I have a problem with testing my application on Android platform. I have functional application on x86 architecture. This application can connect to Bluetooth LowEnergy device and communicate with it. BT device is HM-10 module - serial line.
But when I try the same application, but just compiled for Android, I'm not able to receive any data back. On the other hand I can see on remote device that all data from mobile terminal are sent.
What I suspect as a possible problem is that signal QLowEnergyService::characteristicChanged is not emitted. In the documentation http://doc.qt.io/qt-5/qlowenergyservice.html is written that you should register for changes, but at least on PC it is done automatically somehow.
Would anyone please help me ?
You have to do some magic
QLowEnergyDescriptor notification = _characteristic.descriptor(
QBluetoothUuid::ClientCharacteristicConfiguration);
if (!notification.isValid()) {
qDebug() >> "QLowEnergyDescriptor not valid";
}
connect(_service, &QLowEnergyService::characteristicChanged, this,
&Device::onCharacteristicChanged);
_service->writeDescriptor(notification, QByteArray::fromHex("0100"));
Related
Situation:
VS 2022, 17.0.4
Maui App,
net6.0-android
AndroidManifest.xml contains also:
android.permission.INTERNET
android.permission.CHANGE_NETWORK_STATE
android.permission.ACCESS_WIFI_STATE
android.permission.CHANGE_WIFI_MULTICAST_STATE
android.permission.CHANGE_WIFI_STATE
Connected mobile Phone:
Samsung SM-G960F (Android 10.0 - API 29)
OS: Windows 11, latest patch.
All firewalls are down (for testing purpose only!)
While debugging the develop computer is only connected to a Wifi network; computers ethernet card is disabled.
Mobile phone is connected to this dev computer via USB cable (to be able to debug) and to the same Wifi network as the computer.
App starts and works fine, app can be debugged. No issue at all - except:
After the application is fully initialized and ready to accept user interactions -> Click on button -> Desired method is called -> Code is worked out -> The code should make a simple UDP call but it does not (or the packet does not reach the UDP listener due to missing configuration?).
The UDP receiver works fine and is capable to receive UDP packets.
My mobile phone and the UDP receiver app are using the same port.
I read/found already that in the previous cross-platform framework, means “Xamarin (Android SDK 12)”, some permissions must be set (I did, see above) and that the multicastlock must be set over the WifiManager …
I tried this in my MAUI app. But could not find anything guiding me nor figured it out by myself.
My MAUI sending code:
var dataToBeSend = "What ever ...";
var data = Encoding.UTF8.GetBytes(dataToBeSend);
var UdpClient = new UdpClient();
// UdpClient.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, true);
UdpClient.ExclusiveAddressUse = false;
UdpClient.EnableBroadcast = true;
// UdpClient.Client.Bind(new IPEndPoint(IPAddress.Parse("255.255.255.255"), BroadcastPort));
// UdpClient.Client.Bind(new IPEndPoint(IPAddress.Any, BroadcastPort));
UdpClient.Send(data, data.Length, "255.255.255.255", BroadcastPort);
As said: very easy and straight forward.
Notice that I also tried binding UDP code …
So please can someone be so kind to guide me or give me a hint?
Thank you very much in advance!
ANSWER:
After two days I found a solution - and would like to share it because may be it helps someone else.
The code to make the UDP call msut be placed in a THREAD (not task!)
codesnippet:
var communication = new Communication();
var udpThread = new Thread(new ThreadStart(communication.FireUDPCall));
udpThread.Start();
The firewalls can stay turned on / active!
I'm having issues when trying to use bluetooth on my project. On previous version I used the HC-05 module for bluetooth and it gives me a simple serial connection right after any device connects. Now the project evolved and we opted on using SIM800H because it gives us GSM+Bluetooth.
