Boost ASIO Serial Communication with Arduino: Error above 9600 bps

Question

I'm developing a C++ interface to communicate with na Arduino UNO which is running some code. To communicate with the Arduino, i'm using boost asio library. My application works well at a baud rate of 9600bps. Now, i wanted to communicate faster with the arduino, so, i tried to communicate at 115200bps, 57600bps, etc, without success.

At 115200bps, it seems that boost::write is sending two non-desirable bytes (both the same, with value ASCII 240 - this only happens for the first data transaction, so if i unplug and plug again the Arduino, this bytes will be sent during the first communication ). At this baud rate i can read the data that is being sent by Arduino (which is wrong for the first data communication, but is correct for the next ones).

At 57600bps, those 2 wrong bytes are not sent, but data is not read from arduino (it seems that write is not sending nothing).

The code to write to the serial is fairly simple, is just the boost::write and the code to read from the serial is just a loop and a boost::read of one byte (communications are synchronous just to test if everything was okay, which is not for higher baud rates than 9600bps).

The write function:

void sendMessage(char *c, unsigned int size) {

   serial.write(c, size);

   return;
}

The read function:

void readMessage(void) {
   char c;
   uint8_t count = 0;
   for (;;)
   {
      boost::asio::read(serial, boost::asio::buffer(&c, 1));
      cout << "Received char: " << static_cast<unsigned int>(c) << endl;
      if (count == 3 ){
         return;
      }
      count++;
   }

   return;
}

I know that the problem is not in the side of the arduino (that's why i posted the question here and not in the arduino stackexchange) because, using realterm and sending the exact same bytes that i send using boost, i get the proper reply from the Arduino for every baud rate (9600, 57600 and 115200bps).

If anyone can help, i would be appreciated, since at this moment i don't know which is the problem (and i'm a beginner to boost).

Best regards

Edit

At 74880 bps, I recieve four times the byte with value 252.

Boost ASIO Serial Communication with Arduino: Error above 9600 bps

0 Answers0