zwack/lib/cps/cycling-power-service.js

Simulate an indoor bicycle trainer with BLE (Bluetooth Low Energy)

const Bleno = require('@abandonware/bleno');

const CyclingPowerMeasurementCharacteristic = require('./cycling-power-measurement-characteristic');
const StaticReadCharacteristic = require('../read-characteristic');

// https://developer.bluetooth.org/gatt/services/Pages/ServiceViewer.aspx?u=org.bluetooth.service.cycling_power.xml
class CyclingPowerService extends Bleno.PrimaryService {
    constructor() {
        let powerMeasurement = new CyclingPowerMeasurementCharacteristic();
        super({
            uuid: '1818',
            characteristics: [
                powerMeasurement,
                new StaticReadCharacteristic('2A65', 'Cycling Power Feature', [0x08, 0, 0, 0]), // 0x08 - crank revolutions
                new StaticReadCharacteristic('2A5D', 'Sensor Location', [13]), // 13 = rear hub
            ],
        });

        this.powerMeasurement = powerMeasurement;
    }

    notify(event) {
        this.powerMeasurement.notify(event);
        return this.RESULT_SUCCESS;
    }
}

module.exports = CyclingPowerService;