Im new here and just started implementing a graphing interface for AVR mcu. I have this piece of code which sends a data packet frame via serial to avr and it has a start and an end packet. I originally coded in C#. And could some one please help me implement this in processing ?
Basically all I want to do is send the following. But a byte I believe is from -128 to 128 and not 0 - 255. How can I easily do this conversion ?
DLE
packet id -> 0 - 255 bytes
error id -> 0 - 255 bytes
packet size -> 0 - 255 bytes
payload -> array of bytes (0-255)
checksum -> 0 - 255 bytes
DLE
ETX
Heres the code,
byte _packetID;
byte _errorCode;
byte _defaultPacketByteCount;
byte _packetByteCount = 4;
byte[] _dataPayload = new Byte[251];
int _dataPtr = 0;
byte _checkSum = 0;
byte DLE = (byte)10;
byte ETX = (byte)3;
_packetID = (byte)2;
_errorCode = (byte)1;
_packetByteCount++;
_dataPtr++;
_dataPayload[0] = (byte)1;
_checkSum = calcCheckSum();
byte[] packet = new byte[ 7 ];
packet[0] = DLE;
packet[1] = _packetID;
packet[2] = _errorCode;
packet[3] = _packetByteCount;
packet[4] = _checkSum;
packet[5] = DLE;
packet[6] = ETX;
myPort.write (packet);
// checksum function
byte calcCheckSum()
{
//checksum calculated as sum of all bytes XORed with 0xFF.
