 10 // IN3 on the ULN2003 driver 2 #define motorPin8 11 // IN4 on the ULN2003 driver 2 // Initialize with pin sequence IN1-IN3-IN2-IN4 for using the AccelStepper with 28BYJ-48 AccelStepper stepper1 ( HALFSTEP , motorPin1 , motorPin3 , motorPin2 , motorPin4 ); AccelStepper stepper2 ( HALFSTEP , motorPin5 , motorPin7 , motorPin6 , motorPin8 ); // variables int turnSteps = 2100 ; // number of steps for a 90 degree turn int lineSteps = - 6600 ; //number of steps to drive straight int stepperSpeed = 1000 ; //speed of the stepper (steps per second) int steps1 = 0 ; // keep track of the step count for motor 1 int steps2 = 0 ; // keep track of the step count for motor 2 boolean turn1 = false ; //keep track if we are turning or going straight next boolean turn2 = false ; //keep track if we are turning or going straight next void setup () { delay ( 3000 ); //sime time to put the robot down after swithing it on stepper1 . setMaxSpeed ( 2000.0 ); stepper1 . move ( 1 ); // I found this necessary stepper1 . setSpeed ( stepperSpeed ); stepper2 . setMaxSpeed ( 2000.0 ); stepper2 . move (- 1 ); // I found this necessary stepper2 . setSpeed ( stepperSpeed ); } void loop () { if ( steps1 == 0 ) { int target = 0 ; if ( turn1 == true ) { target = turnSteps ; } else { target = lineSteps ; } stepper1 . move ( target ); stepper1 . setSpeed ( stepperSpeed ); turn1 = ! turn1 ; } if ( steps2 == 0 ) { int target = 0 ; if ( turn2 == true ) { target = turnSteps ; } else { target = - lineSteps ; } stepper2 . move ( target ); stepper2 . setSpeed ( stepperSpeed ); turn2 = ! turn2 ; } steps1 = stepper1 . distanceToGo (); steps2 = stepper2 . distanceToGo (); stepper1 . runSpeedToPosition (); stepper2 . runSpeedToPosition (); } Tested Programming Code: #define IN1 3 #define IN2 4 #define IN3 5 #define IN4 6 int Steps = 4096; //4096 or 768 int cstep = 0; void setup() { Serial.begin(9600); pinMode(IN1, OUTPUT); pinMode(IN2, OUTPUT); pinMode(IN3, OUTPUT); pinMode(IN4, OUTPUT); } void loop() { for(int x=0;x

Back Measuring Humidity and temperature using DHT11 sensor with Arduino. What is a Digital Humidity Temperature Sensor? DHT11 is a Humidity and Temperature Sensor, which generates calibrated digital output. DHT11 can be interface with any microcontroller like Arduino, Raspberry Pi, etc. and get instantaneous results. DHT11 is a low-cost humidity and temperature sensor which provides high reliability and long-term stability. Material Required: Material Quantity Arduino Uno 1 DHT11 Sensor 1 Jumper cables 3 Pinout Diagram: Working: Ok now let’s see how these sensors work. They consist of a humidity sensing component, an NTC temperature sensor (or thermistor) and an IC on the back side of the sensor. For measuring humidity they use the humidity sensing component which has two electrodes with moisture holding substrate between them. So as the humidity changes, the conductivity of the substrate changes or the resistance between these electrodes changes. This change in resistance is measured and processed by the IC which makes it ready to be read by a microcontroller. On the other hand, for measuring temperature these sensors use an NTC temperature sensor or a thermistor. A thermistor is a variable resistor that changes its resistance with the temperature change. These sensors are made by sintering semiconductive materials such as ceramics or polymers to provide larger changes in the resistance with just small temperature changes. The term “NTC” means “Negative Temperature Coefficient”, which means that the resistance decreases with an increase in the temperature. Circuit Diagram: The DHTxx sensors have four pins, VCC, GND, data pin and a not connected pin which has no usage. A pull-up resistor from 5K to 10K Ohms is required to keep the data line high and to enable the communication between the sensor and the Arduino Board. There are some versions of these sensors that come with a breakout board with a built-in pull-up resistor and they have just 3 pins. The DHTXX sensors have their single wire protocol used for transferring the data. This protocol requires precise timing and the timing diagrams for getting the data from the sensors can be found in the datasheets of the sensors. However, we don’t have to worry much about these timing diagrams because we will use the DHT library which takes care of everything. Tested Programming Code: First, we need to include the DHT library which can be found from the Arduino official website or can be downloaded from the following link https://github.com/adidax/dht11 then define the PIN to which our sensor is connected and create a DHT object. In the setup section, we need to initiate the serial communication because we will use the serial monitor to print the results. Using the read22() function we will read the data from the sensor and put the values of the temperature and the humidity into the t and h variables. If you use the DHT11 sensor you will need to you the read11() function. In the end, we will print the temperature and the humidity values on the serial monitor. #include "DHT.h" #define DHTPIN 2 DHT dht(DHTPIN, DHTTYPE); void setup() { Serial.begin(9600); Serial.println("DHTxx test!"); dht.begin(); } void loop() { measurements. delay(2000); float h = dht.readHumidity(); float t = dht.readTemperature(); float f =dht.readTemperature(true); if (isnan(h) || isnan(t) || isnan(f)) { Serial.println("Failed to read from DHT sensor!"); return; } float hi = dht.computeHeatIndex(f, h); Serial.print("Humidity: "); Serial.print(h); Serial.print(" %\t"); Serial.print("Temperature: "); Serial.print(t); Serial.print(" *C "); Serial.print(f); Serial.print(" *F\t"); Serial.print("Heat index: "); Serial.print(hi); Serial.println(" *F"); } After we will upload this code to the Arduino board, the temperature and humidity results from the sensor can be seen on the Serial monitor. Precautions: Double-check the connections before powering on the circuit. Don’t use loose jumper cables. Check whether the proper board is selected from Arduino IDE. Ensure proper placement of sensor for correct working. Don’t put the sensor in any fluid or water, this is meant for taking ambient readings only. Conclusion: You can successfully measure temperature and humidity using the DHT11 sensor. Many more other applications can be made and triggered using the DHT11 sensor. Output: Situation Screenshot: Serial Monitor (Ctrl+Shift+M) Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of Metal Touch Sensor with Arduino. What is a Metal Touch Sensor? A metal touch sensor is a type of switch that only operates when it's touched by a charged body. It has a high-frequency transistor which can conduct electricity when receiving electromagnetic signals. The sensor has 3 main components on its circuit board. First, the sensor unit at the front of the module which measures the area physically and sends an analog signal to the second unit, the amplifier. The amplifier amplifies the signal, according to the resistant value of the potentiometer, and sends the signal to the analog output of the module. The third component is a comparator which switches the digital out and the LED if the signal falls under a specific value. In this experiment, touch the base electrode of a transistor with fingers to make it conduct electricity, for human body itself is a kind of conductor and an antenna that can receive electromagnetic waves in the air. These electromagnetic wave signals collected by human body are amplified by the transistor and processed by the comparator on the module to output steady signals. You can control the sensitivity by adjusting the potentiometer. Please notice: The signal will be inverted; that means that if you measure a high value, it is shown as a low voltage value at the analog output. Technical data / Short description Outputs a signal if the metal pike of the Sensor was touched. You can adjust the sensitivity of the sensor with the controller. Digital Out: At the moment of contact detection, a signal will be outputted. Analog Out: Direct measuring value of the sensor unit. LED1: Shows that the sensor is supplied with voltage LED2: Shows that the sensor detects a magnetic field Material Required: Material Quantity Arduino Uno 1 Metal Touch Sensor 1 Jumper cables 4 Pinout Diagram: This sensor doesn't show absolute values (like exact temperature in °C or magnetic field strength in mT). It is a relative measurement: you define an extreme value to a given normal environment situation and a signal will be send if the measurement exceeds the extreme value. Tested Programming Code: // Declaration and initialization of the input pin int Analog_Eingang = A0; int Digital_Eingang = 3; void setup () { pinMode (Analog_Eingang, INPUT); pinMode (Digital_Eingang, INPUT); Serial.begin (9600); } // The program reads the current value of the input pins // and outputs it via serial out void loop () { float Analog; int Digital; // Current value will be read and converted to the voltage Analog = analogRead (Analog_Eingang) * (5.0 / 1023.0); Digital = digitalRead (Digital_Eingang); // and outputted here Serial.print ("Analog voltage value:"); Serial.print (Analog, 4); Serial.print ("V, "); Serial.print ("Extreme value:"); if(Digital==1) { Serial.println (" reached"); } Else { Serial.println (" not reached yet"); } Serial.println ("----------------------------------------------------------------"); delay (200); } Precautions: 1. Double check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether proper board is selected from Arduino IDE. 4. Ensure proper placement of sensor for correct working. 