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

class PIO_TPO:
    def __init__(self, sm_id, pin, prop_band):
        self._sm = StateMachine(sm_id, self.tpo_prog, freq=60_000_000 // prop_band, set_base=Pin(pin))
        max_count=1000
        max_count=max_count-4
        self._sm.put(max_count)
        self._sm.exec("pull()")
        self._sm.exec("mov(isr, osr)")
        self._sm.active(1)
        self._max_count = max_count

    @asm_pio(set_init=PIO.OUT_LOW)
    def tpo_prog():
        set (pins,0)[29]
        pull(noblock)[29]
        mov(x, osr) [29] 
        mov(y, isr) [29]
        label("pwmloop")
        jmp(x_not_y, "skip") [29]
        set(pins,1) [29]
        label("skip")
        jmp(y_dec, "pwmloop") [29]

    def set(self, value):
        value = max(value, -1)
        value = (min(value, self._max_count))-1
        self._sm.put(value)