new_contents: #!/usr/bin/python
  
  import serial
  import time
  import sys
  
  PROTO_SOF        = ord('S')
  PROTO_SOF_LONG   = ord('T')
  PROTO_EOF        = ord('E')
  PROTO_CMD_SYNC   = 0x80
  PROTO_ADDR_BCAST = 0xFF
  
  crcTable = [
  	0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15,
  	0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d,
  	0x70, 0x77, 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65,
  	0x48, 0x4f, 0x46, 0x41, 0x54, 0x53, 0x5a, 0x5d,
  	0xe0, 0xe7, 0xee, 0xe9, 0xfc, 0xfb, 0xf2, 0xf5,
  	0xd8, 0xdf, 0xd6, 0xd1, 0xc4, 0xc3, 0xca, 0xcd,
  	0x90, 0x97, 0x9e, 0x99, 0x8c, 0x8b, 0x82, 0x85,
  	0xa8, 0xaf, 0xa6, 0xa1, 0xb4, 0xb3, 0xba, 0xbd,
  	0xc7, 0xc0, 0xc9, 0xce, 0xdb, 0xdc, 0xd5, 0xd2,
  	0xff, 0xf8, 0xf1, 0xf6, 0xe3, 0xe4, 0xed, 0xea,
  	0xb7, 0xb0, 0xb9, 0xbe, 0xab, 0xac, 0xa5, 0xa2,
  	0x8f, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9d, 0x9a,
  	0x27, 0x20, 0x29, 0x2e, 0x3b, 0x3c, 0x35, 0x32,
  	0x1f, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0d, 0x0a,
  	0x57, 0x50, 0x59, 0x5e, 0x4b, 0x4c, 0x45, 0x42,
  	0x6f, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7d, 0x7a,
  	0x89, 0x8e, 0x87, 0x80, 0x95, 0x92, 0x9b, 0x9c,
  	0xb1, 0xb6, 0xbf, 0xb8, 0xad, 0xaa, 0xa3, 0xa4,
  	0xf9, 0xfe, 0xf7, 0xf0, 0xe5, 0xe2, 0xeb, 0xec,
  	0xc1, 0xc6, 0xcf, 0xc8, 0xdd, 0xda, 0xd3, 0xd4,
  	0x69, 0x6e, 0x67, 0x60, 0x75, 0x72, 0x7b, 0x7c,
  	0x51, 0x56, 0x5f, 0x58, 0x4d, 0x4a, 0x43, 0x44,
  	0x19, 0x1e, 0x17, 0x10, 0x05, 0x02, 0x0b, 0x0c,
  	0x21, 0x26, 0x2f, 0x28, 0x3d, 0x3a, 0x33, 0x34,
  	0x4e, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5c, 0x5b,
  	0x76, 0x71, 0x78, 0x7f, 0x6a, 0x6d, 0x64, 0x63,
  	0x3e, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2c, 0x2b,
  	0x06, 0x01, 0x08, 0x0f, 0x1a, 0x1d, 0x14, 0x13,
  	0xae, 0xa9, 0xa0, 0xa7, 0xb2, 0xb5, 0xbc, 0xbb,
  	0x96, 0x91, 0x98, 0x9f, 0x8a, 0x8d, 0x84, 0x83,
  	0xde, 0xd9, 0xd0, 0xd7, 0xc2, 0xc5, 0xcc, 0xcb,
  	0xe6, 0xe1, 0xe8, 0xef, 0xfa, 0xfd, 0xf4, 0xf3,
  ]
  
  def serial_write(buf):
      global ser
      buf = [ chr(x) for x in buf ]
      out = ''.join(buf)
      print "Writing", len(out), "length packet:", repr(buf)
      if ser:
          ser.write(out)
  
  def send_short(addr, command, value):
      crc = 0
      crc = crcTable[crc ^ addr]
      crc = crcTable[crc ^ command]
      crc = crcTable[crc ^ value]
      serial_write([ PROTO_SOF, addr, command, value, crc, PROTO_EOF ])
  
  def send_long(addr, *data):
      assert len(data) > 0
      assert len(data) % 4 == 0
      serial_write([ PROTO_SOF_LONG, addr, 0, len(data)/4 ] + list(data) + [ PROTO_EOF ])
  
  
  # Color sequence
  sequence = [
          (255,   0,   0,  0),
          (  0, 255,   0,  0),
          (  0,   0, 255,  0),
          #(  0,   0,   0,  0),
      ]
  
  if __name__ == "__main__":
      if len(sys.argv) > 1:
          device = sys.argv[1]
          baud = int(sys.argv[2]) if len(sys.argv) > 2 else 115200*2
          ser = serial.Serial(device, baud)
      else:
          ser = False
  
      if False:
          # set everything to bright white
          send_long(0, *((255,255,255,0)*80))
          send_short(PROTO_ADDR_BCAST, PROTO_CMD_SYNC, 0)
  
      else:
          # Cycle through the colors in the "sequence" variable
          while True:
              for color in sequence:
                  send_long(0, *(color*80))
                  send_short(PROTO_ADDR_BCAST, PROTO_CMD_SYNC, 0)
                  print
                  time.sleep(0.25);
  
subject: Store the test program I wrote a while ago in git.