# Copyright (c) 2020 Peter Hinch
from sys import platform
-ESP32 = platform == 'esp32' or platform == 'esp32_LoBo'
+ESP32 = platform == 'esp32' # Loboris not supported owing to RMT
if ESP32:
- from machine import Pin, Timer, PWM, freq
+ from machine import Pin, PWM
+ from esp32 import RMT
else:
from pyb import Pin, Timer # Pyboard does not support machine.PWM
from micropython import const
from array import array
-import micropython
-
+from time import ticks_us, ticks_diff
+# import micropython
# micropython.alloc_emergency_exception_buf(100)
-# ABC only
-_SPACE = const(0)
-# If the wiring is such that 3.3V turns the LED off, set _SPACE as follows
-# On Pyboard 100, on ESP32 1023
+# On ESP32 gate hardware design is led_on = rmt and carrier
+
# Shared by NEC
STOP = const(0) # End of data
# IR abstract base class. Array holds periods in μs between toggling 36/38KHz
# carrier on or off. Physical transmission occurs in an ISR context controlled
-# by timer 2 and timer 5. See README.md for details of operation.
+# by timer 2 and timer 5. See TRANSMITTER.md for details of operation.
class IR:
+ _active_high = True # Hardware turns IRLED on if pin goes high.
+ _space = 0 # Duty ratio that causes IRLED to be off
+ timeit = False # Print timing info
+
+ @classmethod
+ def active_low(cls):
+ if ESP32:
+ raise ValueError('Cannot set active low on ESP32')
+ cls._active_high = False
+ cls._space = 100
def __init__(self, pin, cfreq, asize, duty, verbose):
if ESP32:
- freq(240000000)
- self._pwm = PWM(pin) # Produces 36/38/40KHz carrier
- self._pwm.deinit()
- self._pwm.init(freq=cfreq, duty=_SPACE)
- # ESP32: 0 <= duty <= 1023
- self._duty = round((duty if not _SPACE else (100 - duty)) * 10.23)
- self._tim = Timer(-1) # Controls carrier on/off times
- self._off = self.esp_off # Turn IR LED off
- self._onoff = self.esp_onoff # Set IR LED state and refresh timer
+ self._rmt = RMT(0, pin=pin, clock_div=80, carrier_freq=cfreq,
+ carrier_duty_percent=duty) # 1μs resolution
else: # Pyboard
+ if not IR._active_high:
+ duty = 100 - duty
tim = Timer(2, freq=cfreq) # Timer 2/pin produces 36/38/40KHz carrier
self._ch = tim.channel(1, Timer.PWM, pin=pin)
- self._ch.pulse_width_percent(_SPACE) # Turn off IR LED
+ self._ch.pulse_width_percent(self._space) # Turn off IR LED
# Pyboard: 0 <= pulse_width_percent <= 100
- self._duty = duty if not _SPACE else (100 - duty)
+ self._duty = duty
self._tim = Timer(5) # Timer 5 controls carrier on/off times
- self._off = self.pb_off
- self._onoff = self.pb_onoff
- self._tcb = self.cb # Pre-allocate
+ self._tcb = self._cb # Pre-allocate
+ self._arr = array('H', 0 for _ in range(asize)) # on/off times (μs)
+ self._mva = memoryview(self._arr)
+ # Subclass interface
self.verbose = verbose
- self.arr = array('H', 0 for _ in range(asize)) # on/off times (μs)
self.carrier = False # Notional carrier state while encoding biphase
self.aptr = 0 # Index into array
- # Before populating array, zero pointer, set notional carrier state (off).
- def transmit(self, addr, data, toggle=0): # NEC: toggle is unused
- self.aptr = 0 # Inital conditions for tx: index into array
- self.carrier = False
- self.tx(addr, data, toggle)
- self.append(STOP)
- self.aptr = 0 # Reset pointer
- self.cb(self._tim) # Initiate physical transmission.
