Pair Classic Bluetooth from a Chrome App using chrome.bluetooth and chrome.bluetoothSocket APIs

Question

Ok so I'm trying to connect a bluetooth keyboard through a Chrome App. I was able to use this code and it has a status in the system tray as paired but I can't receive the data input from the keyboard. Example when I typed something in the text area using the bluetooth keyboard, it does not show anything in the text area.

This is how I used the API:

1. After the App is launched it calls the startDiscovery() method where it discovers the nearby bluetooth devices, in this case the bluetooth keyboard.
2. After the startDiscovery() method is finished, I am calling this function from a button click:

const getKnown = () => {
 chrome.bluetooth.getDevices((devices) => {

     for (var i = 0; i < devices.length; i++) {
         //Displaying device names 
         console.log(i + ": " + devices[i].name);
     }

     chrome.bluetoothSocket.create(function (createInfo) {

         chrome.bluetoothSocket.connect(createInfo.socketId,
             address, service, () => {
                 if (chrome.runtime.lastError) {
                     console.log("getKnown Connection failed: " + chrome.runtime.lastError.message);
                 } else {
                     console.log(`successfully connected on device: ${address}`);
                 }
             });

         chrome.bluetoothSocket.onAccept.addListener(function (acceptInfo) {
             console.log('onAccept...');
             if (acceptInfo.socketId != createInfo.socketId)
                 return;

         });
     });
 });
};

getKnownButton.onclick = () => getKnown();

The only problem I need to solve is how to get the input data from the keyboard. I'm not really sure what's wrong with the code. How can I get the input data from the keyboard?

Answer 1

Just to step back a bit from your question, as it is a bluetooth keyboard device, after it pairs and gets enumerated as a keyboard device by the OS, there are other APIs like keyboard (https://developer.mozilla.org/en-US/docs/Web/API/Keyboard_API) or even HID API (https://developer.mozilla.org/en-US/docs/Web/API/WebHID_API) you could use and they are more straightforward

Back to the sample you provided, it seems you don't have the part that receives the input data from the keyboard.

You probably need to use https://developer.chrome.com/docs/extensions/reference/bluetoothSocket/#event-onReceive for receiving the input data from the bluetooth keyboard. (so as listenUsingRfcomm or listenUsingL2cap according to your device)

Here is a tutorial page for your reference. https://sunnyzhou-1024.github.io/chrome-extension-docs/apps/app_bluetooth.html#using_rfcomm

Please note that https://developer.chrome.com/docs/extensions/reference/bluetoothSocket/ are being deprecated and it is strongly recommended not to use it or be prepared to migrate from it in the future. See more details in :

• https://blog.chromium.org/2020/08/changes-to-chrome-app-support-timeline.html
• https://blog.chromium.org/2021/10/extending-chrome-app-support-on-chrome.html

serial-over-bluetooth is a proposal to cover Bluetooth Classic RFCOMM after deprecating the Chrome App API.