from machine import Pin, ADC, PWM
from time import ticks_us, ticks_diff, sleep

# =====================================================
# TASK C - Raspberry Pi Pico + Encoder + Potentiometer
# =====================================================

# -----------------------------------------------------
# MOTOR DRIVER (L293D or similar)
# -----------------------------------------------------

pinM1 = Pin(10, Pin.OUT)     # IN1
pinM2 = Pin(11, Pin.OUT)     # IN2

pinPWM = PWM(Pin(12))        # ENABLE / PWM
pinPWM.freq(1000)

# -----------------------------------------------------
# ENCODER
# -----------------------------------------------------

# WOKWI ROTARY ENCODER
pinENA = Pin(14, Pin.IN, Pin.PULL_UP)   # CLK
pinENB = Pin(15, Pin.IN, Pin.PULL_UP)   # DT

# -----------------------------------------------------
# WHEN USING THE REAL LAB ENCODER:
# Uncomment and connect the REAL encoder pins here
# -----------------------------------------------------

# pinENA = Pin(14, Pin.IN, Pin.PULL_UP)   # Encoder Channel A
# pinENB = Pin(15, Pin.IN, Pin.PULL_UP)   # Encoder Channel B

# -----------------------------------------------------
# POTENTIOMETER
# -----------------------------------------------------

pot = ADC(Pin(26))

# -----------------------------------------------------
# ENCODER VARIABLES
# -----------------------------------------------------

PPR = 12          # Pulses per revolution
dA = 360 / PPR

t0 = ticks_us()
RPMs = 0

# -----------------------------------------------------
# ENCODER INTERRUPT FUNCTION
# -----------------------------------------------------

def measureENC(pin):

    global t0, RPMs

    t1 = ticks_us()
    dt = ticks_diff(t1, t0)
    t0 = t1

    if dt <= 0:
        return

    # ---------------------------------------------
    # Direction detection
    # ---------------------------------------------

    if pinENB.value() == 1:
        direction = -1
    else:
        direction = 1

    # ---------------------------------------------
    # RPM CALCULATION
    # ---------------------------------------------

    RPMs = direction * (60_000_000 / (PPR * dt))


# -----------------------------------------------------
# INTERRUPT
# -----------------------------------------------------

pinENA.irq(trigger=Pin.IRQ_RISING, handler=measureENC)

# -----------------------------------------------------
# MAIN LOOP
# -----------------------------------------------------

while True:

    # ---------------------------------------------
    # READ POTENTIOMETER
    # ---------------------------------------------

    potValue = pot.read_u16()     # 0 → 65535

    # ---------------------------------------------
    # PWM VALUE
    # ---------------------------------------------

    pwmValue = potValue

    # ---------------------------------------------
    # MOTOR DIRECTION
    # ---------------------------------------------

    pinM1.high()
    pinM2.low()

    # ---------------------------------------------
    # FOR REVERSE DIRECTION IN LAB:
    # Uncomment these lines
    # ---------------------------------------------

    # pinM1.low()
    # pinM2.high()

    # ---------------------------------------------
    # MOTOR SPEED CONTROL
    # ---------------------------------------------

    pinPWM.duty_u16(pwmValue)

    # ---------------------------------------------
    # FOR REAL LAB MOTOR:
    # Uncomment if minimum PWM is needed
    # (some motors don't move at low PWM)
    # ---------------------------------------------

    # if pwmValue < 12000:
    #     pwmValue = 12000

    # pinPWM.duty_u16(pwmValue)

    # ---------------------------------------------
    # SERIAL MONITOR / SERIAL PLOTTER
    # ---------------------------------------------

    print(-150, 150, RPMs)

    # ---------------------------------------------
    # FOR LAB DEBUGGING:
    # Uncomment these lines
    # ---------------------------------------------

    # print("Potentiometer:", potValue)
    # print("PWM:", pwmValue)
    # print("RPM:", RPMs)

    sleep(0.02)