from machine import Pin
import rp2
import time

PIN_IN = 4

@rp2.asm_pio()
def edge_detector():
    in_(pins, 1)
    mov(x, isr)
    label("loop")
    in_(pins, 1)
    mov(y, isr)
    jmp(x_not_y, "change")
    jmp("loop")
    label("change")
    mov(isr, y)
    push()
    mov(x, y)
    jmp("loop")

sm_in = rp2.StateMachine(0, edge_detector, freq=2000, in_base=Pin(PIN_IN))
sm_in.active(1)

print("检测 GPIO4 边沿...")
try:
    while True:
        if sm_in.rx_fifo():
            level = sm_in.get() & 1
            print(f"边沿！当前电平: {level}")
        time.sleep_us(100)
except KeyboardInterrupt:
    sm_in.active(0)
    print("结束")