When I connect any android device it gives me some profiles but never SPP. I can pair normally but when using any SPP server app (https://stackoverflow.com/a/4037619/2637661) I can never send or get data from my device. If I start the connection from the Android app, it says that it's connecting while the SIM800 gives me the URC and I respond:
+BTCONNECTING: "34:c7:31:aa:37:5b","SPP"
AT+BTACPT=1
OK
+BTCONNECT: 1,"Android",34:c7:31:aa:37:5b,"SPP"
But it stays on server mode and I can't use the commands AT+BTSPPSEND or AT+BTSPPGET, as the documentation says.
On the other hand, if I start the connection from my device just like the docs say:
AT+BTCONNECT=1,4 // Device is 1 and SPP profile is 4
OK
AT+BTSPPSEND
>I type anything here + ctrl+z
SEND FAIL
and get nothing on the Android side.
Plus in both cases the connection drops after something like 30s and I can't reestablish it unless I turn the SIM800H off and on again.
Got no success using the APP mode either (sending the string "SIMCOMSPPFORAPP" right after connection succeeds for transparent communication).
The SIM800H firmware version is
AT+CGMR
Revision:1309B07SIM800H32_BT
and I tried using the following apps
Bluetooth Terminal
Bluetooth spp pro
BlueSPP
The GSM side works flawlessly and I can send/receive TCP messages everytime I try.
Does anyone have any kind of experience using this module? Thanks for reading!
UPDATE:
I'm using a simple sketch in order to talk with the module's serial, don't know if it's relevant but here it goes.
#define SIM800_POWER 23
void setup() {
Serial.begin(9600);
Serial1.begin(19200);
Serial.print("Setting all up");
pinMode(SIM800_POWER, OUTPUT);
Serial.print(".");
delay(500);
digitalWrite(SIM800_POWER, HIGH);
Serial.print(".");
Serial.println("OK");
}
void loop() {
if(Serial1.available()){
Serial.write(Serial1.read());
}
if(Serial.available()){
Serial1.write(Serial.read());
}
}
And what I get after trying Andrii's answer:
Setting all up..OK
AT
OK
AT
OK
AT
OK
AT+BTPOWER=0
OK
AT+BTPOWER=1
OK
AT+BTCONNECT=1,4
OK
+BTCONNECT: 1,"Will",d4:87:d8:77:37:0b,"SPP"
AT+BTSTATUS?
+BTSTATUS: 5
P: 1,"Will",d4:87:d8:77:37:0b
C: 1,"Will",d4:87:d8:77:37:0b,"SPP"
OK
AT+BTSPPSEND
> SIMCOMSPPFORAPP
SEND FAIL
Seems AT+BTSPPSEND without any parameters is only for AT-command send from client (your SIM800H) to server (other SIM800, not your Android device unless your Android device implements AT-command support). For data sending you should use AT+BTSPPSEND and after receiving > symbol send SIMCOMSPPFORAPP keyword and then, after receiving SEND OK response send command AT+BTSPPSEND=<LENGTH_OF_YOUR_DATA> and then, after receiving > symbol, send your data until Ctrl+Z code e.g.:
AT+BTSPPSEND
> SIMCOMSPPFORAPP
SEND OK
AT+BTSPPSEND=5
> HELLO
SEND OK
^Z
where HELLO - is your data, and 5 in AT+BTSPPSEND=5 is length of HELLO string. Details in SIM800H_BT_Application_Note.
UPDATE
Selected by bold small, but important part of answer (thanks to hlovdal)
I am new to android studios and I have the task to develop an app which transfers data from an app (Acceleration sensor data - i have created this app already which shows the data) to matlab (on the pc).
I don't really know how I should do this. I've experimented a bit with bluetooth apps, but I don't have a clue how to connect to Matlab.
I would be greatful for your help.
Thanks in advance,
Annika
Unfortunately I can not speak to the android side of things, but MatLab can connect to generic devices with the UART interface, which is fairly low level.
The process with some microprocessors that I am using is to connect the device to the PC, and then note the Outgoing com port.
