from machine import Pin
import machine
import time
import asyncio

class StatusLED:
    led: Pin
    _status: int
    _period: float
    _duty_cycle: float

    def __init__(self):
        self.led = Pin("LED", Pin.OUT)
        self._status = 1
        self._period = 1
        self._duty_cycle = 0.5

    def status(self, status: int):
        self._status = status
        
    
    async def task(self):
        while True:
            t_1 = self._duty_cycle * self._period
            t_2 = (1 - self._duty_cycle) * self._period

            t_blink = t_1 / self._status / 2
            for _ in range(self._status):
                self.led.value(1)
                await asyncio.sleep(t_blink)
                self.led.value(0)
                await asyncio.sleep(t_blink)
            
            await asyncio.sleep(t_2)

STATUS_LED = StatusLED()


class UltraSonicSensor:
    """
    See https://randomnerdtutorials.com/micropython-hc-sr04-ultrasonic-esp32-esp8266/
    """

    tx: Pin
    rx: Pin

    def __init__(self, tx: int, rx: int):
        self.tx = Pin(tx, Pin.OUT)
        self.rx = Pin(rx, Pin.IN)
        
    def query_mm(self):
        self.tx.value(0)
        time.sleep_us(5)
        self.tx.value(1)
        time.sleep_us(10)
        self.tx.value(0)
        
        pulse_time = machine.time_pulse_us(self.rx, 1, 500*2*30)
        if pulse_time < 0:
            return None
        
        return pulse_time * 100 // 582
    


async def _main():
    asyncio.create_task(STATUS_LED.task())
    sensor = UltraSonicSensor(22, 21)
    while True:
        d = sensor.query_mm()
        print(f"d: {d} mm")
        await asyncio.sleep(0.5)

def main():
    asyncio.run(_main())


if __name__ == "__main__":
    main()