# https://www.instructables.com/Respberry-Pi-Pico-W-NeoPixels-Experiments-With-Pro/

import time
import rp2
from machine import Pin

@rp2.asm_pio(set_init=rp2.PIO.OUT_LOW, out_shiftdir=rp2.PIO.SHIFT_LEFT)

def neo_prog():
    pull()                       # osr <= number of pixels - 1
    mov(y, osr)                  # y <= number of pixels - 1
    label("loop_pixel")
    mov(isr, y)                  # isr (pixel counter) <= y
    pull()                       # osr <= 24 bits GRB
    set(x, 23)                   # x (bit counter) <= 23
    label("loop_pixel_bit")
    out(y, 1)                    # y <= left-most 1 bit of osr
    jmp(not_y, "bit_0")
    set(pins, 1).delay(13)       # 1: high (7 cycles)
    set(pins, 0).delay(9)        # 1: low (5 cycles)
    jmp("bit_end")
    label("bit_0")
    set(pins, 1).delay(5)        # 0: high (3 cycles)
    set(pins, 0).delay(17)       # 0: low (9 cycles)
    label("bit_end")
    jmp(x_dec, "loop_pixel_bit") # x is bit counter
    mov(y, isr)                  # y <= isr (pixel counter)
    jmp(y_dec, "loop_pixel")     # y is pixel counter

sm = rp2.StateMachine(0, neo_prog, freq=20_000_000, set_base=Pin(12))
sm.active(1)


Pixels = []
for i in range(16):
    Pixels.append((i,0,0))

x = 0
N = 16
while(1):
    x = (x + 1) % 256
    sm.put(N-1)
    for i in range(0,N):
        g = 0;
        r = (i*5 + x) % 80;
        b = 80 - r;
        grb = (g << 16) + (r << 8) + b
        sm.put(grb << 8)
    time.sleep(0.05)