Content → Command Stations → RASCII

The RASCII protocol uses HEXA for all fields except the prefix and remark text.

The info text may not contain any of the prefixes. This will make the message invalid and will be rejected.

Serial monitor input is a way to provide easy setting up a unit, for example the WiFi settings.
The input should be read until a linefeed has been detected, and do not have a length field.

HEXA is the Hexadecimal-ASCII representation of a binary number.
A decimal value of 47, for example, is represented in HEXA as "2F".

Paratemers:

• s = HEXA string

Returns: The byte value

byte HexA2Byte( const char* s ) {
  byte h, l, val;
  if( s[0] >= 'A' ) h = s[0] - 55;
  else h = s[0] -48; 
  if( s[1] >= 'A' ) l = s[1] - 55;
  else l = s[1] -48; 
  val = l + (h << 4);
  return val;
}

Paratemers:

• b = Byte value
• s = Buffer for receiving the HEXA string

Returns: The pointer to the HEXA string buffer

const char* Byte2HexA(byte b, char* s) {
  static char cHex[] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
  s[0] = cHex[(b&0xF0)>>4];
  s[1] = cHex[ b&0x0F    ];
  s[2] = '\0';
  return s;
}

1. Read byte by byte until a prefix is detected.
2. Read the next two HEXA characters and convert them to a number for the length.
3. Read the number of bytes as set in the length field.
4. Convert the HEXA to Bytes.
5. Evaluate the message.
6. Repeat.

Board # FF is broadcast.

Board # FF is broadcast.

Events maybe acknowledged by the host program.

• https://gitlab.com/rocrail/Arduino/tree/master/libraries/RASCII
• rascii.zip

Some Windows configurations will crash at Rocrail server startup if the Arduino is connected by USB and the following option is not set:

• No device check at startup