Arduino Project
Touch Toggle
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Course Introduction
This Arduino project uses a touch sensor and a traffic light LED module to simulate a simple traffic light system. Each time the touch sensor is pressed, the LEDs switch in sequence from red to yellow to green. This example demonstrates how to use a touch sensor as an input trigger to control multiple LEDs in a sequence.
Note
If this is your first time working with an Arduino project, we recommend downloading and reviewing the basic materials first.
1.1 Install Arduino IDE(Important)
1.2 Introduce of Arduino IDE
Required Components
In this project, we need the following components:
Wiring
Common Connections:
Traffic light LED
R: Connect to 7 on the Arduino.
Y: Connect to 8 on the Arduino.
G: Connect to 9 on the Arduino.
GND: Connect to GND on the Arduino.
Touch Sensor Module
SIG: Connect to 2 on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s red power bus.
Writing the Code
Note
1.You can copy this code into Arduino IDE.
2.Don’t forget to select the board(Arduino UNO R4 Minima/WIFI) and the correct port before clicking the Upload button.
/*
The code controls a traffic light LED module with a touch sensor.
Once the touch sensor is activated, the LEDs cycle through turning
on in sequence: Red -> Yellow -> Green.
Board: Arduino Uno R4 (or R3)
Component: Touch Sensor Module and Traffic Light Module
*/
// Define pins for touch sensor and LEDs
const int touchSensorPin = 2; // touch sensor pin
const int rledPin = 7; // red LED pin
const int yledPin = 8; // yellow LED pin
const int gledPin = 9; // green LED pin
int lastTouchState; // the previous state of touch sensor
int currentTouchState; // the current state of touch sensor
int currentLED = 0; // current LED 0->Red, 1->Yellow, 2->Green
void setup() {
Serial.begin(9600); // initialize serial
pinMode(touchSensorPin, INPUT); // configure touch sensor pin as input
// set LED pins as outputs
pinMode(rledPin, OUTPUT);
pinMode(yledPin, OUTPUT);
pinMode(gledPin, OUTPUT);
currentTouchState = digitalRead(touchSensorPin);
}
void loop() {
lastTouchState = currentTouchState; // save the last state
currentTouchState = digitalRead(touchSensorPin); // read new state
// check if the touch sensor was just touched
if (lastTouchState == LOW && currentTouchState == HIGH) {
Serial.println("The sensor is touched");
turnAllLEDsOff(); // Turn off all LEDs
// switch on the next LED in sequence
switch (currentLED) {
case 0:
digitalWrite(rledPin, HIGH);
currentLED = 1;
break;
case 1:
digitalWrite(yledPin, HIGH);
currentLED = 2;
break;
case 2:
digitalWrite(gledPin, HIGH);
currentLED = 0;
break;
}
}
}
// function to turn off all LEDs
void turnAllLEDsOff() {
digitalWrite(rledPin, LOW);
digitalWrite(yledPin, LOW);
digitalWrite(gledPin, LOW);
}