I'm currently working on an application, which would send a message to a Bluetooth LE device. Everything works fine on the first start up, but on the second start up, I get an exception.
Application Code
getDevices() function
public async Task<List<string>> getDevices()
{
Debug.WriteLine("C");
foreach (DeviceInformation di in await DeviceInformation.FindAllAsync(GattDeviceService.GetDeviceSelectorFromUuid(new Guid("0000ffe0-0000-1000-8000-00805f9b34fb"))))
{
Debug.WriteLine("D");
Debug.WriteLine(di.Name);
Debug.WriteLine(di.Id);
Debug.WriteLine(di.IsEnabled);
GattDeviceService bleService = await GattDeviceService.FromIdAsync(di.Id);
Debug.WriteLine(bleService.Device.ConnectionStatus.ToString());
Debug.WriteLine("E");
Debug.WriteLine(GattCharacteristic.ConvertShortIdToUuid(0xFFE1).ToString());
// TODO: Throws exception if not paired before startup because pairing info is not stored on device
accConfig = bleService.GetCharacteristics(GattCharacteristic.ConvertShortIdToUuid(0xFFE1))[0];
Debug.WriteLine("F");
}
return deviceList;
}
sendMessage() function
public async void sendMessage(string messageToSend)
{
// TODO: implement
await accConfig.WriteValueAsync((Encoding.UTF8.GetBytes(messageToSend)).AsBuffer());
Debug.WriteLine("G");
}
Errors
At the await accConfig line I get an exception:
An exception of type 'System.Exception' occurred in mscorlib.ni.dll but was not handled in user code
Additional information: [...] (Exception from HRESULT: 0x80070572)
Another thing is that on the Settings tab, my Bluetooth Device keeps switching from Connected to Paired all the time. I have no idea what causes that.
UPDATE 2017/04/23 Device Code and Info
I include the code on the Arduino. I'm using an original HM-10, on this page the first version on the top. Mine is unbranded (so it doesn't have the Keyes logo) but other than that it should not have any difference. (Though it could be a clone, but I doubt it as much as I know).
#include <SoftwareSerial.h>
SoftwareSerial bluetooth(9, 10); // RX, TX
char commandbuffer[50];
int j = 0;
void setup()
{
memset(commandbuffer, 0, sizeof(commandbuffer));
analogWrite(12, 255);
analogWrite(11, 0);
// Start the hardware serial port
Serial.begin(19200);
bluetooth.begin(9600);
// un REM this to set up a Master and connect to a Slave
Serial.println("BLE CC41A Bluetooth");
Serial.println("----------------------------------");
Serial.println("");
Serial.println("Trying to connect to Slave Bluetooth");
delay(1000);
bluetooth.print("AT"); // just a check
delay(2000);
delay(2000);
bluetooth.print("AT+ROLE0");
delay(2000);
/*
bluetooth.println("AT+HELP");
delay(2000);
bluetooth.println("AT+CONA0xE4F89CF8AB87");*/
/*bluetooth.println("AT+CONE4F89CF8AB87");
delay(2000);*/
// discover
/*
bluetooth.println("AT+INQ"); // look for nearby Slave
delay(5000);
bluetooth.println("AT+CONN1"); // connect to it */
}
void loop()
{
bluetooth.listen();
// while there is data coming in, read it
// and send to the hardware serial port:
while (bluetooth.available() > 0) {
char inByte = bluetooth.read();
Serial.write(inByte);
}
// Read user input if available.
if (Serial.available()) {
delay(10); // The DELAY!
char temp = Serial.read();
if (temp == '\n')
{
bluetooth.print(commandbuffer);
Serial.print('\n'); // Because it needs it even if Bluetooth received command happened earlier
Serial.println(commandbuffer);
memset(commandbuffer, 0, sizeof(commandbuffer));
j = 0; // Reset
}
else
{
commandbuffer[j++] = temp;
}
delay(500);
}
}
