1# See original soft_pwm.py for detailed comments.
2import uasyncio
3from hwconfig import LED
4
5
6async def pwm_cycle(led, duty, cycles):
7    duty_off = 20 - duty
8    for i in range(cycles):
9        if duty:
10            led.value(1)
11            await uasyncio.sleep_ms(duty)
12        if duty_off:
13            led.value(0)
14            await uasyncio.sleep_ms(duty_off)
15
16
17async def fade_in_out(LED):
18    while True:
19        # Fade in
20        for i in range(1, 21):
21            await pwm_cycle(LED, i, 2)
22        # Fade out
23        for i in range(20, 0, -1):
24            await pwm_cycle(LED, i, 2)
25
26
27loop = uasyncio.get_event_loop()
28loop.run_until_complete(fade_in_out(LED))
29