# Exercise No. 5 - Control of MK II Servo
# Libraries...
from machine import Pin, PWM, ADC
import time

# Pins...
servo = PWM(Pin(0), freq=50)  # Set GP 0 as PWM pin.
bt1 = Pin(16, Pin.IN, Pin.PULL_DOWN)  # Button to position at 0°.
bt2 = Pin(17, Pin.IN, Pin.PULL_DOWN)  # Button to position at 180°.
converter = ADC(0)  # Pin to connect the potentiometer to the converter.

# Variables...
control = 0  # Control for functions.
high_time = 0  # High time of the PWM.
aux_1 = 0  # Control to enable or disable the potentiometer.
aux_2 = 90  # Default position for the servo.

# Functions...
def button_1(pin):
    global control
    control = 1

def button_2(pin):
    global control
    control = 2

# Interrupts...
bt1.irq(handler=button_1, trigger=Pin.IRQ_RISING)  # Trigger on button 1 press.
bt2.irq(handler=button_2, trigger=Pin.IRQ_RISING)  # Trigger on button 2 press.

# Main...
print("Limit set to ", aux_2, "°.")

while True:
    if control == 1:  # If button 1 is pressed.
        if aux_1 == 0:
            aux_1 = 1
            print("DISABLE POTENTIOMETER")
            # servo.deinit()  # Optional: De-initialize servo.
        elif aux_1 >= 1:
            aux_1 = 0
            print("ENABLE POTENTIOMETER")
            # servo.deinit()  # Optional: De-initialize servo.
        control = 0  # Reset control.

    if control == 2:  # If button 2 is pressed.
        if aux_2 == 90:
            aux_2 = 180
            print("180°.")
        elif aux_2 >= 180:
            aux_2 = 90
            print("90°.")
        control = 0  # Reset control.
    else:
        if aux_1 == 0:  # If potentiometer is enabled.
            potentiometer = int(converter.read_u16() * aux_2 / 65535)  # Convert ADC resolution to degrees.
            high_time = (potentiometer + 45) * 100000 / 9  # Convert degrees to time (ns).
            servo.duty_ns(int(high_time))  # Set the PWM high time for the servo.
            time.sleep(0.002)  # Small delay.
        if aux_1 == 1:  # If potentiometer is disabled.
            servo.duty_u16(1310)  # Fix servo at 0° - Duty cycle = 2%.
            time.sleep(0.002)  # Small delay.