# Программа PWM-генератора с кнопкой.
# Запускать строго на отладочной плате RP2040 и Micropython!

# Использование: если синий светодиод горит, значит PWM работает, в противном случае PWM отключен.
# Включать/отключать PWM можно нажатием кнопки USR на плате с микроконтроллером.

import machine
from machine import Pin
import time
from time import ticks_ms

PWM_PIN = 23  # пин PWM
PWM_FREQ = 100  # частота PWM
PWM_DUTY_US = 100000  # длительность каждого импульса в микросекундах


class Button(object):
    rest_state = False
    # pin = None
    # pin_number = 0
    RELEASED = 'released'
    PRESSED = 'pressed'
    DEBOUNCE_TIME = 50

    def __init__(self, pin, rest_state = False, callback = None, internal_pullup = False, internal_pulldown = False, debounce_time = None):
        self.pin_number = pin
        self.rest_state = rest_state
        self.previous_state = rest_state
        self.current_state = rest_state
        self.previous_debounced_state = rest_state
        self.current_debounced_state = rest_state
        self.last_check_tick = ticks_ms()
        self.debounce_time = debounce_time or Button.DEBOUNCE_TIME
        if internal_pulldown:
            self.internal_pull = Pin.PULL_DOWN
            self.rest_state = False
        elif internal_pullup:
            self.internal_pull = Pin.PULL_UP
            self.rest_state = True
        else:
            self.internal_pull = None
        self.pin = Pin(pin, mode = Pin.IN, pull = self.internal_pull)
        self.callback = callback
        self.active = False
  
    def debounce(self):
        ms_now = ticks_ms()
        self.current_state = self.pin.value()
        state_changed = self.current_state != self.previous_state
        if state_changed:
            self.last_check_tick = ms_now
        state_stable = (ms_now - self.last_check_tick) > self.debounce_time
        if state_stable and not state_changed:
            self.last_check_tick = ms_now
            self.current_debounced_state = self.current_state
        self.previous_state = self.current_state

    def check_debounce_state(self):
        if self.current_debounced_state != self.previous_debounced_state:
            if self.current_debounced_state != self.rest_state:
                self.active = True
                if self.callback != None:
                    self.callback(self.pin_number, Button.PRESSED)
            else:
                self.active = False
                if self.callback != None:
                    self.callback(self.pin_number, Button.RELEASED)
        self.previous_debounced_state = self.current_debounced_state

    def update(self):
        self.debounce()
        self.check_debounce_state()


onboard_led = Pin(25, mode=Pin.OUT, value=0)
pwm_enabled = False
pwm = machine.PWM(Pin(PWM_PIN), freq=PWM_FREQ)


def pwm_button_callback(pin, state):
    global onboard_led, pwm_enabled, pwm
    if state == Button.PRESSED:
        pwm_enabled = not pwm_enabled
        if pwm_enabled:
            pwm.duty_ns(PWM_DUTY_US)
            print("PWM active!")
            onboard_led.value(1)
        else:
            pwm.duty_u16(0)
            print("PWM stoped!")
            onboard_led.value(0)


def main():
    #lcd = SoftwareLcd()
    bu = Button(pin=24, internal_pullup=True, callback=pwm_button_callback)
    while True:
        bu.update()
        #onboard_led.value(onboard_led.value() ^ 1)
        #lcd.send_data(0x40)
        time.sleep_ms(1)


if __name__ == '__main__':
    main()