fivdi/onoff

Raspberry Pi GPIO control in electron App

lakshanthad opened this issue · 8 comments

lakshanthad commented

I have created a simple app that can control the GPIO pins on the Raspberry Pi with a simple button press. However, when I press the button, there is no response from the GPIO pins (here connected to GPIO 24). Also, I have already installed the onoff module from npm install onoff. When I create a simple javascript file with only GPIO control and run node <file_name>.js, it runs successfully. But when I try to integrate into electron, it stops working. Please check the following code. Help would be appreciated.

index.html

<!DOCTYPE html>
<html>
    <body>
        <h1>GPIO Control</h1>
        <button id="Btn" class="button is-primary">LED ON</button>
        <script src="./render.js"></script>
    </body>
</html>

main.js

const { app, BrowserWindow } = require('electron')
const path = require('path')

function createWindow () {
  const mainWindow = new BrowserWindow({
    width: 800,
    height: 600,
    webPreferences: {
        nodeIntegration: true
      }
  })

  mainWindow.loadFile('index.html')
}

app.whenReady().then(() => {
  createWindow()

  app.on('activate', function () {
    if (BrowserWindow.getAllWindows().length === 0) createWindow()
  })
})

app.on('window-all-closed', function () {
  if (process.platform !== 'darwin') app.quit()
})

render.js

var Gpio = require('onoff').Gpio; 
var LED = new Gpio(24, 'out');

const Btn = document.getElementById("Btn");
Btn.onclick = function() {
  myFunction()
};

function myFunction() {
  LED.writeSync(1);
}
fivdi commented

I'm afraid I'm not familiar with Electron and can't provide much help. Are error messages displayed when the application is run?

fivdi commented

Duplicate of atom/atom#22638

onoff depends on a native Node module called epoll. Special steps need to be taken when installing native Node modules like epoll with Electron. For additional information see here.

If these special steps are not taken into account, errors complaining about incorrect NODE_MODULE_VERSION numbers like the errors shown here can occur.

@lakshanthad Is your application showing NODE_MODULE_VERSION errors or other errors?

leerlemoniii commented
lakshanthad commented

Hello. Thank you all for the replies. I have now made it work using ipcMain and ipcRenderer modules. Not sure whether there is an easy way to do this

fivdi commented

Thank you for the feedback. I guess if it's working now the issue can be closed.

NathanJ4620 commented

the ipcMain and ipcRenderer are the only ways to communicate between electron and an external Node instance. This functionality is to help maintain security on the host device when creating a shipped application.

TheGrateMartian commented

I am trying to do the same. @lakshanthad Can you share please show/share what you did to get it workin?