This code is used to blink an LED connected to a GPIO pin.
This code requires the onoff package to be installed.
The LED is connected to GPIO pin 4, and is set to output mode.
The blinkLED function is called every 250ms, which turns the LED on and off. The LED blinking can be stopped by calling the endBlink function. This will stop the blinking and turn the LED off.
| var Gpio = require('onoff').Gpio; //include onoff to interact with the GPIO | |
| var LED = new Gpio(4, 'out'); //use GPIO pin 4, and specify that it is output | |
| var blinkInterval = setInterval(blinkLED, 250); //run the blinkLED function every 250ms | |
| function blinkLED() { //function to start blinking | |
| if (LED.readSync() === 0) { //check the pin state, if the state is 0 (or off) | |
| LED.writeSync(1); //set pin state to 1 (turn LED on) | |
| } else { | |
| LED.writeSync(0); //set pin state to 0 (turn LED off) | |
| } | |
| } | |
| function endBlink() { //function to stop blinking | |
| clearInterval(blinkInterval); // Stop blink intervals | |
| LED.writeSync(0); // Turn LED off | |
| LED.unexport(); // Unexport GPIO to free resources | |
| } | |
| setTimeout(endBlink, 5000); //stop blinking after 5 seconds |