Web Bluetooth / Manufacturer Data Filter (Async Await) Sample

Available in Chrome 92+ | View on GitHub | Browse Samples

The Web Bluetooth API lets websites discover and communicate with devices over the Bluetooth 4 wireless standard using the Generic Attribute Profile (GATT). It is currently partially implemented in Android M, Chrome OS, Mac, and Windows 10.

This sample illustrates the use of the Web Bluetooth API to retrieve basic device information from a nearby Bluetooth Low Energy Device that matches manufacturer specific data. You may want to check out the Manufacturer Data Filter (Promises) sample.

Manufacturer Data:

Live Output











  
    
      
    
  

  
    
JavaScript Snippet

  

  
    
async function onButtonClick() {
  let manufacturerData = {};

  const filterCompanyIdentifier = document.querySelector('#companyIdentifier').value;
  if (filterCompanyIdentifier) {
    manufacturerData.companyIdentifier = parseInt(filterCompanyIdentifier);
  }
  
  const filterDataPrefix = document.querySelector('#dataPrefix').value;
  if (filterDataPrefix) {
    manufacturerData.dataPrefix = hexStringToUint8Array(filterDataPrefix);
  }

  const filterMask = document.querySelector('#mask').value;
  if (filterMask) {
    manufacturerData.mask = hexStringToUint8Array(filterMask);
  }

  const options = { filters: [{ manufacturerData: [manufacturerData] }] };

  try {
    log('Requesting Bluetooth Device...');
    log('with ' + JSON.stringify(options));
    const device = await navigator.bluetooth.requestDevice(options);

    log('> Name:             ' + device.name);
    log('> Id:               ' + device.id);
    log('> Connected:        ' + device.gatt.connected);
  } catch(error)  {
    log('Argh! ' + error);
  }
}

/* Utils */

function hexStringToUint8Array(hexString) {
  if (hexString.length % 2 != 0) {
    throw "Invalid hexString";
  }
  let arrayBuffer = new Uint8Array(hexString.length / 2);
  for (let i = 0; i < hexString.length; i += 2) {
    const byteValue = parseInt(hexString.substr(i, 2), 16);
    if (byteValue == NaN) {
      throw "Invalid hexString";
    }
    arrayBuffer[i / 2] = byteValue;
  }
  return arrayBuffer;
}