5. Don’t lose hope if Sensor does not run properly for the first time, try again. Conclusion: You can successfully interface metal touch sensor and check for different conductivity values and can use it to detect different bodies when they come in contact. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of Temperature Sensor (LM35) with Arduino Uno. What is a Temperature Sensor? LM35 is a precision temperature sensor with its output proportional to the temperature (in C). With LM35, temperature can be measured more accurately than with a thermistor. It also possess low self heating and does not cause more than 0.1 C temperature rise in still air. The operating temperature range is from -55°C to 150°C. The output voltage varies by 10mV in response to ambient temperature; its scale factor is 0.01V/ C. Material Required: Material Quantity Arduino Uno 1 Temperature Sensor(LM35) 1 Jumper cables 4 Pinout Diagram: Circuit Diagram: Parameter Value VCC 5 V DC from your Arduino Ground GND from your Arduino Out Connect to Analog Pin A0 Tested Programming Code: float tempC; int reading; int tempPin = 0; void setup() { analogReference(INTERNAL); Serial.begin(9600); } void loop() { reading = analogRead(tempPin); tempC = reading / 9.31; Serial.print("Temprature= "); Serial.print(tempC); Serial.print("*C"); Serial.println(); delay(1000); } Precautions: 1. Double check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether proper board is selected from Arduino IDE. 4. Ensure proper placement of Temperature Sensor for correct working. 5. Don’t lose hope if Temperature Sensor does not run properly for the first time, try again. Conclusion: Once your sketch is running, you have to open your serial monitor. There you can see the Temperature of the surroundings. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of LDR Sensor Module with Arduino Uno. What is a LDR Sensor Module ? LDR sensor module is used to detect the intensity of light. It is associated with both analog output pin and digital output pin labelled as AO and DO respectively on the board. When there is light, the resistance of LDR will become low according to the intensity of light. The greater the intensity of light, the lower the resistance of LDR. The sensor has a potentiometer knob that can be adjusted to change the sensitivity of LDR towards light. Material Required: Material Quantity Arduino Uno 1 LDR Sensor Module 1 Jumper cables 4 Pinout Diagram: Circuit Diagram: Parameter Value VCC 5 V DC from your Arduino Ground GND from your Arduino A0 Connect to Analog Pin A0 Tested Programming Code: int sensorPin = A0; // select the input pin for LDR int sensorValue = 0; // variable to store the value coming from the sensor void setup() { Serial.begin(9600); //sets serial port for communication } void loop() { sensorValue = analogRead(sensorPin); // read the value from the sensor Serial.println(sensorValue); //prints the values coming from the sensor on the screen delay(100); } Precautions: 1. Double check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether proper board is selected from Arduino IDE. 4. Ensure proper placement of LDR Sensor Module for correct working. 5. Don’t lose hope if LDR Sensor Module does not run properly for the first time, try again. Conclusion: Once your sketch is running, you have to open your serial monitor to check the readings. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of Buzzer with Arduino Uno. What is a Buzzer? Buzzers are used for making beep alarms and tones. They can be used in alarm systems, for keypad feedback, or some games. Lightweight, simple construction and low price make it usable in various applications like car/truck reversing indicators, computers, call bells etc. Material Required: Material Quantity Arduino Uno 1 Buzzer 1 Jumper cables 5 Resistor 1(100 ohms) Pinout Diagram: Circuit Diagram: The Connections are pretty simple: Connect the Supply wire (RED) of the buzzer to the Digital Pin 9 of the Arduino through a 100-ohm resistor. Connect the Ground wire (BLACK) of the buzzer to any Ground Pin on the Arduino. Tested Programming Code: This code is to generate an alarm type of sound. The tone is an Arduino Library to produce a square wave of the specified frequency (and 50% duty cycle) on any Arduino pin. const int buzzerPin = 9; void setup() { Serial.begin(8600); pinMode(buzzerPin, OUTPUT); void loop() { tone(buzzerPin, 50); delay(50); noTone(buzzerPin); delay(100); } } Precautions: 1. Double-check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether the proper board is selected from Arduino IDE. 4. Ensure proper placement of Buzzer for correct working. 5. Don’t lose hope if Buzzer does not run properly for the first time, try again. Conclusion: You can Use Buzzer as an Alarm and many Other Alerting Devices . Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Analog Joystick Interfacing with Arduino UNO. What is an Analog Joystick ? Analog joystick produces two voltages; one corresponding to position with respect to X-axis and another corresponding to the position with respect to Y-axis. The voltages produced depend on the position of the joystick. The Analog Joystick is similar to two potentiometers connected together, one for the vertical movement (Y-axis) and other for the horizontal movement (X-axis). The joystick also comes with a Select switch . It can be very handy for retro gaming, robot control or RC cars. Material Required: Material Quantity Arduino Uno 1 Analog Joystick 1 Jumper cables 5 Pinout Diagram: We need 5 connections to the joystick. The connection are : SW( Switch), Y, X, Voltage and Ground. “Y and X” are Analog and “Switch” is Digital. If you don’t need the switch then you can use only 4 pins. Circuit Diagram: This is circuit diagram of Analog Joystick module in Arduino. There five pins in analog Joystick Module VCC, GND, SW, X, and Y. X and Y are Analog pins and SW is digital. Key will be used when Joystick is pressed. Connect VCC of the module to +5v of Arduino and GND of the module to Arduino Ground. Now, connect X to Analog pin A0 and Y to Analog pin A1 of Arduino.. Tested Programming Code: This is code for interfacing analog Joystick Module in Arduino. First initialized the pin numbers of Joystick Module. In setup, the Serial Monitor is started at 9600 Baud and initialized Joystick pins as input. In the loop, read the button state and stored in a variable. Print the values to the Serial Monitor. const int joystick_x_pin = A2; const int joystick_y_pin = A1; void setup() { Serial.begin(9600); /* Define baud rate for serial communication */ } void loop() { int x_adc_val, y_adc_val; float x_volt, y_volt; x_adc_val = analogRead(joystick_x_pin); y_adc_val = analogRead(joystick_y_pin); x_volt = ( ( x_adc_val * 5.0 ) / 1023 ); /*Convert digital value to voltage */ y_volt = ( ( y_adc_val * 5.0 ) / 1023 ); /*Convert digital value to voltage */ Serial.print("X_Voltage = "); Serial.print(x_volt); Serial.print("\t"); Serial.print("Y_Voltage = "); Serial.println(y_volt); delay(100); } Checking Values on Serial Monitor: After Uploading The program Successfully into the Arduino Board , we Can Check the Values of X and Y Serial Monitor The Image of the Serial monitor Is shown Below : Precautions: 1. Double check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether proper board is selected from Arduino IDE. 4. Ensure proper placement of sensor for correct working. 5. Connect the Wiper pin of potentiometer correctly. 6. Don’t lose hope if Joystick does not runs properly for the first time, try again. Conclusion: You can successfully display data on a the Serial Monitor of the Joystick in simplest way using Arduino. Many forms of data can be displayed on this display, whether it can be a data from sensor or anything else. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Measuring soil moisture using Soil Moisture Sensor with Arduino (Y-38) What is a Soil Moisture Sensor? This sensor measures the volumetric content of water inside the soil and gives us the moisture level as output. The sensor is equipped with both analog and digital output, so it can be used in both analog and digital mode. So let’s begin our tutorial on interfacing Arduino and Soil moisture sensor. Specifications: Input Voltage : 3.3– 5V Output Voltage : 4.2V Input Current : 35mA Output Signal : Both Analog and Digital Material Required: Material Quantity Arduino Uno 1 Soil Moisture Sensor 1 Jumper cables 5 Pinout Diagram: The soil Moisture sensor YL-38has four pins VCC: For power A0: Analog output D0: Digital output GND: Ground The Module also contains a potentiometer which will set the threshold value and then this threshold value will be compared by the LM393 comparator. The output LED will light up and down according to this threshold value. Working: The soil moisture sensor consists of two probes which are used to measure the volumetric content of water. The two probes allow the current to pass through the soil and then it gets the resistance value to measure the moisture value. When there is more water, the soil will conduct more electricity which means that there will be less resistance. Therefore, the moisture level will be higher. Dry soil conducts electricity poorly, so when there will be