Source code for adafruit_irremote

# SPDX-FileCopyrightText: 2017 Scott Shawcroft for Adafruit Industries
#
# SPDX-License-Identifier: MIT

"""
`adafruit_irremote`
====================================================

Demo code for Circuit Playground Express:

.. code-block:: python

    # Circuit Playground Express Demo Code
    # Adjust the pulseio 'board.PIN' if using something else
    import pulseio
    import board
    import adafruit_irremote

    pulsein = pulseio.PulseIn(board.REMOTEIN, maxlen=120, idle_state=True)
    decoder = adafruit_irremote.GenericDecode()


    while True:
        pulses = decoder.read_pulses(pulsein)
        print("Heard", len(pulses), "Pulses:", pulses)
        try:
            code = decoder.decode_bits(pulses)
            print("Decoded:", code)
        except adafruit_irremote.IRNECRepeatException:  # unusual short code!
            print("NEC repeat!")
        except adafruit_irremote.IRDecodeException as e:     # failed to decode
            print("Failed to decode: ", e.args)

        print("----------------------------")

* Author(s): Scott Shawcroft

Implementation Notes
--------------------

**Hardware:**

* `CircuitPlayground Express <https://www.adafruit.com/product/3333>`_

* `IR Receiver Sensor <https://www.adafruit.com/product/157>`_

**Software and Dependencies:**

* Adafruit CircuitPython firmware for the ESP8622 and M0-based boards:
  https://github.com/adafruit/circuitpython/releases

"""

