Parse serial input[UART] on ioio board from an arduino TX output

Question

I'm trying to have an Arduino UNO send values to a IOIO board (https://github.com/ytai/ioio/wiki/UART) over UART. As someone turns a rotary encoder, I want it to send a 0 for CW, 1 for CCW, and 2 for a press. Everything checks out in the Serial Monitor from the Arduino, but I don't know how to read the values and parse them on the Java-end correctly. It all comes through as seemingly random numbers, sometimes occasionally the correct number is there.

I've tried both of these methods on the Arduino side:

Serial.write(1);

byte data[] = {1};
Serial.write(data, 1);

Also Serial.write automatically writes to pin 1, so theres no need to create a SoftwareSerial object.

When reading this on the Java side, I just get mostly 255, occasionally the correct number, and occasionally a random number in between 0 and 255:

@Override
  public void connect() throws ConnectionLostException {
    try{
      // rx pin = 6
      mUart = ioio_.openUart(RX_PIN, IOIO.INVALID_PIN, 9600, Parity.NONE, StopBits.ONE);
      mInput = mUart.getInputStream();

    }
    catch(ConnectionLostException e){
      Log.e(TAG, "connection lost:" + e.getMessage());
      ioio_.disconnect();
      throw e;
    }
  }

  @Override
  public void loop(int loopCount) throws ConnectionLostException {

    try{
      byte[] response = new byte[1];
      int read = mInput.read();

    }catch(IOException e){
      Log.d(TAG, "error: " + e.getMessage());
    }
  }

I've also tried using BufferedReaders, while passing Strings through Serial.println, but a lot of crazy characters were getting output from the Java side (tried encoding in both UTF-8 and ASCII).

Baud rates are matched up at 9600, and I'm on a 5v RX pin on the IOIO, and that pin is connected to the TX pin (pin 1) on the Arduino Uno.

Does anyone point to a simple way of transmitting & receiving an integer?

Parse serial input[UART] on ioio board from an arduino TX output

0 Answers0