# main.py - MicroPython for Raspberry Pi Pico (reads soil sensor on GP26 / ADC0)
from machine import ADC, Pin
import utime

# === Configuration ===
ADC_PIN = 26        # GP26 -> ADC0, connect to sensor OUT
DIGITAL_PIN = 15    # GP15 -> digital wet/dry output from sensor (HIGH = wet)
PUMP_PIN = 16       # GP16 -> LED or relay driver (active HIGH)
VREF = 3.3          # Pico reference voltage (volts)
SAMPLE_INTERVAL = 1.0  # seconds

# Optional: software threshold for moisture_pct (0-100)
# If sensor provides digital wet/dry, you can ignore this and use DIGITAL_PIN state instead.
MOISTURE_THRESHOLD = 30.0  # percent (used to decide pump if digital pin not available)

# === Setup hardware ===
adc = ADC(ADC_PIN)             # ADC(26) for GP26
digital_in = Pin(DIGITAL_PIN, Pin.IN, Pin.PULL_DOWN)  # sensor's wet/dry output
pump = Pin(PUMP_PIN, Pin.OUT)
pump.value(0)  # ensure off initially

def raw_to_voltage(raw):
    # raw is 0..65535 for read_u16()
    # voltage = raw * VREF / 65535
    return (raw * VREF) / 65535.0

def voltage_to_moisture_pct(voltage):
    # Simple linear mapping: 0V -> 0%, VREF -> 100%
    # Replace with calibration formula if you have sensor-specific mapping
    return (voltage / VREF) * 100.0

print("Soil sensor monitor starting - ADC pin: GP{}".format(ADC_PIN))
print("Digital wet/dry pin: GP{}, Pump pin: GP{}".format(DIGITAL_PIN, PUMP_PIN))
print("Sampling every {:.2f} s".format(SAMPLE_INTERVAL))
print()

while True:
    raw = adc.read_u16()   # 0..65535
    voltage = raw_to_voltage(raw)
    moisture_pct = voltage_to_moisture_pct(voltage)

    # digital state from sensor: HIGH = wet (moisture >= threshold set in the chip)
    digital_state = digital_in.value()

    # Decision: use digital pin if present; else use analog threshold
    if digital_state == 0:
        # sensor says DRY -> turn pump ON
        pump.value(1)
        pump_status = "ON"
    else:
        # sensor says WET -> turn pump OFF
        pump.value(0)
        pump_status = "OFF"

    # Uncomment to use analog-only decision (if you prefer)
    # if moisture_pct < MOISTURE_THRESHOLD:
    #     pump.value(1); pump_status = "ON (analog)"
    # else:
    #     pump.value(0); pump_status = "OFF (analog)"

    # Print human-readable monitoring output
    print("Raw: {:5d} | Voltage: {:.3f} V | Moisture: {:.1f}% | Digital wet: {} | Pump: {}"
          .format(raw, voltage, moisture_pct, "YES" if digital_state else "NO", pump_status))

    utime.sleep(SAMPLE_INTERVAL)