less water, then the soil will conduct less electricity which means that there will be more resistance. Therefore, the moisture level will be lower. This sensor can be connected in two modes; Analog mode and digital mode. First, we will connect it in Analog mode, and then we will use it in Digital mode. Analog Mode – Interfacing Soil Moisture Sensor and Arduino' To connect the sensor in the analog mode, we will need to use the analog output of the sensor. When taking the analog output from the soil moisture sensor FC-28, the sensor gives us the value from 0-1023. The moisture is measured in percentage, so we will map these values from 0 -to 100, and then we will show these values on the serial monitor. You can further set different ranges of the moisture values and turn on or off the water pump according to it. Circuit Diagram: The connections for connecting the soil moisture sensoYL-38 to the Arduino are as follows. VCC of YL-38 to 5V of Arduino GND of YL-38 to GND of Arduino A0 of YL-38 to A0 of Arduino Tested Programming Code: const int soil_sensor = A0; sensor is attached to int sensorValue = 0; void setup() { Serial.begin(9600); } void loop() { sensorValue = analogRead(soil_sensor); serial monitor: Serial.print("Moisture Value = " ); Serial.println(sensorValue); delay(1000); } Digital Mode – Interfacing Arduino and Soil Moisture Sensor To connect the soil moisture sensor YL-38 in the digital mode, we will connect the digital output of the sensor to the digital pin of the Arduino. The Sensor module contains a potentiometer with it, which is used to set the threshold value. This threshold value is then compared with the sensor output value using the LM393 comparator which is placed on the sensor module. The LM393 comparator will compare the sensor output value and the threshold value and then gives us the output through the digital pin. When the sensor value will be greater than the threshold value, then the digital pin will give us 5V and the LED on the sensor will light up and when the sensor value will be less than this threshold value, then the digital pin will give us 0V and the light will go down. Circuit Diagram: The connections for connecting the soil moisture sensor YL-38 to the Arduino in digital mode are as follows. · VCC of YL-38 to 5V of Arduino · GND of YL-38 to GND of Arduino · D0 of YL-38 to pin 12 of Arduino · LED positive to pin 13 of Arduino · LED negative to GND of Arduino Tested Programming Code int led_pin =13; int sensor_pin =8; void setup() { pinMode(led_pin, OUTPUT); pinMode(sensor_pin, INPUT); } void loop() { if(digitalRead(sensor_pin) == HIGH) { digitalWrite(led_pin, HIGH); } else { digitalWrite(led_pin, LOW); delay(1000); } } Precautions: 1. Double check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether the proper board is selected from Arduino IDE. 4. Ensure proper placement of sensor for correct working. 5. Please keep your hardware away from water except, the sensing probe. Conclusion: You can successfully measure the moisture percentage in the soil and control the appropriate flow of water. This sensor can be deployed in many ways like auto irrigation systems, automatic plant watering systems etc. Output: Situation Screenshot: Serial Monitor (Ctrl+Shift+M) Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Finding an obstacle using IR Sensor with Arduino What is an Infrared Sensor? An infrared sensor is an electronic instrument which is used to sense certain characteristics of its surroundings by either emitting and/or detecting infrared radiation. Infrared sensors are also capable of measuring the heat being emitted by an object and detecting motion. Material Required: Material Quantity Arduino Uno 1 Infrared Sensor 1 Jumper cables 5 LED Bulb 1 Pinout Diagram: Circuit Diagram: Working: This is a multipurpose infrared sensor which can be used for color detection. The sensor provides a digital as output. An on board LED is used to indicate the presence of an object. This digital output can be directly connected to an Arduino, Raspberry Pi or any other microcontroller to read the sensor output.IR sensors are highly susceptible to ambient light and the IR sensor on this sensor is suitably covered to reduce effect of ambient light on the sensor. The on board potentiometer should be used to calibrate the sensor. An infrared light emitting diode (IR LED) emits light of Infrared range 700 nanometers (nm) to 1 mm. This light is not visible by naked eyes but can be seen by a camera (that is why these are also used in night vision cameras). A photo diode gives response in term of change in resistance when light falls on it. That change is measured in terms of voltage. An IR LED and a Photo diode are used in a combination for proximity and color detection. An IR LED (transmitter) emits IR light, that light gets reflected by the object, the reflected light is received by an IR receiver (Photo Diode). Amount of reflection and reception varies with the distance. This difference causes to change in input voltage through IR input. This variation in input voltage is used for proximity detection. For color detection application: The amount of reflected light depends upon the color of surface from which it is reflected. The reflection is different for different colored surfaces. This makes it a color detector. Tested Programming Code: int LED = 13; // Use the onboard Uno LED int obstaclePin = 2; // This is our input pin int hasObstacle = LOW; // LOW MEANS NO OBSTACLE void setup() { pinMode(LED, OUTPUT); pinMode(obstaclePin, INPUT); Serial.begin(9600); } void loop() { hasObstacle = digitalRead(obstaclePin); //Reads the output of the obstacle sensor from the 7th PIN of the Digital section of the arduino if (hasObstacle == LOW) //LOW means path is clear, so red light connected to 13th Port connected LED is off. { Serial.println("Path is Clear"); digitalWrite(LED, LOW);//Illuminates the 13th Port LED } else { Serial.println("Stop something is ahead!!"); digitalWrite(LED, HIGH); } delay(200); } Precautions: 1. Double Check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check Whether proper board is selected from Arduino IDE. 4. Ensure proper placement of sensor for correct working. Conclusion: You can successfully check for an obstacle using an IR sensor. Many more other applications can be made using Infrared sensor as it has many possibilities to work with. Output: Place the object in front of IR proximity sensor and observe the change in LED connected to board and Arduino as well. When you remove object you will see it gets turned off. The sensor outputs a logic 1 (+5V) at the digital output when an object is placed in front of the sensor and a logic 0 (0V), when there is no object in front of the sensor. (On Serial Monitor Press Ctrl+Shift+M) Situation 1: When there is no obstacle in front of the sensor. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of Rain Drop Sensor with Arduino Uno. What is a Rain Drop Sensor? A raindrop sensor is a board on which nickel is coated in the form of lines. It works on the principle of resistance. The rain Sensor module allows the measurement of moisture via analog output pins and it provides a digital output when a threshold of moisture exceeds. The module is based on the LM393 op amp. It includes the electronics module and a printed circuit board that “collects” the rain drops. As raindrops are collected on the circuit board, they create paths of parallel resistance that are measured via the op amp. Material Required: Material Quantity Arduino Uno 1 Raindrop sensor 1 Jumper cables 4 Pinout Diagram: Circuit Diagram: Vcc +5 Volts Power Source GND Ground or negative power source A0 Analog Output – A0 Tested Programming Code: const int sensorMin = 0; const int sensorMax = 1024; void setup() { Serial.begin(9600); } void loop() { int sensorReading = analogRead(A0); int range = map(sensorReading, sensorMin, sensorMax, 0, 3); switch (range) { case 0: Serial.println("RAINING"); break; case 1: Serial.println("RAIN WARNING"); break; case 2: Serial.println("NOT RAINING"); break; } delay(1000); } Precautions: Double-check the connections before powering on the circuit. Don’t use loose jumper cables. Check whether the proper board is selected from Arduino IDE. Ensure proper placement of Rain drop Sensor for correct working. Don’t lose hope if Rain Drop Sensor does not run properly for the first time, try again. Conclusion: Once your sketch is running, you have to open your serial monitor. There you can see the Moisture or Rain on the Board. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of MQ2 (gas) sensor with Arduino Uno. What is a MQ2 (gas) Sensor? The Gas Sensor (MQ2) module is useful for gas leakage detection (home and industry). It is suitable for detecting H2, LPG, CH4, CO, Alcohol, Smoke or Propane. Due to its high sensitivity and fast response time, measurement can be taken as soon as possible. The sensitivity of the sensor can be adjusted by potentiometer. Material Required: Material Quantity Arduino Uno 1 MQ2 (gas) Sensor 1 Jumper cables 6 LED 1 Pinout Diagram: Circuit Diagram: Connect the pulse sensor with Arduino as follows: GND pin of MQ2 (gas) sensor to GND of Arduino VCC of MQ2 (gas) sensor to 5V of Arduino A0 of MQ2 (gas) sensor to A0 of Arduino D0 of MQ2 (gas) sensor to D2 of Arduino. If needed. After that, connect the LED to pin 13 and GND of Arduino as shown in the figure below. The LED will blink according to the MQ2 (gas) sensor. Tested Programming Code: Const int gaspin = A0; float sensorValue ; //variable to store sensor value void setup () { pinMode(gaspin,INPUT); Serial . begin ( 9600 ); // sets the serial port to 9600 Serial . println ( "Gas sensor warming up!" ); delay ( 20000 ); // allow the MQ-6 to warm up } void loop () { sensorValue = analogRead ( gaspin ); // read analog input pin 0 Serial . print ( "Sensor Value: " ); Serial . print ( sensorValue ); if ( sensorValue > 300 ) { Serial . print ( " | Smoke detected!" ); } Serial . println ( "" ); delay ( 2000 ); // wait 2s for next reading } Precautions: 1. Double check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether proper board is selected from Arduino IDE. 4. Ensure proper placement of MQ2 (gas) Sensor for correct working. 