from micropython import const
from machine import Pin, PWM, ADC
import time

print("---- Program start ----")

try:
    # RGB PWMs - Pins 25, 27, 26
    # Frequency 1000Hz is good for LEDs to avoid flickering
    r_pwm = PWM(Pin(25), freq=1000)
    g_pwm = PWM(Pin(27), freq=1000)
    b_pwm = PWM(Pin(26), freq=1000)

    # ADC Pin - Potentiometer on Pin 34
    pot = ADC(Pin(34))
    pot.atten(ADC.ATTN_11DB)  # Allows reading up to ~3.3V
except Exception as e:
    print("Hardware error: ", e)

def voltage_to_rgb_duty_values(val, adc_r=65535):
    """
    Map ADC value (0-65535) to RGB transitions.
    """
    # Define the max duty cycle for u16
    MAX_DUTY = 65535
    
    r_duty = 0
    g_duty = 0
    b_duty = 0

    # Sector 1: Red to Green
    if val < (adc_r // 3):
        # Scale val to the 0 - MAX_DUTY range within this third
        relative_val = val * 3
        r_duty = MAX_DUTY - relative_val
        g_duty = relative_val
        b_duty = 0

    # Sector 2: Green to Blue
    elif val < (2 * adc_r // 3):
        relative_val = (val - (adc_r // 3)) * 3
        r_duty = 0
        g_duty = MAX_DUTY - relative_val
        b_duty = relative_val
        
    # Sector 3: Blue to Red
    else:
        relative_val = (val - (2 * adc_r // 3)) * 3
        r_duty = relative_val
        g_duty = 0
        b_duty = MAX_DUTY - relative_val

    # Ensure we stay in bounds and return integers
    return int(max(0, min(MAX_DUTY, r_duty))), \
           int(max(0, min(MAX_DUTY, g_duty))), \
           int(max(0, min(MAX_DUTY, b_duty)))

# Main Loop
while True:
    try:
        # Read the input voltage using 16-bit mapping (0-65535)
        raw = pot.read_u16()  

        # Map input to RGB
        rd, gd, bd = voltage_to_rgb_duty_values(raw)

        # Apply the duty cycles
        r_pwm.duty_u16(rd)
        g_pwm.duty_u16(gd)
        b_pwm.duty_u16(bd)

        # Small delay for stability
        time.sleep(0.02)
        
    except KeyboardInterrupt:
        print("Program stopped")
        # Turn off LEDs on exit
        r_pwm.duty_u16(0)
        g_pwm.duty_u16(0)
        b_pwm.duty_u16(0)
        break