Avatar for Q_NErk


Member since Apr 2023 • Last active Apr 2023
  • 1 conversations

Most recent activity

  • in Bangle.js
    Avatar for Q_NErk

    I'm not a bot (I know, all bot can say it :))
    I'm not familiar with JS, that why I'm trying to solve it anyhow by (like You said) c in Arduino envoirment. This is my first tries with BT/BLE.

  • in Bangle.js
    Avatar for Q_NErk

    I passed it this way. I have installed btadv for begining and after this I've tried to set esp32 bluetooth client:

     * A BLE client example that is rich in capabilities.
     * There is a lot new capabilities implemented.
     * author unknown
     * updated by chegewara
    [#include](http://forum.espruino.com/sea­rch/?q=%23include) "BLEDevice.h"
    //#include "BLEScan.h"
    // The remote service we wish to connect to.
    static BLEUUID serviceUUID("0000180d-0000-1000-8000-008­05f9b34fb");
    // The characteristic of the remote service we are interested in.
    static BLEUUID    charUUID("0000180d-0000-1000-8000-00805f­9b34fb");
    static boolean doConnect = false;
    static boolean connected = false;
    static boolean doScan = false;
    static BLERemoteCharacteristic* pRemoteCharacteristic;
    static BLEAdvertisedDevice* myDevice;
    static void notifyCallback(
      BLERemoteCharacteristic* pBLERemoteCharacteristic,
      uint8_t* pData,
      size_t length,
      bool isNotify) {
        Serial.print("Notify callback for characteristic ");
        Serial.print(" of data length ");
        Serial.print("data: ");
    class MyClientCallback : public BLEClientCallbacks {
      void onConnect(BLEClient* pclient) {
      void onDisconnect(BLEClient* pclient) {
        connected = false;
    bool connectToServer() {
        Serial.print("Forming a connection to ");
        BLEClient*  pClient  = BLEDevice::createClient();
        Serial.println(" - Created client");
        pClient->setClientCallbacks(new MyClientCallback());
        // Connect to the remove BLE Server.
        pClient->connect(myDevice);  // if you pass BLEAdvertisedDevice instead of address, it will be recognized type of peer device address (public or private)
        Serial.println(" - Connected to server");
        pClient->setMTU(517); //set client to request maximum MTU from server (default is 23 otherwise)
        // Obtain a reference to the service we are after in the remote BLE server.
        BLERemoteService* pRemoteService = pClient->getService(serviceUUID);
        if (pRemoteService == nullptr) {
          Serial.print("Failed to find our service UUID: ");
          return false;
        Serial.println(" - Found our service");
        // Obtain a reference to the characteristic in the service of the remote BLE server.
        pRemoteCharacteristic = pRemoteService->getCharacteristic(charUU­ID);
        if (pRemoteCharacteristic == nullptr) {
          Serial.print("Failed to find our characteristic UUID: ");
          return false;
        Serial.println(" - Found our characteristic");
        // Read the value of the characteristic.
        if(pRemoteCharacteristic->canRead()) {
          std::string value = pRemoteCharacteristic->readValue();
          Serial.print("The characteristic value was: ");
        connected = true;
        return true;
     * Scan for BLE servers and find the first one that advertises the service we are looking for.
    class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
       * Called for each advertising BLE server.
      void onResult(BLEAdvertisedDevice advertisedDevice) {
        Serial.print("BLE Advertised Device found: ");
        // We have found a device, let us now see if it contains the service we are looking for.
        if (advertisedDevice.haveServiceUUID() && advertisedDevice.isAdvertisingService(se­rviceUUID)) {
          myDevice = new BLEAdvertisedDevice(advertisedDevice);
          doConnect = true;
          doScan = true;
        } // Found our server
      } // onResult
    }; // MyAdvertisedDeviceCallbacks
    void setup() {
      Serial.println("Starting Arduino BLE Client application...");
      // Retrieve a Scanner and set the callback we want to use to be informed when we
      // have detected a new device.  Specify that we want active scanning and start the
      // scan to run for 5 seconds.
      BLEScan* pBLEScan = BLEDevice::getScan();
      pBLEScan->setAdvertisedDeviceCallbacks(n­ew MyAdvertisedDeviceCallbacks());
      pBLEScan->start(5, false);
    } // End of setup.
    // This is the Arduino main loop function.
    void loop() {
      // If the flag "doConnect" is true then we have scanned for and found the desired
      // BLE Server with which we wish to connect.  Now we connect to it.  Once we are 
      // connected we set the connected flag to be true.
      if (doConnect == true) {
        if (connectToServer()) {
          Serial.println("We are now connected to the BLE Server.");
        } else {
          Serial.println("We have failed to connect to the server; there is nothin more we will do.");
        doConnect = false;
      // If we are connected to a peer BLE Server, update the characteristic each time we are reached
      // with the current time since boot.
      if (connected) {
        String newValue = "Time since boot: " + String(millis()/1000);
        Serial.println("Setting new characteristic value to \"" + newValue + "\"");
        // Set the characteristic's value to be the array of bytes that is actually a string.
        pRemoteCharacteristic->writeValue(newVal­ue.c_str(), newValue.length());
      }else if(doScan){
        BLEDevice::getScan()->start(0);  // this is just example to start scan after disconnect, most likely there is better way to do it in arduino
      delay(1000); // Delay a second between loops.
    } // End of loop

    And I'm receiving:

    BLE Advertised Device found: Name: Bangle.js e4e1, Address: f0:40:5d:1d:e4:e1, serviceUUID: 0000180d-0000-1000-8000-00805f9b34fb, serviceUUID: 0000181a-0000-1000-8000-00805f9b34fb, serviceUUID: 00001819-0000-1000-8000-00805f9b34fb
    Forming a connection to f0:40:5d:1d:e4:e1
     - Created client
     - Connected to server
     - Found our service
    Failed to find our characteristic UUID: 0000180d-0000-1000-8000-00805f9b34fb
    We have failed to connect to the server; there is nothin more we will do.

    What I'm doing wrong?

  • in Bangle.js
    Avatar for Q_NErk

    It can be peer to peer or it can be brodacasted by bangle.js via BT. Yes, ESP32 will collect data. The best will be from multiple Bangle.js

  • in Bangle.js
    Avatar for Q_NErk

    I have one question: how to read values from bangle.js by device like esp32? I want to use it for my project will external display values from wristband.
    I guess that it will be needed to connect to specified bangle.js and then somehow use data similar way to js.