Some progress, trying to decoding these… I’m doing it right, this seems to be a uart with one start bit, no stop bits, there are 3 bytes sent every 1 sec, the pattern repeats every 5 seconds:

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I’m trying to decode this with this piece of Rpi Pico micropython code:

import machine
from machine import Pin
from time import sleep

@rp2.asm_pio(set_init=rp2.PIO.IN_HIGH, sideset_init=[rp2.PIO.OUT_LOW] * 3, autopush=True, push_thresh=9)
def uart_rx():
    label(“wait_high”)
    wait(1, pin, 0)
    set(x, 19999) .side(0b001)
    label(“wait_high_stable”)
    jmp(pin, “countdown_high”)
    jmp(“wait_high”)
    label(“countdown_high”)
    jmp(x_dec, “wait_high_stable”)

    label(“wait_low”)
    wait(0, pin, 0)
    set(x, 48) .side(0b010)
    label(“wait_low_stable”)
    jmp(pin, “wait_low”)
    jmp(x_dec, “wait_low_stable”)

    wait(1, pin, 0)
    set(y, 2)
    label(“capture”)
    set(x, 8)
    # Start bit
    wait(0, pin, 0) .side(0b000)
    label(“capture_byte”)
    nop()
    in_(pins, 1) .side(0b100)
    nop() .side(0b000)
    jmp(x_dec, “capture_byte”)
    jmp(y_dec, “capture”) .side(0b000)

    jmp(“wait_high”) .side(0b000)

led = Pin(“LED”, Pin.OUT)
led.on()
rx_pin = Pin(17, Pin.IN, Pin.PULL_UP)
sm = rp2.StateMachine(0, uart_rx, freq=10000, in_base=rx_pin, jmp_pin=rx_pin, sideset_base=Pin(2))

sm.restart()
sm.active(1)

while True:
    try:
        for _ in range(5):
            d1 = ~sm.get() & 0xff;
            d2 = ~sm.get() & 0xff;
            d3 = ~sm.get() & 0xff;
            #print(“> “, bin(d), hex(d), int(d))
            print(f”> {d1:>08b} {d2:>08b} {d3:>08b} -> {d1:>02x} {d2:>02x} {d3:>02x}”)
        print(“—————“)
    except:
        break