5. Don’t lose hope if Sensor does not run properly for the first time, try again. Conclusion: Once your sketch is running, you have to open your serial monitor. There you can see the value of gas present in air by the sensor. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of Force Pressure Sensor with Arduino Uno. What is a Force Pressure Sensor? An FSR (Force Sensitive Resistor) or Force Pressure Sensor is a sensor that allows you to measure physical pressure, weight and squeezing. The resistance of an FSR varies as the force on the sensor increases or decreases. When no pressure is being applied to the FSR, its resistance will be larger than 1MΩ. The harder you press on the sensor’s head, the lower the resistance between the two terminals drops. By combining the FSR with a static resistor to create a voltage divider, you can produce a variable voltage that can be read by a microcontroller’s analog-to-digital converter. Material Required: Material Quantity Arduino Uno 1 Force Pressure Sensor 1 Jumper cables 4 LED 1 Resistor 1 ( 10 k) Pinout Diagram: Circuit Diagram: The connections are pretty easy and straight forward. Make the circuit by referring the images. The FSR has two pins, one will be connected to 5V pin. The other to A0 directly and to Gnd pin via a resistor. If you need to connect the LED and control it's brightness, then connect it across pin 13 and Gnd of the Arduino. Tested Programming Code: int fsrPin = 0; // the FSR and 10K pulldown are connected to a0 int fsrReading; // the analog reading from the FSR resistor divider void setup(void) { Serial.begin(9600); } void loop(void) { fsrReading = analogRead(fsrPin); Serial.print("Analog reading = "); Serial.print(fsrReading); // the raw analog reading if (fsrReading == 0) { Serial.println(" - No pressure"); } else if (fsrReading < 10) { Serial.println(" - Light touch"); } else if (fsrReading < 50) { Serial.println(" - Light squeeze"); } else if (fsrReading < 150) { Serial.println(" - Medium squeeze"); } else { Serial.println(" - Big squeeze"); } delay(1000); } Precautions: 1. Double check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether proper board is selected from Arduino IDE. 4. Ensure proper placement of Force Pressure Sensor for correct working. 5. Don’t lose hope if Force Pressure Sensor does not run properly for the first time, try again. Conclusion: Once your sketch is running, you have to open your serial monitor. There you can see the Pressure applied on the sensor as Light , Big or No squeeze. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing 2 Channel Relay Module with Arduino and control High Voltage AC (current). What is a Relay Module? A Relay is a device that helps microcontrollers (or microcontroller-based boards) like Arduino to switch on or off different household appliances like motors, lights, water heaters, television, fans, etc. The relay module for Arduino is one of the most powerful applications for Arduino as it can be used to control both A.C and D.C devices by simply controlling the relay by giving 5V. A relay is a switch that is operated electrically by an electromagnet. A relay can be used to control high voltage electronic devices such as motors as well as low voltage electronic devices such as a light bulb or a fan. Relays work on the principle of electromagnetism. When the electricity is provided to the relay coil then it acts like a magnet and changes the state of the switch. The part which powers the relay module is completely isolated from the part which turns ON or OFF. This is why we can control a 220V appliance by simply controlling it using the 5V Arduino. you should also read getting started projects of Arduino. Material Required: Material Quantity Arduino Uno 1 Relay module (2 Channel) 1 Jumper cables 6 Switching Source 1 Cable, Plug, Socket 1 Pinout Diagram: HL-52S Relay Module As an example, for this Arduino Relay Tutorial, we will use the HL-52S 2 channel relay module, which has 2 relays with a rating of 10A @ 250 and 125 V AC and 10A @ 30 and 28 V DC. The high voltage output connector has 3 pins, the middle one is the common pin, and as we can see from the markings one of the two other pins is for a normally open connection and the other one for a normally closed connection. On the other side of the module, we have these 2 sets of pins. The first one has 4 pins, a Ground and a VCC pin for powering the module, and 2 input pins In1 and In2. The second set of pins has 3 pins with a jumper between the JDVcc and the Vcc pin. With a configuration like this, the electromagnet of the relay is directly powered by the Arduino Board and if something goes wrong with the relay the microcontroller could get damaged. Circuit Diagram: For better understanding let’s see the circuit schematics of the relay module in this configuration. So we can see that the 5 volts from our microcontroller connected to the Vcc pin for activating the relay through the Optocoupler IC are also connected to the JDVcc pin which powers the electromagnet of the relay. So in this case we got no isolation between the relay and the microcontroller. To isolate the microcontroller from the relay, we need to remove the jumper and connect a separate power supply for the electromagnet to the JDVcc and the Ground pin. Now with this configuration, the microcontroller doesn’t have any physical connection with the relay, it just uses the LED light of the Optocoupler IC to activate the relay. There is one more thing to be noticed from this circuit schematics. The input pins of the module work inversely. As we can see the relay will be activated when the input pin will be LOW because in that way the current will be able to flow from the VCC to the input pin which is low or ground, and the LED will light up and activate the relay. When the input pin will be HIGH there will be no current flow, so the LED will not light up and the relay will not be activated. High Voltage Warning Before we continue with this tutorial, I will warn you here that we will use High Voltage which if incorrectly or improperly used could result in serious injuries or death. So be very cautious of what you are doing because I take no responsibility for any of your actions. How to use the relay module with the High Voltage devices First, let’s take a look at the circuit diagram. As previously described we will use a 5V Adapter as a separate power supply for the electromagnet connected to the JDVcc and the Ground pin. The Arduino’s 5V pin will be connected to the Vcc pin of the module and PIN 7 to the In1 input pin for controlling the relay. Now for the HIGH Voltage part, we need a power plug, a socket, and a cable with two wires. One of the two wires will be cut and connected to the common and the normally open pin of the module output connector. So with this configuration when we will activate the relay we will get the high voltage circuit closed and working. Here’s how made the cable. So I bought a plug, a socket, and a cable. Then I carefully cut the cable and cut one of the wires as shown in the picture below and connect them to the normally open connection pins of the relay module. Also connected the ends of the cable to the plug and the socket. Tested Programming Code: Now what’s left for this tutorial is to make a simple code and test the relay module and how it will work. Here’s the simple code, we will just use the PIN 7 for controlling the relay, so we will define it as output and make a program that will just activate and deactivate the relay every 3 seconds. I will mention once again here that the input of the module works inversely so a logic low at the input will activate the relay and vice versa. int in1 = 7; void setup() { pinMode(in1, OUTPUT); digitalWrite(in1, HIGH); } void loop() { digitalWrite(in1, LOW);delay(3000); digitalWrite(in1, HIGH); delay(3000); } There is a demonstration of this example at the end of the video of this tutorial. I tested 3 devices on it. First a 100W light bulb, then a desk lamp, and a fan heater. All of these devices work on 220V. Precautions: 1. Double-check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether the proper board is selected from Arduino IDE. 4. Ensure proper placement of Relay Module for correct working. 5. Use proper measures before using AC electricity. Conclusion: So that’s how we can control any High Voltage Device using Arduino or any other microcontroller. And of course, the possibilities are now endless, for example, we can control the devices using a TV Remote, Bluetooth, SMS, Internet, and so on. