About the Application
You can expand the functionality of the prev app if you add a hardware button control. Pressing the button will also toggle the state of the GPIO line (LED, relay,…) which is reflected in the LED state displayed in the browser window.
What you need
Besides the hardware used in the prev app you will also need:
-
1 x Tibbit #38 (push button)
-
1 x Tibbit #00_3 (2 direct I/O Lines with 5V and Ground)
GitHub Repository
Name: tps-gpio-tutorials
Repository page: https://github.com/tibbotech/tps-gpio-tutorials
Clone URL: https://github.com/tibbotech/tps-gpio-tutorials.git
Updated At: Mon Oct 10 2016
Node.js Application
Add the following code to server.js:
server.
...
var button = gpio.init("S11A");
var wasButtonPressed = false;
button.setDirection('input');
setInterval(function(){
// If button is just released...
if(button.getValue() === 1 && wasButtonPressed === true){
wasButtonPressed = false;
// ...reads the LED state...
var ledState = led.getValue();
//...inverses it...
if(ledState === 1){
ledState = 0
}else{
ledState = 1;
}
//...writes...
led.setValue(ledState);
//...and submits to the web app if connected
if(clients !== undefined){
clients.emit('tps:state:changed', ledState);
}
}else if(button.getValue() === 0){
// If button is pressed
wasButtonPressed = true;
}
},100);
...