I got error to read data from ble MLDPTerminal

[konda01]

I got following error. "error":"read","message":"Unable to read on return"

I am using cordova bluetoothle plugin.

[gortok]

You're going To have to include your code that is causing this error and where in the code it happens. It will also help to know what device you're talking to.

[konda01]

The following code for used read data from RN4020 Bluetooth Low Energy (Microchip ).

/***************************************************************
   Read data from connected device.
*****************************************************************/
var readData = function() {

      var params = {
        address:'XX:XX:XX:XX',
        service: 'XXX-XXXX-XXXX',
        characteristic: 'XXX-XXXX-XXXX',
        timeout: 5000
      };

     console.log("Read : " + JSON.stringify(params));
     bluetoothle.read(readSuccess, readError, params);

};
var readSuccess= function(obj){
        console.log("Read Success : " + JSON.stringify(obj));
        if (obj.value && (!obj.type || obj.type == "data")) {
            var bytes = bluetoothle.encodedStringToBytes(obj.value);
            console.log("ASCII (" + bytes.length + "): " + bluetoothle.bytesToString(bytes));
            console.log("HEX (" + bytes.length + "): " + bluetoothle.bytesToHex(bytes));
        }

}
var readError = function(obj){
   console.log("Read Error : " + JSON.stringify(obj));
}

[konda01]

But I got the following error. "error":"read","message":"Unable to read on return".

And also i got the following warning.

THREAD WARNING: exec() call to BluetoothLePlugin.read blocked the main thread for 19ms. Plugin should use CordovaInterface.getThreadPool().

[gortok]

So it looks like you're not even using the wrapper; but another issue is that for you to read, you have to do service discovery first; Here's an example that uses the wrapper:

https://github.com/gortok/jewelapp/blob/master/app/scripts/device/jewelbot-service.js#L28

[konda01]

Hi Gortok, I did write the Bluetooth initialize, scan and connect after discovery the device then, I try to read the data that time i have problem

/* Bluetooth initialize checking. ***/ var initialize = function() { var params = { request: true, //restoreKey: "bluetooth-test-app" };

        console.log("Initialize : " + JSON.stringify(params));
        bluetoothle.initialize(initializeResult,params);
  };

  function initializeResult(obj){
    console.log("Initialize Success : " + JSON.stringify(obj));
    startScan();
  }

/* Scan Device ***/ var startScan = function() { var params = { services:[], allowDuplicates: false, scanTimeout: 5, };

    if (window.cordova) {
      params.scanMode = bluetoothle.SCAN_MODE_LOW_POWER;
      params.matchMode = bluetoothle.MATCH_MODE_STICKY;
      params.matchNum = bluetoothle.MATCH_NUM_ONE_ADVERTISEMENT;
      //params.callbackType = bluetoothle.CALLBACK_TYPE_FIRST_MATCH;
    }

    console.log("Start Scan : " + JSON.stringify(params));
    $('.blelist').empty();
    bluetoothle.startScan(startScanSuccess, startScanError, params);

};
var startScanSuccess = function(obj){
    console.log("Start Scan Auto Stop : " + JSON.stringify(obj));
    $('.blelist').append("<li><a href='#' onclick='connect(\""+obj.address+"\");'>"+obj.name+"</a></li>");
    $(document).trigger('create');
    $(".blelist").listview('refresh');
}
var startScanError = function(obj){
    console.log("Start Scan Auto Stop : " + JSON.stringify(obj));
}

/* Connect code ***/ var connect = function(address) { alert(address); var params = {address:address, timeout: 10000};

    console.log("Connect : " + JSON.stringify(params));
    bluetoothle.connect(connectSuccess, connectError, params);

  };
  var connectSuccess = function(obj){
     console.log("Connect Success : " + JSON.stringify(obj));
     alert("Connected");
     if( platformName== 'Android' ){
        //alert("android");
        discover();
     }else{
        //alert("ios");
        characteristics();
        descriptors();

     }

  }
  var connectError = function(obj){
    console.log("Connect Error : " + JSON.stringify(obj));
  }

/* Discover data. ***/ var discover = function() { var params = { address: 'XXXXXXXXXX', // "clearCache": true, timeout: 10000 };

    console.log("Discover : " + JSON.stringify(params));
    bluetoothle.discover(discoverSuccess, discoverError, params);

};

var discoverSuccess = function(obj){
    console.log("Discover Success : " + JSON.stringify(obj));
}
var discoverError = function(obj){
    console.log("Discover Error : " + JSON.stringify(obj));
}

[gortok]

So where does it error now and what is the error?

[konda01]

When i was read the data from ble device i got error. I got following error. "error":"read","message":"Unable to read on return"