BluetoothDevice x ChromeBrowser

BleServer.cpp

#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEServer.h>
#include <BLE2902.h>

#define SERVICE_UUID        "xxxxx"
#define CHARACTERISTIC_UUID "yyyyy"
#define DEVICE_NAME "BLE_Controller"

using namespace std;

BLEServer *pServer = NULL;
BLEService *pService = NULL;
BLECharacteristic *pCharacteristic = NULL;

int counter = 0;

// Send to browser
void sendMsg(const string msg){
    if(!pServer && !pService) return;
    pCharacteristic->setValue(msg.c_str());
    pCharacteristic->notify();
    Serial.println(msg.c_str());
}

// Receive from browser
class BLECallback: public BLECharacteristicCallbacks{
    void onWrite(BLECharacteristic *characteristic){
        string value = characteristic->getValue();
        if (0 < value.length()) Serial.println(value.c_str());
    }
};

void setup(){
    Serial.begin(115200);
    Serial.println("Starting BLE!!");
    Serial.println(DEVICE_NAME);
  
    // BLEDevice
    BLEDevice::init(DEVICE_NAME);
    pServer = BLEDevice::createServer();
    pService = pServer->createService(SERVICE_UUID);
    pCharacteristic = pService->createCharacteristic(CHARACTERISTIC_UUID, 
                                                    BLECharacteristic::PROPERTY_READ | 
                                                    BLECharacteristic::PROPERTY_WRITE |
                                                    BLECharacteristic::PROPERTY_NOTIFY |
                                                    BLECharacteristic::PROPERTY_INDICATE);
    pCharacteristic->addDescriptor(new BLE2902());// Very important!!(using notification)
    pCharacteristic->setCallbacks(new BLECallback());// Callback
    //pCharacteristic->setValue("Hello World says Neil");
    //pCharacteristic->notify();
  
    // Start
    pService->start();
  
    // BLEAdvertising
    BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
    pAdvertising->addServiceUUID(SERVICE_UUID);
    pAdvertising->setScanResponse(true);
    pAdvertising->setMinPreferred(0x06);
    pAdvertising->setMinPreferred(0x12);
    BLEDevice::startAdvertising();
    Serial.println("Characteristic defined!!");
}

void loop(){
    Serial.println("BLE_Controller working...");
    char msg[24];
    sprintf(msg, "Hello, BLE:%01d", counter++);
    sendMsg(msg);// Send
    delay(2000);
}

main.js

"use strict";

//==========
// BluetoothDevice <-> Chrome連携

// GoogleChromeとBLE端末との連携手順
//	1, GoogleChromeで次のアドレスを入力
//		chrome://flags/#enable-experimental-web-platform-features
//	2, Experimental Web Platform features
//		Enabled
//	3, Console画面で次の命令を入力(接続可能デバイス検索)
//		navigator.bluetooth.requestDevice({acceptAllDevices: true})
//  4, トラブルシューティング
//		4-1, ブラウザの更新からConnectでの再接続が出来ない
//			AtomLiteの再起動(Upload, USBケーブルの抜き差し)

// BluetoothDeviceと合わせる事
const UUID_SERVICE        = "xxxxx";
const UUID_CHARACTERISTIC = "yyyyy";
const DEVICE_NAME         = "BLE_Controller";

const options = {
	acceptAllDevices: false,
	filters: [{namePrefix: DEVICE_NAME}],
	optionalServices: [UUID_SERVICE]
}

let bleDevice = null;
let characteristic = null;

let counter = 0;

// Window
window.onload = (e)=>{
	console.log("onload");

	$("#btn_connect").click(()=>{
		connect();
	});

	$("#btn_send").click(()=>{
		sendMsg("Hello, Browser:" + counter++);
	});
}

async function connect(){
	emptyInfo();

	// Bluetooth
	navigator.bluetooth.requestDevice(options).then(device=>{
		console.log("Device:", device);
		addInfo("Device", device.id);
		bleDevice = device;
		bleDevice.addEventListener("gattserverdisconnected", onDisconnected);
		return device.gatt.connect();
	}).then(server=>{
		console.log("Server:", server);
		addInfo("Server", server.device.name);
		return server.getPrimaryService(UUID_SERVICE);
	}).then(service=>{
		console.log("Service:", service);
		addInfo("Service", service.uuid);
		return service.getCharacteristic(UUID_CHARACTERISTIC);
	}).then(chara=>{
		console.log("Characteristic:", chara);
		addInfo("Characteristic", chara.uuid);
		characteristic = chara;
		return chara.startNotifications().then(chara=>{
			chara.addEventListener("characteristicvaluechanged", onValueChanged);
		});
	}).catch(error=>{
		console.log(error);
		addInfo(error);
	});
}

function onDisconnected(event){
	const name = event.target.name;
	console.log("Disconnected:", name);
	addInfo("Disconnected", name);
	bleDevice.removeEventListener("gattserverdisconnected", onDisconnected);
	characteristic.removeEventListener("characteristicvaluechanged", onValueChanged);
}

function onValueChanged(event){
	const value = event.target.value;
	const decoder = new TextDecoder("utf-8");
	const str = decoder.decode(value);
	console.log("Value:", str);
	addInfo("Value", str);
}

function sendMsg(msg){
	if(!bleDevice || !bleDevice.gatt.connected) return;
	if(!characteristic) return;
	console.log("sendMsg:", msg);
	const value = new TextEncoder().encode(msg);
	characteristic.writeValue(value);// Write
}

function emptyInfo(){
	$("#info").empty();
}

function addInfo(tag, msg){
	$("#info").prepend("<li>" + tag + ":" + msg + "</li>");
}