#Arduino relay light serial#
#Arduino relay light Bluetooth#

When the Bluetooth application's button turns ON, it sets the home light ON, and when the Bluetooth application's button turns OFF, it sets the home light OFF. The Arduino device read the input data and process it according to program uploaded inside it and generate the output to 4 Chanel Relay Module. The Bluetooth device receives the data from the app and sends it through TX pin of Bluetooth module to RX pin of Arduino.

#Arduino relay light serial#

The Android app sends the serial data to the connected Bluetooth Module HC-05 by clicking ON button. In this project, there are four main components used: Android smartphone Bluetooth application, Bluetooth transceiver, Arduino device, and 4 Channel Relay module. Working principle of Arduino-Bluetooth Module

AC 220v/120v home appliances or 9v Hi-Walt Battery.

In this project, we use Bluetooth Module HC-05, Arduino Device, 4 Channel Relay module, etc. In this project, we are going to build a home light controlling system using the Bluetooth network. Serial.Next → ← prev IoT project of controlling home light using Bluetooth module, Arduino device, and 4 Channel relay module Light() //execute the Light subroutine below If (distance < 13) //if the distance is less than 13 CM Int duration, distance //Define two intregers duration and distance to be used to save dataĭigitalWrite(trigPin, HIGH) //write a digital high to the trigpin to send out the pulseĭelayMicroseconds(500) //wait half a millisecondĭigitalWrite(trigPin, LOW) //turn off the trigpinĭuration = pulseIn(echoPin, HIGH) //measure the time using pulsein when the echo receives a signal set it to highĭistance = (duration/2) / 29.1 //distance is the duration devided by 2 becasue the signal traveled from the trigpin then back to the echo pin, then divide by 29.1 to convert to centimeters PinMode (bulb, OUTPUT) //set the bulb on pin 9 to output PinMode(echoPin, INPUT) //set the echopin to input PinMode(trigPin, OUTPUT) //set the trigpin to output Serial.begin (9600) //Start the serial monitor #define bulb 9 //Define the relay signal on pin 9 on the arduino #define trigPin 6 //Define the HC-SE04 triger on pin 6 on the arduino #define echoPin 5 //Define the HC-SE04 echo on pin 5 on the arduino When invoked, it activates the power relay pin, waits 15 seconds then it turns it off. And display the result on the serial monitor.

The next step is to verify the result that we got: If the result is less than 13cm, execute the light subroutine, if not then do nothing. When the wave returns I store the information in the 'duration' integer and activate the echo pin using the command pulseIn(echoPin, HIGH) Now we do some math to determine the distance, which is duration/2 then we divide this answer by 29.1 to get the result in centimeters. Then I tell the trigger to send a sound wave using the digitalWrite(trigPin, HIGH) command, then wait half a millisecond then I turn it off using the digitalWrite(trigPin, LOW) command. In the void setup, I start the serial monitor, define the Trigger and the Relay pins as outputs because they will output a result while the echo pin is defined as input because it will be waiting for information from the trigger pin.įirst I define two integers duration and distance to store the information gathered by the trigger. Initially I define three variables which are the physical pins from the HC-SR04 'trigger and echo' and the power relay. We will start with an open circuit = the light bulb is off, and when the relay receives a signal from the Arduino on the Signal PIN to close the circuit, the light bulb will turn on and we hear the distinctive 'Click' sound of the power relay activating.īefore plugging in the extension cord in the AC power outlet, lets work on the sketch and upload it to the Arduino first.įirst I will try to explain the sketch with words: NC = Naturally closed, which means that the circuit is closed and electricity is freely flowing. NO = Naturally open, which means that the circuit is open and no electricity is flowing through. Here you will take the cut section of the extension cord and screw in one end to the middle (no label) and the other end to the NO using a small screw driver. The screw terminal side of the power relay is labeled as follows: left NC, middle nothing, right NO

The - PIN is the ground and it is connected with a black jumper wire to the blue - rail on the breadboard. The + PIN is the 5V or VCC and it is connected with a red jumper wire to the red + rail on the breadboard. The S PIN is the signal and it is connected to PIN 9 on the Arduino

The three PINs are labeled as follows: s, +,. The songle srd-05vdc-sl-c power relay has three pins on one side and three screw terminals on the opposite side.