javascript web_bluetooth.js

Posted 2021-05-04

    onButtonClick() {
        // Validate services UUID entered by user first.
        /*
        let optionalServices = document.querySelector('#optionalServices').value
          .split(/, ?/).map(s => s.startsWith('0x') ? parseInt(s) : s)
          .filter(s => s && BluetoothUUID.getService);
          */

        let optionalServices=['000018f0-0000-1000-8000-00805f9b34fb'];
      
        console.log('Requesting any Bluetooth Device...');
        navigator.bluetooth.requestDevice({
         // filters: [...] <- Prefer filters to save energy & show relevant devices.
            acceptAllDevices: true,
            optionalServices: optionalServices})
        .then(device => {
            console.log('Connecting to GATT Server...');
          return device.gatt.connect();
        })
        .then(server => {
          // Note that we could also get all services that match a specific UUID by
          // passing it to getPrimaryServices().
          console.log('Getting Services...');
          return server.getPrimaryServices();
        })
        .then(services => {
            console.log('Getting Characteristics...');
          let queue = Promise.resolve();
          services.forEach(service => {
            queue = queue.then(_ => service.getCharacteristics().then(characteristics => {
                console.log('> Service: ' + service.uuid);
              characteristics.forEach(characteristic => {
                console.log('>> Characteristic: ' + characteristic.uuid + ' ' +
                    getSupportedProperties(characteristic));
              });
            }));
          });
          return queue;
        })
        .catch(error => {
            console.log('Argh! ' + error);
        });
      }