(In windows 10, these can be found in Bluetooth settings -> More Bluetooth options)
Then you can use
s = serial('COM<what you found in settings>');
s.Baudrate=115200;
s.InputBufferSize = 100;
fopen(s{i});
serials = instrfindall;
to open an connection. The critical command is serial, the other parameters depend on your device/ configuration. Sometimes there can be issues, in which case one options is to build a loop that tries again until it works.
You then collect the data sent via UART via
flushinput(serials);
temp = fscanf(serials,'%s');
and then split the string. If data is sent continuously, you wrap this into a while loop.
After you are done, you can clean up via
fclose(s{i});
delete(instrfind)
instrreset
It should be noted, that establishing a connection takes longer, the more enabled COM ports there are. So it might be worth disabling all those you don't need.
For more specific things matlab can do, check out What Is the MATLAB Serial Port Interface
All,
I am attempting to communicate, over an SPP profile, with an RN4678 Bluetooth chip connected to a microcontroller.
I never have a problem with the Android app. I can always pair (if not paired), connect, send messages to the chip, and disconnect. An example session is below:
%CONNECT,AB9876543210%
%RFCOMM_OPEN%
%TEST% <-- Message sent using the keyboard ("Byte Stream Mode" option)
%RFCOMM_CLOSE%
%DISCONN%
With the iOS app, I can always pair (if not paired), connect, and disconnect. However, if I cannot send a message to the chip. An example session is below:
%LCONNECT,499B107AB1B5,1%
%LSECURED%
<-- Here I try to send a message, but it is never received
%DISCONN%
The funny thing is that if I first connect/disconnect using the Android, and then I connect using the iPhone/iPad, reception is successful !!!!
%LCONNECT,499B107AB1B5,1%
%LSECURED%
%TEST% <-- Yeah !!! Microcontroller receives the message
%DISCONN%
As far as I know, that path for the processing is the same ... In other words:
if(msg equals "RFCOMM_OPEN" or msg equals "LSECURED")
go to state that monitors incoming messages
I, therefore, kindly ask the following:
1 - Have you encountered anything similar? Do you have any hints? What could the Android App possibly do that the iPhone app is not doing? What am I overlooking or not understanding?
2 - Are you aware of an app that works for both iOS and Android? What I mean, designed by the SAME guy/company?
If you need more info, please ask. I simply did not want to be too 'verbose'.
Thank you for your assistance.
Sincerely,
Vincenzo
All,
At my job we have been playing with two RN modules: the RN4677 (we started with this module) and the RN4678.
The module allows the user to enter (and exit) a command mode. The RN4677 allows bidirectional communication with a manager while still in command mode. The RN4678 does NOT allow bidirectional communication with a manager while still in command mode.
All I needed to do was exit command mode (by issuing the command '---\r'). Now both modules work with Windows/Android/iOS ...
To summarize:
command "$$$\r" to enter command mode
various commands, requests for settings, ...
command "---\r" to exit command mode (a must for RN4678)
Everything will now work fine for both modules
I must say ... that was painful to troubleshoot ...
Sincerely,
Vincenzo
I'm working on getting any existing device communicating with Android devices. The device uses javax.usb (which is built on top of libusb) for usb communication and I am attempting to implement the Android Open Accessory Protocol using it. The device currently recognizes the android device and registers the android device with my application. However when I try to:
Attempt to Start in Accessory Mode - Send a 51 control request ("Get Protocol") to figure out if the device supports the Android accessory protocol.
I get a UsbStallException and my app dies. I know very little when it comes to usb from what I have been reading this should work.
Here's the relevant code:
byte req = (byte) (0x80 | 0x40);
UsbControlIrp irp = usbDev.createUsbControlIrp(req, (byte)51, (short)0, (short)0);
usbDev.syncSubmit(irp);
Any insights as to what I'm doing wrong would be appreciated.
PS: the device I'm running this on uses a 1.4 JVM so any solutions will be constrained by that