SDK • Re: IR transmission (ideally with PIO, but not necessarily)

Code:

from   machine import Pinfrom   rp2     import asm_pio, PIO, StateMachineimport timeOUTPUT_LED_PIN = "LED"led = Pin(OUTPUT_LED_PIN, Pin.OUT)@asm_pio(sideset_init = PIO.OUT_LOW)def IrBlast():  # Get the LED delay count and store it away in our 'Y' register  pull()                .side(0)  mov(y, osr)  # This is our main loop  label("MainLoop")  # Read the number of on cycles we need inot 'osr'  pull()  # The On part  label("OnPart")  # On loop  mov(x, y)             .side(1)  label(     "LedOnLoop")  jmp(x_dec, "LedOnLoop")  # Off loop  mov(x, y)             .side(0)  label(     "LedOffLoop")  jmp(x_dec, "LedOffLoop")  # Repeat the required number of n cycles, decrement 'osr'  mov(x, osr)  jmp(x_dec, "RepeatOnPart")  jmp("OffPart")  label("RepeatOnPart")  mov(osr, x)  jmp("OnPart")  # The off part  label("OffPart")  pull()  mov(x, osr)  label(     "OffLoop")  jmp(x_dec, "OffLoop")  # Handle next pair  jmp("MainLoop")# Find a free state machine or use one we hope isn't already being usedtry    : sm_number = PIO.FindFreeStateMachine()except : sm_number = 2# Run the state machine at 1 MHz so timing is in microsecondssm_frequency = 1000000# Initialise the state machine and set it runningsm = StateMachine(sm_number, IrBlast, freq=sm_frequency, sideset_base=led)sm.active(True)# For this demo we are using the on-board LED so timings are extended so we# can see the effects. When the LED is on it flashes at 2 HZ, 250ms on and# 250 ms off, a cycles takes 500 ms. We will therefore need 2 cycles per# one second period.# The first thing we need to pass to the PIO program is the LED modulation# high and low delay count for the PIO code. For a 2 Hz LED carrier the LED# is high and low for 250 ms, 250000 us. The PIO delay loops take 1 cycle# so the dleat count is the same.hz = 2delayCount = int(sm_frequency / hz / 2)print(delayCount)sm.put(delayCount)# Now we create a list of what we want to send.ir = []# We add a pair of items for each interaction, how many pulses of IR we# send for the on period, and how many cycles to delay with IR off after# that.## For our demo using the on-board LED we will have an initial two second# on period, a one second off period, then another one second on and one#  second off## For a two second on period, 2000000 us, it is 8 cycles of outputting# 2 Hz carrieronTimeUs = 2000000onCycles = int(onTimeUs / delayCount)# For an off time of one second, 1000000 us, the PIO takes 1 cycle per# microsecond so the off cyles needed is the same.offTimeUs = 1000000offCycles = offTimeUs# We add that to our list of what to sendir.append([onCycles, offCycles])# We repeat thse same for our subsequent one second on one second offonTimeUs  = 1000000onCycles  = int(onTimeUs / delayCount)offTimeUs = 1000000offCycles = offTimeUsir.append([onCycles, offCycles])# We simply blast that out with a five second gap between blasts##    |  2 s  |1 s|1 s|1 s|         |  2 s  |#    |-------|---|---|---|-- - - --|-------|## ___||||||||____||||_______ _ _ __||||||||___while True:  print("TX")  for onCycles, offCycles in ir:    print(" ", onCycles, offCycles)    sm.put(onCycles)    sm.put(offCycles)  time.sleep(5)