# Pretend self matter because we may add object level config later.
# pylint: disable=no-self-use

import array
import time

__version__ = "0.0.0-auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_IRRemote.git"


[docs]class IRDecodeException(Exception): """Generic decode exception"""
[docs]class IRNECRepeatException(Exception): """Exception when a NEC repeat is decoded"""
[docs]class GenericDecode: """Generic decoding of infrared signals"""
[docs] def bin_data(self, pulses): """Compute bins of pulse lengths where pulses are +-25% of the average. :param list pulses: Input pulse lengths """ bins = [[pulses[0], 0]] for _, pulse in enumerate(pulses): matchedbin = False # print(pulse, end=": ") for b, pulse_bin in enumerate(bins): if pulse_bin[0] * 0.75 <= pulse <= pulse_bin[0] * 1.25: # print("matches bin") bins[b][0] = (pulse_bin[0] + pulse) // 2 # avg em bins[b][1] += 1 # track it matchedbin = True break if not matchedbin: bins.append([pulse, 1]) # print(bins) return bins
[docs] def decode_bits(self, pulses): """Decode the pulses into bits.""" # pylint: disable=too-many-branches,too-many-statements # special exception for NEC repeat code! if ( (len(pulses) == 3) and (8000 <= pulses[0] <= 10000) and (2000 <= pulses[1] <= 3000) and (450 <= pulses[2] <= 700) ): raise IRNECRepeatException() if len(pulses) < 10: raise IRDecodeException("10 pulses minimum") # Ignore any header (evens start at 1), and any trailer. if len(pulses) % 2 == 0: pulses_end = -1 else: pulses_end = None evens = pulses[1:pulses_end:2] odds = pulses[2:pulses_end:2] # bin both halves even_bins = self.bin_data(evens) odd_bins = self.bin_data(odds) outliers = [b[0] for b in (even_bins + odd_bins) if b[1] == 1] even_bins = [b for b in even_bins if b[1] > 1] odd_bins = [b for b in odd_bins if b[1] > 1] if not even_bins or not odd_bins: raise IRDecodeException("Not enough data") if len(even_bins) == 1: pulses = odds pulse_bins = odd_bins elif len(odd_bins) == 1: pulses = evens pulse_bins = even_bins else: raise IRDecodeException("Both even/odd pulses differ") if len(pulse_bins) == 1: raise IRDecodeException("Pulses do not differ") if len(pulse_bins) > 2: raise IRDecodeException("Only mark & space handled") mark = min(pulse_bins[0][0], pulse_bins[1][0]) space = max(pulse_bins[0][0], pulse_bins[1][0]) if outliers: # skip outliers pulses = [ p for p in pulses if not (outliers[0] * 0.75) <= p <= (outliers[0] * 1.25) ] # convert marks/spaces to 0 and 1 for i, pulse_length in enumerate(pulses): if (space * 0.75) <= pulse_length <= (space * 1.25): pulses[i] = False elif (mark * 0.75) <= pulse_length <= (mark * 1.25): pulses[i] = True else: raise IRDecodeException("Pulses outside mark/space") # convert bits to bytes! output = [0] * ((len(pulses) + 7) // 8) for i, pulse_length in enumerate(pulses): output[i // 8] = output[i // 8] << 1 if pulse_length: output[i // 8] |= 1 return output
def _read_pulses_non_blocking( self, input_pulses, max_pulse=10000, pulse_window=0.10 ): """Read out a burst of pulses without blocking until pulses stop for a specified period (pulse_window), pruning pulses after a pulse longer than ``max_pulse``. :param ~pulseio.PulseIn input_pulses: Object to read pulses from :param int max_pulse: Pulse duration to end a burst :param float pulse_window: pulses are collected for this period of time """ received = None recent_count = 0 pruning = False while True: while input_pulses: pulse = input_pulses.popleft() recent_count += 1 if pulse > max_pulse: if received is None: continue pruning = True if not pruning: if received is None: received = [] received.append(pulse) if recent_count == 0: return received recent_count = 0 time.sleep(pulse_window)
[docs] def read_pulses( self, input_pulses, *, max_pulse=10000, blocking=True, pulse_window=0.10, blocking_delay=0.10 ): """Read out a burst of pulses until pulses stop for a specified period (pulse_window), pruning pulses after a pulse longer than ``max_pulse``. :param ~pulseio.PulseIn input_pulses: Object to read pulses from :param int max_pulse: Pulse duration to end a burst :param bool blocking: If True, will block until pulses found. If False, will return None if no pulses. Defaults to True for backwards compatibility :param float pulse_window: pulses are collected for this period of time :param float blocking_delay: delay between pulse checks when blocking """ while True: pulses = self._read_pulses_non_blocking( input_pulses, max_pulse, pulse_window ) if blocking and pulses is None: time.sleep(blocking_delay) continue return pulses
[docs]class GenericTransmit: """Generic infrared transmit class that handles encoding. :param int header: The length of header in microseconds :param int one: The length of a one in microseconds :param int zero: The length of a zero in microseconds :param int trail: The length of the trail in microseconds, set to None to disable :param bool debug: Enable debug output, default False """ def __init__(self, header, one, zero, trail, *, debug=False): self.header = header self.one = one self.zero = zero self.trail = trail self.debug = debug
[docs] def transmit(self, pulseout, data, *, repeat=0, delay=0, nbits=None): """Transmit the ``data`` using the ``pulseout``. :param pulseio.PulseOut pulseout: PulseOut to transmit on :param bytearray data: Data to transmit :param int repeat: Number of additional retransmissions of the data, default 0 :param float delay: Delay between any retransmissions, default 0 :param int nbits: Optional number of bits to send, useful to send fewer bits than in the data bytes """ bits_to_send = len(data) * 8 if nbits is not None and nbits < bits_to_send: bits_to_send = nbits durations = array.array( "H", [0] * (2 + bits_to_send * 2 + (0 if self.trail is None else 1)) ) durations[0] = self.header[0] durations[1] = self.header[1] if self.trail is not None: durations[-1] = self.trail out = 2 bit_count = 0 for byte_index, _ in enumerate(data): for i in range(7, -1, -1): if (data[byte_index] & 1 << i) > 0: durations[out] = self.one[0] durations[out + 1] = self.one[1] else: durations[out] = self.zero[0] durations[out + 1] = self.zero[1] out += 2 bit_count += 1 if bit_count >= bits_to_send: break if self.debug: print(durations) pulseout.send(durations) for _ in range(repeat): if delay: time.sleep(delay) pulseout.send(durations)