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of 4 Digit Segment Display with Arduino Uno. What is a 4 digit segment display? A seven-segment display ( SSD ), or seven-segment indicator , is a form of an electronic display device for displaying decimal numerals that is an alternative to the more complex dot matrix displays. Seven-segment displays are widely used in digital clocks, electronic meters, basic calculators, and other electronic devices that display numerical information. Material Required: Material Quantity Arduino Uno 1 4-digit segment display 1 Jumper cables 4 Pin of 4-digit segment display: 1. GND. 2. VCC. 3. DIO. 4. CLK. Circuit Diagram: Connect the 4 Digit Segment Display with Arduino as follows: GND pin of 4 Digit Segment Display to GND of Arduino VCC pin of 4 Digit Segment Display to 5V of Arduino DIO pin of 4 Digit Segment Display to digital pin 2 of Arduino CLK pin of 4 Digit Segment Display to digital pin 3 of Arduino Library Required You have to download the library for Arduino of 4 Digit Segment Display The link is given below: https://github.com/avishorp/TM1637 Tested Programming Code: #include //Set the CLK pin connection to the display const int CLK = 3 ; //Set the DIO pin connection to the display const int DIO = 2 ; int numCounter = 0 ; //set up the 4-Digit Display. TM1637Display display ( CLK, DIO ) ; void setup () { //set the diplay to maximum brightness display. setBrightness ( 0x0a ) ; } void loop () { //Iterate numCounter for ( numCounter = 0 ; numCounter < 1000 ; numCounter++ ) { //Display the numCounter value; display. showNumberDec ( numCounter ) ; delay ( 1000 ) ; } } Precautions: 1. Double-check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether the proper board is selected from Arduino IDE. 4. Ensure proper placement of 4-digit segment display for correct working. Conclusion: Once your sketch is running, you have to see the 4-digit segment display. It starts display. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of GSM 800 L Modules with Arduino. What is a GSM Module ? The SIM800L is a cheap and portable GSM breakout board with all the capabilities of the larger SIM900 shields. In this Arduino SIM800L tutorial, I will help you get started with this nifty device. Sending and receiving texts with your Arduino have never been easier! SIM800L Introduction Here are the features of the SIM800L breakout board: 2G quad-band @ 850/900/1800/1900 MHz Receive and make calls using the speaker and microphone outputs Receive and send SMS Connect to the Internet via GPRS Listen to FM radio broadcasts Accepts AT Commands From the specification of SIM800L we would able to find out that its: Operating Voltage: 3.3 - 5 Volts Recommended voltage: 3.4 - 4.4 Volts Recommended Current: 1 – 2 Amp Therefore, if we use voltages below 3.4, either the SIM800L will not work or it will work but not all its features are responding (e.g unable to read SIM card). But if use voltage equal to its MAXIMUM operating voltage, the module might heat up and then got destroyed, or if we use ABOVE operating voltage, well, it will absolutely destroy the module. Most important, we should not supply a current above 2 Amp (e.g 5 Amp) to the module, it will destroy the module even if your voltage is in 3.4 - 4.4 volts range. But here in our tutorial, you will observe that the module get 5V supply from arduino. That’s sound risky, but as my measurement, computation and observation, 5V pin in Arduino generate current from 500mA -1 Amp which gives a maximum power of 5 Watts. 5 watts qualifies from recommended power which would not cause the module to heat up or destroyed. That’s why 5V pin in Arduino qualifies as a supply voltage. If the power to the SIM800L is enough, the on-board LED starts blinking. The frequency of the blinking means something: Every second: searching for a network. Every three seconds: connected to a network. Twice per second: connected through GPRS. Antennas are essential for this kind of module especially if your project is indoors. Without an antenna, there would not be enough transmitting power for the SIM800L to perform GSM services such as calls and SMS. Material Required: Material Quantity Arduino Uno 1 SIM 800L 1 Jumper cables 6 Breadboard 1 Pinout Diagram: Circuit Diagram: Note: Make sure you already inserted your SIM card before powering the module. If not, you will not see any changes in the module LED indicator. SIM800 VCC ↔ Arduino 5v SIM800 GND ↔ Arduino GND SIM800 SIM_TXD ↔ Arduino pin 3 SIM800 SIM_RXD ↔ Arduino pin 2 Step 2: Code Download and Add Adafriut Fona library to your Arduino library. Then open and upload the Fonatest sample code from Adafruit Fona. Open Serial monitor then change baudrate to 115200 and choose NL & CR. Then you'll see Menu of test setup, choose anything you want to test (e.g send and receive message). Tested Programming Code: #include "Adafruit_FONA.h" #define FONA_RX 2 #define FONA_TX 3 #define FONA_RST 4 // this is a large buffer for replies char replybuffer[255]; // We default to using software serial. If you want to use hardware serial // (because softserial isnt supported) comment out the following three lines // and uncomment the HardwareSerial line #include SoftwareSerial fonaSS = SoftwareSerial(FONA_TX, FONA_RX); SoftwareSerial *fonaSerial = &fonaSS; // Hardware serial is also possible! // HardwareSerial *fonaSerial = &Serial1; // Use this for FONA 800 and 808s Adafruit_FONA fona = Adafruit_FONA(FONA_RST); // Use this one for FONA 3G //Adafruit_FONA_3G fona = Adafruit_FONA_3G(FONA_RST); uint8_t readline(char *buff, uint8_t maxbuff, uint16_t timeout = 0); uint8_t type; void setup() { while (!Serial); Serial.begin(115200); Serial.println(F("FONA basic test")); Serial.println(F("Initializing.. (May take 3 seconds)")); fonaSerial->begin(4800); if (! fona.begin(*fonaSerial)) { Serial.println(F("Couldn't find FONA")); while (1); } type = fona.type(); Serial.println(F("FONA is OK")); Serial.print(F("Found ")); switch (type) { case FONA800L: Serial.println(F("FONA 800L")); break; case FONA800H: Serial.println(F("FONA 800H")); break; case FONA808_V1: Serial.println(F("FONA 808 (v1)")); break; case FONA808_V2: Serial.println(F("FONA 808 (v2)")); break; case FONA3G_A: Serial.println(F("FONA 3G (American)")); break; case FONA3G_E: Serial.println(F("FONA 3G (European)")); break; default: Serial.println(F("???")); break; } // Print module IMEI number. char imei[16] = {0}; // MUST use a 16 character buffer for IMEI! uint8_t imeiLen = fona.getIMEI(imei); if (imeiLen > 0) { Serial.print("Module IMEI: "); Serial.println(imei); } // Optionally configure a GPRS APN, username, and password. // You might need to do this to access your network's GPRS/data // network. Contact your provider for the exact APN, username, // and password values. Username and password are optional and // can be removed, but APN is required. //fona.setGPRSNetworkSettings(F("your APN"), F("your username"), F("your password")); // Optionally configure HTTP gets to follow redirects over SSL. // Default is not to follow SSL redirects, however if you uncomment // the following line then redirects over SSL will be followed. //fona.setHTTPSRedirect(true); printMenu(); } void printMenu(void) { Serial.println(F(" ")); Serial.println(F("[?] Print this menu")); Serial.println(F("[a] read the ADC 2.8V max (FONA800 & 808)")); Serial.println(F("[b] read the Battery V and % charged")); Serial.println(F("[C] read the SIM CCID")); Serial.println(F("[U] Unlock SIM with PIN code")); Serial.println(F("[i] read RSSI")); Serial.println(F("[n] get Network status")); Serial.println(F("[v] set audio Volume")); Serial.println(F("[V] get Volume")); Serial.println(F("[H] set Headphone audio (FONA800 & 808)")); Serial.println(F("[e] set External audio (FONA800 & 808)")); Serial.println(F("[T] play audio Tone")); Serial.println(F("[P] PWM/Buzzer out (FONA800 & 808)")); // FM (SIM800 only!) Serial.println(F("[f] tune FM radio (FONA800)")); Serial.println(F("[F] turn off FM (FONA800)")); Serial.println(F("[m] set FM volume (FONA800)")); Serial.println(F("[M] get FM volume (FONA800)")); Serial.println(F("[q] get FM station signal level (FONA800)")); // Phone Serial.println(F("[c] make phone Call")); Serial.println(F("[A] get call status")); Serial.println(F("[h] Hang up phone")); Serial.println(F("[p] Pick up phone")); // SMS Serial.println(F("[N] Number of SMSs")); Serial.println(F("[r] Read SMS #")); Serial.println(F("[R] Read All SMS")); Serial.println(F("[d] Delete SMS #")); Serial.println(F("[s] Send SMS")); Serial.println(F("[u] Send USSD")); // Time Serial.println(F("[y] Enable network time sync (FONA 800 & 808)")); Serial.println(F("[Y] Enable NTP time sync (GPRS FONA 800 & 808)")); Serial.println(F("[t] Get network time")); // GPRS Serial.println(F("[G] Enable GPRS")); Serial.println(F("[g] Disable GPRS")); Serial.println(F("[l] Query GSMLOC (GPRS)")); Serial.println(F("[w] Read webpage (GPRS)")); Serial.println(F("[W] Post to website (GPRS)")); // GPS if ((type == FONA3G_A) || (type == FONA3G_E) || (type == FONA808_V1) || (type == FONA808_V2)) { Serial.println(F("[O] Turn GPS on (FONA 808 & 3G)")); Serial.println(F("[o] Turn GPS off (FONA 808 & 3G)")); Serial.println(F("[L] Query GPS location (FONA 808 & 3G)")); if (type == FONA808_V1) { Serial.println(F("[x] GPS fix status (FONA808 v1 only)")); } Serial.println(F("[E] Raw NMEA out (FONA808)")); } Serial.println(F("[S] create Serial passthru