src/python/bootloader.py

   1
   2 INIT_SEQ = [0xEC,0x04,0x32,ord('b'),ord('l')]
   3
   4 BIND_SEQ = [0xEC,0x04,0x32,ord('b'),ord('d')]
   5
   6 MODEL_SEQ = [0xEC,0x04,0x32,ord('m'),ord('m')]
   7
   8 def calc_crc8(payload, poly=0xD5):
   9     crc = 0
  10     for data in payload:
  11         crc ^= data
  12         for _ in range(8):
  13             if crc & 0x80:
  14                 crc = (crc << 1) ^ poly
  15             else:
  16                 crc = crc << 1
  17     return crc & 0xFF
  18
  19 def get_telemetry_seq(seq, key=None):
  20     payload = list(seq)
  21     if payload:
  22         if key:
  23             if type(key) == str:
  24                 key = [ord(x) for x in key]
  25             payload += key
  26             payload[1] += len(key)
  27         payload += [calc_crc8(payload[2:])]
  28     return bytes(payload)
  29
  30 def get_init_seq(key=None):
  31     return get_telemetry_seq(INIT_SEQ, key)
  32
  33 def get_bind_seq(key=None):
  34     return get_telemetry_seq(BIND_SEQ, key)
  35
  36 def get_model_seq(model):
  37     return get_telemetry_seq(MODEL_SEQ, model)