microbit-web-bluetooth/src/services/device-information.ts

Web Bluetooth library for micro:bit

/*
* micro:bit Web Bluetooth
* Copyright (c) 2019 Rob Moran
*
* The MIT License (MIT)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the 'Software'), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/

import { ServiceHelper } from '../service-helper';

/**
 * @hidden
 */
export enum DeviceInformationCharacteristic {
    modelNumber = '00002a24-0000-1000-8000-00805f9b34fb',
    serialNumber = '00002a25-0000-1000-8000-00805f9b34fb',
    firmwareRevision = '00002a26-0000-1000-8000-00805f9b34fb',
    hardwareRevision = '00002a27-0000-1000-8000-00805f9b34fb',
    manufacturer = '00002a29-0000-1000-8000-00805f9b34fb'
}

/**
 * Device information structure
 */
export interface DeviceInformation {
    /**
     * Model Number
     */
    modelNumber?: string;
    /**
     * Serial Number
     */
    serialNumber?: string;
    /**
     * Firmware Revision
     */
    firmwareRevision?: string;
    /**
     * Hardware Revision
     */
    hardwareRevision?: string;
    /**
     * Manufacturer Name
     */
    manufacturer?: string;
}

/**
 * Device Information Service
 */
export class DeviceInformationService {

    /**
     * @hidden
     */
    public static uuid = '0000180a-0000-1000-8000-00805f9b34fb';

    /**
     * @hidden
     */
    public static async create(service: BluetoothRemoteGATTService): Promise<DeviceInformationService> {
        return new DeviceInformationService(service);
    }

    private helper: ServiceHelper;

    /**
     * @hidden
     */
    constructor(service: BluetoothRemoteGATTService) {
        this.helper = new ServiceHelper(service);
    }

    /**
     * Read device information
     */
    public async readDeviceInformation(): Promise<DeviceInformation> {
        const info: DeviceInformation = {};

        const modelNumber = await this.readStringCharacteristic(DeviceInformationCharacteristic.modelNumber);
        if (modelNumber) info.modelNumber = modelNumber;

        const serialNumber = await this.readStringCharacteristic(DeviceInformationCharacteristic.serialNumber);
        if (serialNumber) info.serialNumber = serialNumber;

        const firmwareRevision = await this.readStringCharacteristic(DeviceInformationCharacteristic.firmwareRevision);
        if (firmwareRevision) info.firmwareRevision = firmwareRevision;

        const hardwareRevision = await this.readStringCharacteristic(DeviceInformationCharacteristic.hardwareRevision);
        if (hardwareRevision) info.hardwareRevision = hardwareRevision;

        const manufacturer = await this.readStringCharacteristic(DeviceInformationCharacteristic.manufacturer);
        if (manufacturer) info.manufacturer = manufacturer;

        return info;
    }

    private async readStringCharacteristic(uuid: BluetoothCharacteristicUUID): Promise<string | undefined> {
        try {
            const view = await this.helper.getCharacteristicValue(uuid);
            const decoder = new TextDecoder();
            return decoder.decode(view.buffer);
        } catch (_e) {
            return undefined;
        }
    }
}