tunnel")); Serial.println(F(" ")); Serial.println(F("")); } void loop() { Serial.print(F("FONA> ")); while (! Serial.available() ) { if (fona.available()) { Serial.write(fona.read()); } } char command = Serial.read(); Serial.println(command); switch (command) { case '?': { printMenu(); break; } case 'a': { // read the ADC uint16_t adc; if (! fona.getADCVoltage(&adc)) { Serial.println(F("Failed to read ADC")); } else { Serial.print(F("ADC = ")); Serial.print(adc); Serial.println(F(" mV")); } break; } case 'b': { // read the battery voltage and percentage uint16_t vbat; if (! fona.getBattVoltage(&vbat)) { Serial.println(F("Failed to read Batt")); } else { Serial.print(F("VBat = ")); Serial.print(vbat); Serial.println(F(" mV")); } if (! fona.getBattPercent(&vbat)) { Serial.println(F("Failed to read Batt")); } else { Serial.print(F("VPct = ")); Serial.print(vbat);Serial.println(F("%")); } break; } case 'U': { // Unlock the SIM with a PIN code char PIN[5]; flushSerial(); Serial.println(F("Enter 4-digit PIN")); readline(PIN, 3); Serial.println(PIN); Serial.print(F("Unlocking SIM card: ")); if (! fona.unlockSIM(PIN)) { Serial.println(F("Failed")); } else { Serial.println(F("OK!")); } break; } case 'C': { // read the CCID fona.getSIMCCID(replybuffer); // make sure replybuffer is at least 21 bytes! Serial.print(F("SIM CCID = ")); Serial.println(replybuffer); break; } case 'i': { // read the RSSI uint8_t n = fona.getRSSI(); int8_t r; Serial.print(F("RSSI = ")); Serial.print(n); Serial.print(": "); if (n == 0) r = -115; if (n == 1) r = -111; if (n == 31) r = -52; if ((n >= 2) && (n <= 30)) { r = map(n, 2, 30, -110, -54); } Serial.print(r); Serial.println(F(" dBm")); break; } case 'n': { // read the network/cellular status uint8_t n = fona.getNetworkStatus(); Serial.print(F("Network status ")); Serial.print(n); Serial.print(F(": ")); if (n == 0) Serial.println(F("Not registered")); if (n == 1) Serial.println(F("Registered (home)")); if (n == 2) Serial.println(F("Not registered (searching)")); if (n == 3) Serial.println(F("Denied")); if (n == 4) Serial.println(F("Unknown")); if (n == 5) Serial.println(F("Registered roaming")); break; } /*** Audio ***/ case 'v': { // set volume flushSerial(); if ( (type == FONA3G_A) || (type == FONA3G_E) ) { Serial.print(F("Set Vol [0-8] ")); } else { Serial.print(F("Set Vol % [0-100] ")); } uint8_t vol = readnumber(); Serial.println(); if (! fona.setVolume(vol)) { Serial.println(F("Failed")); } else { Serial.println(F("OK!")); } break; } case 'V': { uint8_t v = fona.getVolume(); Serial.print(v); if ( (type == FONA3G_A) || (type == FONA3G_E) ) { Serial.println(" / 8"); } else { Serial.println("%"); } break; } case 'H': { // Set Headphone output if (! fona.setAudio(FONA_HEADSETAUDIO)) { Serial.println(F("Failed")); } else { Serial.println(F("OK!")); } fona.setMicVolume(FONA_HEADSETAUDIO, 15); break; } case 'e': { // Set External output if (! fona.setAudio(FONA_EXTAUDIO)) { Serial.println(F("Failed")); } else { Serial.println(F("OK!")); } fona.setMicVolume(FONA_EXTAUDIO, 10); break; } case 'T': { // play tone flushSerial(); Serial.print(F("Play tone #")); uint8_t kittone = readnumber(); Serial.println(); // play for 1 second (1000 ms) if (! fona.playToolkitTone(kittone, 1000)) { Serial.println(F("Failed")); } else { Serial.println(F("OK!")); } break; } case 'f': { // get freq flushSerial(); Serial.print(F("FM Freq (eg 1011 == 101.1 MHz): ")); uint16_t station = readnumber(); Serial.println(); // FM radio ON using headset if (fona.FMradio(true, FONA_HEADSETAUDIO)) { Serial.println(F("Opened")); } if (! fona.tuneFMradio(station)) { Serial.println(F("Failed")); } else { Serial.println(F("Tuned")); } break; } case 'F': { // FM radio off if (! fona.FMradio(false)) { Serial.println(F("Failed")); } else { Serial.println(F("OK!")); } break; } case 'm': { // Set FM volume. flushSerial(); Serial.print(F("Set FM Vol [0-6]:")); uint8_t vol = readnumber(); Serial.println(); if (!fona.setFMVolume(vol)) { Serial.println(F("Failed")); } else { Serial.println(F("OK!")); } break; case 'M': { // Get FM volume. uint8_t fmvol = fona.getFMVolume(); if (fmvol < 0) { Serial.println(F("Failed")); } else { Serial.print(F("FM volume: ")); Serial.println(fmvol, DEC); } break; } case 'q': { // Get FM station signal level (in decibels). flushSerial(); Serial.print(F("FM Freq (eg 1011 == 101.1 MHz): ")); uint16_t station = readnumber(); Serial.println(); int8_t level = fona.getFMSignalLevel(station); if (level < 0) { Serial.println(F("Failed! Make sure FM radio is on (tuned to station).")); } else { Serial.print(F("Signal level (dB): ")); Serial.println(level, DEC); } break; } /*** PWM ***/ case 'P': { // PWM Buzzer output @ 2KHz max flushSerial(); Serial.print(F("PWM Freq, 0 = Off, (1-2000): ")); uint16_t freq = readnumber(); Serial.println(); if (! fona.setPWM(freq)) { break; } /*** Call ***/ case 'c': { // call a phone! char number[30]; flushSerial(); Serial.print(F("Call #")); readline(number, 30); Serial.println(); Serial.print(F("Calling ")); Serial.println(number); if (!fona.callPhone(number)) { Serial.println(F("Failed")); } else { Serial.println(F("Sent!")); } break; } case 'A': { // get call status int8_t callstat = fona.getCallStatus(); switch (callstat) { case 0: Serial.println(F("Ready")); break; case 1: Serial.println(F("Could not get status")); break; case 3: Serial.println(F("Ringing (incoming)")); break; case 4: Serial.println(F("Ringing/in progress (outgoing)")); break; default: Serial.println(F("Unknown")); break; } break; } case 'h': { // hang up! if (! fona.hangUp()) { break; } case 'p': { // pick up! if (! fona.pickUp()) { Serial.println(F("Failed")); } else { Serial.println(F("OK!")); } break; } /*** SMS ***/ case 'N': { // read the number of SMS's! int8_t smsnum = fona.getNumSMS(); if (smsnum < 0) { Serial.println(F("Could not read # SMS")); } else { Serial.print(smsnum); Serial.println(F(" SMS's on SIM card!")); } break; } case 'r': { // read an SMS flushSerial(); Serial.print(F("Read #")); uint8_t smsn = readnumber(); Serial.print(F("\n\rReading SMS #")); Serial.println(smsn); // Retrieve SMS sender address/phone number. if (! fona.getSMSSender(smsn, replybuffer, 250)) { Serial.println("Failed!"); break; } Serial.print(F("FROM: ")); Serial.println(replybuffer); // Retrieve SMS value. uint16_t smslen; if (! fona.readSMS(smsn, replybuffer, 250, &smslen)) { // pass in buffer and max len! Serial.println("Failed!"); break; } Serial.print(F("***** SMS #")); Serial.print(smsn); Serial.print(" ("); Serial.print(smslen); Serial.println(F(") bytes *****")); Serial.println(replybuffer); Serial.println(F("*****")); break; } case 'R': { // read all SMS int8_t smsnum = fona.getNumSMS(); uint16_t smslen; int8_t smsn; if ( (type == FONA3G_A) || (type == FONA3G_E) ) { smsn = 0; // zero indexed smsnum--; } else { smsn = 1; // 1 indexed } for ( ; smsn <= smsnum; smsn++) { Serial.print(F("\n\rReading SMS #")); Serial.println(smsn); if (!fona.readSMS(smsn, replybuffer, 250, &smslen)) { // pass in buffer and max len! Serial.println(F("Failed!")); break; } // if the length is zero, its a special case where the index number is higher // so increase the max we'll look at! if (smslen == 0) { Serial.println(F("[empty slot]")); smsnum++; continue; } Serial.print(F("***** SMS #")); Serial.print(smsn); Serial.print(" ("); Serial.print(smslen); Serial.println(F(") bytes *****")); Serial.println(replybuffer); Serial.println(F("*****")); } break; } case 'd': { // delete an SMS flushSerial(); Serial.print(F("Delete #")); uint8_t smsn = readnumber(); Serial.print(F("\n\rDeleting SMS #")); Serial.println(smsn); if (fona.deleteSMS(smsn)) { Serial.println(F("OK!")); } else { Serial.println(F("Couldn't delete")); } break; } case 's': { // send an SMS! char sendto[21], message[141]; flushSerial(); Serial.print(F("Send to #")); readline(sendto, 20); Serial.println(sendto); Serial.print(F("Type out one-line message (140 char): ")); readline(message, 140); Serial.println(message); if (!fona.sendSMS(sendto, message)) { Serial.println(F("Failed")); } else { Serial.println(F("Sent!")); } break; } case 'u': { // send a USSD! char message[141]; flushSerial(); Serial.print(F("Type out one-line message (140 char): ")); readline(message, 140); Serial.println(message); uint16_t ussdlen; if (!fona.sendUSSD(message, replybuffer, 250, &ussdlen)) { // pass in buffer and max len! Serial.println(F("Failed")); } else { Serial.println(F("Sent!")); Serial.print(F("***** USSD Reply")); Serial.print(" ("); Serial.print(ussdlen); Serial.println(F(") bytes *****")); Serial.println(replybuffer); Serial.println(F("*****")); } } /*** Time ***/ case 'y': { // enable network time sync if (!fona.enableNetworkTimeSync(true)) Serial.println(F("Failed to enable")); break; } case 'Y': { // enable NTP time sync if (!fona.enableNTPTimeSync(true, F("pool.ntp.org"))) Serial.println(F("Failed to enable")); break; } case 't': { // read the time char buffer[23]; fona.getTime(buffer, 23); // make sure replybuffer is at least 23 bytes! Serial.print(F("Time = ")); Serial.println(buffer); break; } /*********************************** GPS (SIM808 only) */ case 'o': { // turn GPS off if (!fona.enableGPS(false)) Serial.println(F("Failed to turn off")); break; } case 'O': { // turn GPS on if (!fona.enableGPS(true)) Serial.println(F("Failed to turn on")); break; } case 'x': { int8_t stat; // check GPS fix stat = fona.GPSstatus(); if (stat < 0) Serial.println(F("Failed