ir_rx/sony.py

   1 # sony.py Decoder for IR remote control using synchronous code
   2 # Sony SIRC protocol.
   3
   4 # Author: Peter Hinch
   5 # Copyright Peter Hinch 2020 Released under the MIT license
   6
   7 from utime import ticks_us, ticks_diff
   8 from ir_rx import IR_RX
   9
  10 class SONY_ABC(IR_RX):  # Abstract base class
  11     def __init__(self, pin, bits, callback, *args):
  12         # 20 bit block has 42 edges and lasts <= 39ms nominal. Add 4ms to time
  13         # for tolerances except in 20 bit case where timing is tight with a
  14         # repeat period of 45ms.
  15         t = int(3 + bits * 1.8) + (1 if bits == 20 else 4)
  16         super().__init__(pin, 2 + bits * 2, t, callback, *args)
  17         self._addr = 0
  18         self._bits = 20
  19
  20     def decode(self, _):
  21         try:
  22             nedges = self.edge  # No. of edges detected
  23             self.verbose and print('nedges', nedges)
  24             if nedges > 42:
  25                 raise RuntimeError(self.OVERRUN)
  26             bits = (nedges - 2) // 2
  27             if nedges not in (26, 32, 42) or bits > self._bits:
  28                 raise RuntimeError(self.BADBLOCK)
  29             self.verbose and print('SIRC {}bit'.format(bits))
  30             width = ticks_diff(self._times[1], self._times[0])
  31             if not 1800 < width < 3000:  # 2.4ms leading mark for all valid data
  32                 raise RuntimeError(self.BADSTART)
  33             width = ticks_diff(self._times[2], self._times[1])
  34             if not 350 < width < 1000:  # 600μs space
  35                 raise RuntimeError(self.BADSTART)
  36
  37             val = 0  # Data received, LSB 1st
  38             x = 2
  39             bit = 1
  40             while x <= nedges - 2:
  41                 if ticks_diff(self._times[x + 1], self._times[x]) > 900:
  42                     val |= bit
  43                 bit <<= 1
  44                 x += 2
  45             cmd = val & 0x7f  # 7 bit command
  46             val >>= 7
  47             if nedges < 42:
  48                 addr = val & 0xff  # 5 or 8 bit addr
  49                 val = 0
  50             else:
  51                 addr = val & 0x1f  # 5 bit addr
  52                 val >>= 5  # 8 bit extended
  53         except RuntimeError as e:
  54             cmd = e.args[0]
  55             addr = 0
  56             val = 0
  57         self.do_callback(cmd, addr, val)
  58
  59 class SONY_12(SONY_ABC):
  60     def __init__(self, pin, callback, *args):
  61         super().__init__(pin, 12, callback, *args)
  62
  63 class SONY_15(SONY_ABC):
  64     def __init__(self, pin, callback, *args):
  65         super().__init__(pin, 15, callback, *args)
  66
  67 class SONY_20(SONY_ABC):
  68     def __init__(self, pin, callback, *args):
  69         super().__init__(pin, 20, callback, *args)
  70