# %%micropython
# Example using PIO to create a UART TX interface

from machine import Pin
from rp2 import PIO, StateMachine, asm_pio

# remove all programs from both PIOs
for n in (0, 1):
    pio = PIO(n)
    pio.remove_program()
# -----------------------------------------------
# Wiring scema for the DMX TX
pin_dmx_tx = Pin(15, Pin.OUT)
pin_dmx_rx = Pin(14, Pin.IN)

# Minimum universe length is ~5 channels / slots 


@asm_pio(
    set_init=PIO.OUT_LOW,
    sideset_init=PIO.OUT_LOW,
    out_init=PIO.OUT_LOW,
    autopull=True,  # ?
    out_shiftdir=PIO.SHIFT_LEFT,  # ?
)
# fmt: off
def dmx_send():
    BREAK_LOOPS = 23
    # Assert break condition
    # Sender DMX break signal is 92us >, so we need to loop at least 92 / 8 = 12 times
    # TODO: Actually should be at least 92us
    set(x, 21)      .side(0)                # Preload bit counter, assert break condition for 176us

    label("breakloop")                      # Loop X times, each loop iteration is 8 cycles.
    jmp(x_dec, "breakloop")             [7] # Each loop iteration is 8 cycles.

    # Assert start condition
    nop() [7]                   .side(1)   # Assert MAB. 8 cycles nop and 8 cycles stop-bits = 16us

    # Send data frame
    wrap_target()
    pull()                   .side(1)   [7] # Assert 2 stop bits, or stall with line in idle state
    set(x, 7)                .side(0)   [3] # load bit counter, assert start bit for 4 clocks

    label("bitloop")
    out(pins, 1)                            # Shift 1 bit from OSR to the first OUT pin
    jmp(x_dec, "bitloop")    .side(0)   [2] # Each loop iteration is 4 cycles.

    wrap()
# fmt: on


# Usage example
sm_dmx_tx = StateMachine(
    0,
    dmx_send,
    freq=1_000_000,
    set_base=pin_dmx_tx,
    out_base=pin_dmx_tx,
    sideset_base=pin_dmx_tx,
)

size = 8


print(size)
universe = bytearray(1 + size)  # 1 start code + 512 channels
# set all channels to 0
for i in range(len(universe)):
    universe[i] = 200
# for i in range(len(universe)):
#     universe[i] = i % 256
sm_dmx_tx.active(1)

import time

while 1:
    sm_dmx_tx.active(0)
    sm_dmx_tx.restart()
    sm_dmx_tx.active(1)
    sm_dmx_tx.put(universe)
    print("...")
    time.sleep(0.1)