to query")); if (stat == 0) Serial.println(F("GPS off")); if (stat == 1) Serial.println(F("No fix")); if (stat == 2) Serial.println(F("2D fix")); if (stat == 3) Serial.println(F("3D fix")); break; } case 'L': { // check for GPS location char gpsdata[120]; fona.getGPS(0, gpsdata, 120); if (type == FONA808_V1) Serial.println(F("Reply in format: mode,longitude,latitude,altitude,utctime(yyyymmddHHMMSS),ttff,satellites,speed,course")); else Serial.println(F("Reply in format: mode,fixstatus,utctime(yyyymmddHHMMSS),latitude,longitude,altitude,speed,course,fixmode,reserved1,HDOP, PDOP,VDOP,reserved2,view_satellites,used_satellites,reserved3,C/N0max,HPA,VPA")); Serial.println(gpsdata); break; } case 'E': { flushSerial(); if (type == FONA808_V1) { Serial.print(F("GPS NMEA output sentences (0 = off, 34 = RMC+GGA, 255 = all)")); } else { Serial.print(F("On (1) or Off (0)? ")); } uint8_t nmeaout = readnumber(); // turn on NMEA output fona.enableGPSNMEA(nmeaout); break; } /*********************************** GPRS */ case 'g': { // turn GPRS off if (!fona.enableGPRS(false)) Serial.println(F("Failed to turn off")); break; } case 'G': { // turn GPRS on if (!fona.enableGPRS(true)) Serial.println(F("Failed to turn on")); break; } case 'l': { // check for GSMLOC (requires GPRS) uint16_t returncode; if (!fona.getGSMLoc(&returncode, replybuffer, 250)) Serial.println(F("Failed!")); if (returncode == 0) { Serial.println(replybuffer); } else { Serial.print(F("Fail code #")); Serial.println(returncode); } break; } case 'w': { // read website URL uint16_t statuscode; int16_t length; char url[80]; flushSerial(); Serial.println(F("NOTE: in beta! Use small webpages to read!")); Serial.println(F("URL to read (e.g. www.adafruit.com/testwifi/index.html):") ); Serial.print(F("http://")); readline(url, 79); Serial.println(url); Serial.println(F("****")); if (!fona.HTTP_GET_start(url, &statuscode, (uint16_t *)&length)){ Serial.println("Failed!"); break; } while (length > 0) { while (fona.available()) { char c = fona.read(); // Serial.write is too slow, we'll write directly to Serial register! #if defined(AVR_ATmega328P ) || defined( AVR_ATmega168) loop_until_bit_is_set(UCSR0A, UDRE0); /* Wait until data register empty. */ UDR0 = c; #else #endif } Serial.write(c); length--; if (! length) break; } Serial.println(F("\n****")); fona.HTTP_GET_end(); break; } case 'W': { // Post data to website uint16_t statuscode; int16_t length; char url[80]; char data[80]; flushSerial(); Serial.println(F("NOTE: in beta! Use simple websites to post!")); Serial.println(F("URL to post (e.g. httpbin.org/post):")); Serial.print(F("http://")); readline(url, 79); Serial.println(url); Serial.println(F("Data to post (e.g. \"foo\" or \"{\"simple\":\"json\"}\"):")); readline(data, 79); Serial.println(data); Serial.println(F("****")); if (!fona.HTTP_POST_start(url, F("text/plain"), (uint8_t *) data, strlen(data), &statuscode, (uint16_t *)&length)) { Serial.println("Failed!"); break; } while (length > 0) { while (fona.available()) { char c = fona.read(); #if defined( AVR_ATmega328P ) || defined( AVR_ATmega168 ) loop_until_bit_is_set(UCSR0A, UDRE0); /* Wait until data register empty. */ UDR0 = c; #else #endif Serial.write(c); length--; if (! length) break; } } Serial.println(F("\n****")); fona.HTTP_POST_end(); break; } /*****************************************/ case 'S': { Serial.println(F("Creating SERIAL TUBE")); while (1) { while (Serial.available()) { delay(1); fona.write(Serial.read()); } if (fona.available()) { Serial.write(fona.read()); } } break; } default: { Serial.println(F("Unknown command")); printMenu(); break; } } // flush input flushSerial(); while (fona.available()) { Serial.write(fona.read()); } } void flushSerial() { while (Serial.available()) Serial.read(); } char readBlocking() { while (!Serial.available()); return Serial.read(); } uint16_t readnumber() { uint16_t x = 0; char c; while (! isdigit(c = readBlocking())) { //Serial.print(c); } Serial.print(c); x = c - '0'; while (isdigit(c = readBlocking())) { Serial.print(c); x *= 10; x += c - '0'; } return x; } uint8_t readline(char *buff, uint8_t maxbuff, uint16_t timeout) { uint16_t buffidx = 0; boolean timeoutvalid = true; if (timeout == 0) timeoutvalid = false; while (true) { if (buffidx > maxbuff) { //Serial.println(F("SPACE")); break; } while (Serial.available()) { char c = Serial.read(); //Serial.print(c, HEX); Serial.print("#"); Serial.println(c); if (c == '\r') continue; if (c == 0xA) { if (buffidx == 0) // the first 0x0A is ignored continue; timeout = 0; // the second 0x0A is the end of the line timeoutvalid = true; break; } buff[buffidx] = c; buffidx++; } if (timeoutvalid && timeout == 0) { //Serial.println(F("TIMEOUT")); break; } delay(1); } buff[buffidx] = 0; // null term return buffidx; } Precautions: 1. Double check the connections before powering on thecircuit. 2. Don’t use loose jumper cables. 3. Check whether proper board is selected from ArduinoIDE. 4. Ensure proper placement of sensor for correct working. 5. Don’t lose hope if Flex Sensor or LED does not runs properly for the first time, try again. Conclusion: You can successfully interface different devices using the Resistance principle of Flex Sensor.s Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing with MQ-3 Alcohol Sensor Module MQ-3 gas sensor has high sensitivity to alcohol, and has good resistance to disturbances of gasoline, smoke and vapor. The sensor could be used to detect alcohol with different concentration; it is with low cost and suitable for different application. Sensitive material of MQ-3 gas sensor is SnO2, which with lower conductivity in clean air. When the target alcohol gas exists, sensor’s conductivity is proportional to the gas concentration. Description: 1. Model No: MQ-3. 2. Heater voltage: 5±0.2V. 3. Loop voltage: ≤24V (DC) 4. Load resistance: Adjustable. 5. Heating Resistance: 31Ω±3Ω (Room temperature). 6. Heating Power: ≤ 900mW. 7. Surface thermal resistance: 2Kohm-20Kohm (0.4mg/L alcohol). 8. Sensitivity: Rs (in air)/Rs (0.4mg/L alcohol) ≥ 5. Application Example with Arduino Uno: Connect the MQ-3 alcohol sensor module to Arduino Uno board as shown below: Programming Code /* MQ-3 Alcohol Sensor Circuit with Arduino */ const int AOUTpin=A0; //the AOUT pin of the alcohol sensor goes into analog pin A0 of the arduino const int DOUTpin=8; //the DOUT pin of the alcohol sensor goes into digital pin D8 of the arduino const int ledPin=13; //the anode of the LED connects to digital pin D13 of the arduino int limit; int value; void setup() { Serial.begin(115200); pinMode(DOUTpin, INPUT); pinMode(ledPin, OUTPUT); } void loop() { value= analogRead(AOUTpin); //reads the analaog value from the alcohol sensor's AOUT pin limit= digitalRead(DOUTpin); //reads the digital value from the alcohol sensor's DOUT pin Serial.print(" Alcohol value: "); Serial.println(value); //prints the alcohol value Serial.print("Limit: "); Serial.print(limit); //prints the limit reached as either LOW or HIGH (above or underneath) delay(100); if (limit == HIGH) { digitalWrite(ledPin, HIGH);//if limit has been reached, LED turns on as status indicator } else{ digitalWrite(ledPin, LOW); //if threshold not reached, LED remains off } } Result: Open up the Serial Monitor with Baud rate of 115200, the alcohol level detected will be shown as analog value. The alcohol limit value can be set with sensitivity potentiometer: if the alcohol level detected is below the set limit, the D0 green indicator will be off. If detected alcohol level is beyond the set limit, the DO LED will light up. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of Touch Sensor with Arduino Uno. What is a Touch Sensor? This device uses your body as part of the circuit. When you touch the sensor pad, the capacitance of the circuit is changed and is detected. That detected change in capacitance results in the output changing states. Material Required: Material Quantity Arduino Uno 1 Touch Sensor 1 Jumper cables 4 Pinout Diagram: Pin of Touch sensor: 1. GND. 2. VCC. 3. SIG Circuit Diagram: Connect the Touch Sensor with Arduino as follows: GND pin of Touch sensor to GND of Arduino VCC pin of Touch Sensor to 5V of Arduino SIG pin of Touch Sensor to digital pin 2 of Arduino. Tested Programming Code: #define ctsPin 2 int ledPin = 13; // pin for the LED void setup() { Serial.begin(9600); pinMode(ledPin, OUTPUT); pinMode(ctsPin, INPUT); } void loop() { int ctsValue = digitalRead(ctsPin); if (ctsValue==HIGH) { digitalWrite(ledPin, HIGH); Serial.println("TOUCHED"); } else{ digitalWrite(ledPin,LOW); Serial.println("not touched"); } delay(500); } Precautions: Double check the connections before powering on the circuit. Don’t use loose jumper cables. Check whether proper board is selected from Arduino IDE. Ensure proper placement of Touch Sensor for correct working. Conclusion: Once your sketch is running, you have to see the Touch Sensor working by seeing the Serial monitor whenever it is being touched. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back 4*4 Keypad Interfacing with Arduino UNO. What is a 4*4 Keypad? In embedded devices one of the essential parts is Keypad is used to interact with embedded devices, Keypad is an input device that is used to give the command to the devices, from the calculator to the computer input is given through the keypad. 