-
- # Turn IR LED off (pyboard and ESP32 variants)
- def pb_off(self):
- self._ch.pulse_width_percent(_SPACE)
-
- def esp_off(self):
- self._pwm.duty(_SPACE)
-
- # Turn IR LED on or off and re-initialise timer (pyboard and ESP32 variants)
- @micropython.native
- def pb_onoff(self, p, v):
- self._ch.pulse_width_percent(_SPACE if p & 1 else self._duty)
- self._tim.init(prescaler=84, period=v, callback=self._tcb)
-
- @micropython.native
- def esp_onoff(self, p, v):
- self._pwm.duty(_SPACE if p & 1 else self._duty)
- self._tim.init(mode=Timer.ONE_SHOT, freq=v, callback=self.cb)
-
- def cb(self, t): # T5 callback, generate a carrier mark or space
+ def _cb(self, t): # T5 callback, generate a carrier mark or space
t.deinit()
p = self.aptr
- v = self.arr[p]
+ v = self._arr[p]
if v == STOP:
- self._off() # Turn off IR LED.
+ self._ch.pulse_width_percent(self._space) # Turn off IR LED.
return
- self._onoff(p, v)
+ self._ch.pulse_width_percent(self._space if p & 1 else self._duty)
+ self._tim.init(prescaler=84, period=v, callback=self._tcb)
self.aptr += 1
- def append(self, *times): # Append one or more time peiods to .arr
+ # Public interface
+ # Before populating array, zero pointer, set notional carrier state (off).
+ def transmit(self, addr, data, toggle=0, validate=False): # NEC: toggle is unused
+ t = ticks_us()
+ if validate:
+ if addr > self.valid[0] or addr < 0:
+ raise ValueError('Address out of range', addr)
+ if data > self.valid[1] or data < 0:
+ raise ValueError('Data out of range', data)
+ if toggle > self.valid[2] or toggle < 0:
+ raise ValueError('Toggle out of range', toggle)
+ self.aptr = 0 # Inital conditions for tx: index into array
+ self.carrier = False
+ self.tx(addr, data, toggle) # Subclass populates ._arr
+ self.trigger() # Initiate transmission
+ if self.timeit:
+ dt = ticks_diff(ticks_us(), t)
+ print('Time = {}μs'.format(dt))
+
+ # Subclass interface
+ def trigger(self): # Used by NEC to initiate a repeat frame
+ if ESP32:
+ self._rmt.write_pulses(tuple(self._mva[0 : self.aptr]), start = 1)
+ else:
+ self.append(STOP)
+ self.aptr = 0 # Reset pointer
+ self._cb(self._tim) # Initiate physical transmission.
+
+ def append(self, *times): # Append one or more time peiods to ._arr
for t in times:
- if ESP32 and t:
- t -= 350 # ESP32 sluggishness
- t = round(1_000_000 / t) # Store in Hz
- self.arr[self.aptr] = t
+ self._arr[self.aptr] = t
self.aptr += 1
self.carrier = not self.carrier # Keep track of carrier state
self.verbose and print('append', t, 'carrier', self.carrier)
- def add(self, t): # Increase last time value
+ def add(self, t): # Increase last time value (for biphase)
assert t > 0
self.verbose and print('add', t)
# .carrier unaffected
- if ESP32:
- t -= 350
- self.arr[self.aptr - 1] = round((self.arr[self.aptr - 1] / 1_000_000 + t) / 1_000_000)
- else:
- self.arr[self.aptr - 1] += t
+ self._arr[self.aptr - 1] += t
+
+
+# Given an iterable (e.g. list or tuple) of times, emit it as an IR stream.
+class Player(IR):
+
+ def __init__(self, pin, freq=38000, verbose=False): # NEC specifies 38KHz
+ super().__init__(pin, freq, 68, 33, verbose) # Measured duty ratio 33%
+
+ def play(self, lst):
+ for x, t in enumerate(lst):
+ self._arr[x] = t
+ self.aptr = x + 1
+ self.trigger()
projects / micorpython_ir.git / blobdiff