/arduino-smartrix

A message protocol for turning on or off LEDs in up to 16 MAX72xx matrices

Primary LanguageArduinoMIT LicenseMIT

arduino-smartrix

A message protocol for turning on or off LEDs in up to 16 MAX72xx matrices.

Info about the wiring: http://playground.arduino.cc/Main/MAX72XXHardware

Message structure

One message contains information for up to 64 LEDs in a Matrix connected to one MAX72xx device (up to 16 devices are addressable)

  • Byte 1: A hex char identifying the MAX72xx device (0 to 15)
  • Byte 2: A hex char defining the number of rows (up to 8)
  • Byte 3: A hex char defining the number of columns (up to 8)
  • Bytes 4 to 19: Each byte is a hex char containing status information (on/off) for 4 LEDs (1 to 16 bytes)
  • The last byte is a termination character (;)

Example for a 4x3 LED Matrix

1: LED is on

0: LED is off

[[ 0, 0, 1 ],
 [ 0, 1, 0 ],
 [ 1, 1, 1 ],
 [ 0, 0, 0 ]]

Binary representation of the matrix: 0010 1011 1000

Hex representation of the matrix: 2 B 8

Serial message sent to the arduino: 0432B8;

The first byte (0) addresses the first MAX72xx device, the second byte (4) defines a number of 4 rows, the third byte (3) defines a number of 3 columns, bytes 4 to 6 (2B8) are the hex representation of the 4x3 matrix (see above). The last byte (;) is the termination byte.

Example for a 8x8 LED Matrix

To turn on all LEDs of a 8x8 Matrix send this message to the Arduino

088FFFFFFFFFFFFFFFF;