# Experiment A: Analog Sensor Reading
# Reads a voltage from a potentiometer (simulating an analog sensor)
# and prints the value to the Serial Monitor.

import machine
import utime

# 1. Initialize the ADC pin (GP26 is ADC0 on Pico)
adc = machine.ADC(26)

# 2. (Optional) Initialize an LED pin for visual feedback
led = machine.PWM(machine.Pin(16))
led.freq(1000)  # Set PWM frequency to 1kHz

print("🔌 Experiment A: Analog Sensor Started!")
print("📊 Turn the potentiometer knob in Wokwi and watch the values change.")
print("------------------------------------------------")

try:
    while True:
        # 3. Read the raw ADC value (0-65535 for Pico's 16-bit ADC)
        adc_value = adc.read_u16()
        
        # 4. Convert the raw value to a voltage (0.0 - 3.3V)
        voltage = (adc_value / 65535) * 3.3
        
        # 5. (Optional) Use the value to control LED brightness
        led.duty_u16(adc_value)  # Direct mapping
        
        # 6. Print the values to the Serial Monitor
        print(f"ADC: {adc_value:5d}  |  Voltage: {voltage:.2f}V")
        
        # 7. Short delay for readable output
        utime.sleep_ms(200)

except KeyboardInterrupt:
    # 8. Safe exit: turn off LED and print message if code is stopped
    led.duty_u16(0)
    print("\n✅ Experiment safely stopped.")