4×4 Matrix Keypad and how the Arduino Keypad Interface works. A Keypad is an input device that is used to enter passwords, dial a number, browse through the menu and even control robots. Material Required: Material Quantity Arduino Uno 1 4*4 Keypad 1 Jumper cables 8 Pinout Diagram: If you have a keypad look for one below. The below diagram is enough for knowing pin configuration. Circuit Diagram: Follow the given pin order for wiring the circuit. As shown in the left diagram. Start from left to right. Keypad Pin 1 (R4) –> Arduino Pin 2 Keypad Pin 2 (R3) –> Arduino Pin 3 Keypad Pin 3 (R2) –> Arduino Pin 4 Keypad Pin 5 (C4) –> Arduino Pin 6 Keypad Pin 6 (C3) –> Arduino Pin 7 Keypad Pin 7 (C2) –> Arduino Pin 8 Keypad Pin 8 (C1) –> Arduino Pin 9 Tested Programming Code: /* ##### 4x4 Membrane Keypad Arduino Interfacing #####Arduino and Keypad Connection Keypad Pin => Arduino Pin 1 => Digital Pin 2 2 => Digital Pin 3 3 => Digital Pin 4 4 => Digital Pin 5 5 => Digital Pin 6 6 => Digital Pin 7 7 => Digital Pin 8 8 => Digital Pin 9* #include const byte ROWS = 4; //four rows const byte COLS = 4; //four columns // Define the Keymap char hexaKeys[ROWS][COLS] = { {'1','2','3','A'}, {'4','5','6','B'}, {'7','8','9','C'}, {'*','0','#','D'} }; byte rowPins[ROWS] = {9, 8, 7, 6}; //connect to the Rows of the keypad pin 8, 7, 6, 5 respectively byte colPins[COLS] = {5, 4, 3, 2}; //connect to the Columns of the keypad pin 4, 3, 2, 1 respectively //initialize an instance of class NewKeypad Keypad customKeypad = Keypad( makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS); void setup (){ Serial.begin(9600); } void loop (){ char customKey = customKeypad.getKey(); if (customKey){ Serial.println(customKey); // Send the pressed key value to the arduino serial monitor } } Checking Values on Serial Monitor: After successfully uploading the Program to the Arduino Board, You can check the input given through the keypad on the Serial monitor. Precautions: 1. Double-check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether the proper board is selected from Arduino IDE. 4. Ensure proper placement of sensor for correct working. 5. Connect the Wiper pin of the potentiometer correctly. 6. Don’t lose hope if Keypad does not run properly for the first time, try again Conclusion: You can successfully display inputs given in the keypad on the Serial Monitor in the simplest way using Arduino. Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Character Displaying using 8X8 LED Matrix MAX7219 with Arduino Uno What is a Matrix Display? Dot-matrix LED display contains the group of LEDs as a two-dimensional array. They can display different types of characters or a group of characters. Dot-matrix LED display contains the group of LEDs as a two-dimensional array. They can display different types of characters or a group of characters. Dot-matrix display is manufactured in various dimensions. The arrangement of LEDs in the matrix pattern is made in either of the two ways: Row anode-column cathode or Row cathode-column anode. By using this dot matrix display we can reduce the number of pins required for controlling all the LEDs. Material Required: Material Quantity Arduino Uno 1 MAX 7219 Display Module 1 Jumper cables 5 Pinout Diagram: Circuit Diagram: Working: An LED dot matrix consists of an array of LEDs that are connected such that the anode of each LED is connected in the same column and the cathode of each LED is connected in the same row or vice versa . Here each dot represents circular lenses in front of LEDs. This is done to minimize the number of pins required to drive them. For example, an 8X8 matrix of LEDs would need 64 I/O pins, one for each LED pixel. By connecting all the anodes of LEDs in a column and all the cathodes together in a row, the required number of input and output pins is reduced to 16. Each LED will be addressed by its row and column number. Controlling the LED Matrix: Since all the LEDs in a matrix share their positive and negative terminals in each row and column, it is not possible controlling of each LED at the same time. The matrix controlled through each row very quickly by triggering the correct column pins to light the desired LED for that particular row. If the switching is done with a fixed rate, humans can’t see the displaying message, because the human eye can’t detect the images within the milliseconds. Thus the displaying of a message on an LED matrix must be controlled, with the rows being scanned sequentially at a rate greater than 40 MHz while sending out the column data at the same rate. This kind of control can be done by interfacing the LED matrix display with the microcontroller. Interfacing the LED Matrix Display with Microcontroller: Choosing a microcontroller for interfacing with the LED matrix display which is to be controlled is depends on the number of input and output pins needed for controlling all the LEDs in the given matrix display, the amount of current that each pin can source and sink, and the speed at which the microcontroller can send out control signals. With all these specifications, interfacing can be done for LED matrix display with a microcontroller. Tested Programming Code: A library needs to be downloaded and then to be installed. Go to Disk drive where your Arduino IDE is installed and then go to > Program Files>Arduino> Libraries> then Ctrl+V (Paste). https://github.com/riyas-org/max7219/tree/master/MaxMatrix https://github.com/riyas-org/max7219 : Main Link #include int DIN = 7; // DIN pin of MAX7219 module int CLK = 6; // CLK pin of MAX7219 module int CS = 5; // CS pin of MAX7219 module int maxInUse = 1; MaxMatrix m(DIN, CS, CLK, maxInUse); char A[] = {4, 8, B01111110, B00010001, B00010001, B01111110, }; char B[] = {4, 8, B01111111, B01001001, B01001001, B00110110, }; char smile01[] = {8, 8, B00111100, B01000010, B10010101, B10100001, B10100001, B10010101, B01000010, B00111100 }; char smile02[] = {8, 8, B00111100, B01000010, B10010101, B10010001, B10010001, B10010101, B01000010, B00111100 }; char smile03[] = {8, 8, B00111100, B01000010, B10100101, B10010001, B10010001, B10100101, B01000010, B00111100 }; void setup() { m.init(); // MAX7219 initialization m.setIntensity(8); // initial led matrix intensity, 0-15 } void loop() { // Seting the LEDs On or Off at x,y or row,column position m.setDot(6,2,true); delay(1000); m.setDot(6,3,true); delay(1000); m.clear(); // Clears the display for (int i=0; i<8; i++){ m.setDot(i,i,true); delay(300); } m.clear(); // Displaying the character at x,y (upper left corner of the character) m.writeSprite(2, 0, A); delay(1000); m.writeSprite(2, 0, B); delay(1000); m.writeSprite(0, 0, smile01); delay(1000); m.writeSprite(0, 0, smile02); delay(1000); m.writeSprite(0, 0, smile03); delay(1000); for (int i=0; i<8; i++){ m.shiftLeft(false,false); delay(300); } m.clear(); } Program Description: So first we need to include the MaxMatrix.h library, define the pins to which the module is connected, set how many modules we use and define the MaxMatrix object. For displaying characters, we need to define them in an array of characters or bytes, and here I have several examples. We can notice how the bits are forming the characters which are zeros and ones. In this case, they are rotated 90 degrees but the library example suggests using them in such a way so that would be easier later to implement the shift left custom function for scrolling a text. Precautions: 1. Double Check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check Whether the proper board is selected from Arduino IDE. 4. Ensure proper placement of sensor for correct working. Conclusion: You can successfully program different characters on a matrix display, this display can be combined with many more displays to get a larger display area. Output:: Reference URL GET IN TOUCH We'd love to hear from you Contact Us

Back Interfacing of Laser Diode with Arduino Uno. What is a Laser Diode? A laser diode , ( LD ), injection laser diode ( ILD ), or diode laser is a semiconductor device similar to a light-emitting diode in which the laser beam is created at the diode's junction.[1] Laser diodes are the most common type of lasers produced, with a wide range of uses that include fiber optic communications, barcode readers, laser pointers, CD/DVD/Blu-ray disc reading/recording, laser printing, laser scanning and light beam illumination. Material Required: Material Quantity Arduino Uno 1 Laser Diode 1 Jumper cables 2 Pinout Diagram: Circuit Diagram: Connect the Laser Diode with Arduino as follows: GND pin of Laser diode to GND of Arduino Signal pin of laser diode to digital pin 8 of Arduino Tested Programming Code: //we define the laser diode on digital pin 8 of Arduino. Int laser = 8 Void setup () { // we define the laser as output. pinMode (laser, OUTPUT); } Void loop () { //here we keep laser ON for half a seconds. digitalWrite (laser, HIGH); //wait for half a seconds . delay (500); // here we keep laser OFF for half a second. digitalWrite (laser, LOW); //wait for half a seconds. delay (500); } Precautions: 1. Double check the connections before powering on the circuit. 2. Don’t use loose jumper cables. 3. Check whether proper board is selected from Arduino IDE. 4. Ensure proper placement of laser diode for correct working. 5. Never look directly into a laser, it will cause eye damage. Conclusion: Once your sketch is running, you have to see the red spot on wall. Reference URL GET IN TOUCH We'd love to hear from you Contact Us