Documentation

// Water Level Sensor - Arduino Example (GPIO-powered to prevent corrosion)
// S -> A0, + -> D7, - -> GND

const int powerPin = 7;
const int sensorPin = A0;

void setup() {
  Serial.begin(9600);
  pinMode(powerPin, OUTPUT);
  digitalWrite(powerPin, LOW);    // sensor off between readings
}

int readLevel() {
  digitalWrite(powerPin, HIGH);   // energize the probe
  delay(20);                      // let the reading settle
  int value = analogRead(sensorPin);
  digitalWrite(powerPin, LOW);    // power off - no electrolysis
  return value;
}

void loop() {
  int level = readLevel();        // 0-1023

  Serial.print("Raw: ");
  Serial.print(level);

  if (level < 100) {
    Serial.println("  (dry)");
  } else if (level < 450) {
    Serial.println("  (low water)");
  } else {
    Serial.println("  (HIGH water!)");
    // trigger your pump/alarm/notification here
  }

  delay(3000);                    // check every 3 seconds
}

# Water Level Sensor - ESP32 MicroPython Example (GPIO-powered)
# S -> GPIO 34, + -> GPIO 25, - -> GND

from machine import ADC, Pin
import time

power = Pin(25, Pin.OUT, value=0)   # sensor off between readings
adc = ADC(Pin(34))
adc.atten(ADC.ATTN_11DB)            # full 0-3.3V range

def read_level():
    power.value(1)                  # energize the probe
    time.sleep_ms(20)               # settle
    value = adc.read()              # 0-4095
    power.value(0)                  # off - no electrolysis
    return value

while True:
    level = read_level()

    if level < 400:
        state = "dry"
    elif level < 1800:
        state = "low water"
    else:
        state = "HIGH water!"

    print("Raw: {} ({})".format(level, state))
    time.sleep(3)

#!/usr/bin/env python3
# Water Level Sensor - Raspberry Pi + ADS1115 Example (GPIO-powered)
# S -> ADS1115 A0, + -> GPIO 17 (pin 11), - -> GND
# Install: pip3 install adafruit-circuitpython-ads1x15

import time
import board
import busio
import RPi.GPIO as GPIO
import adafruit_ads1x15.ads1115 as ADS
from adafruit_ads1x15.analog_in import AnalogIn

POWER_PIN = 17

GPIO.setmode(GPIO.BCM)
GPIO.setup(POWER_PIN, GPIO.OUT, initial=GPIO.LOW)

i2c = busio.I2C(board.SCL, board.SDA)
ads = ADS.ADS1115(i2c)
ads.gain = 1
channel = AnalogIn(ads, ADS.P0)

def read_level():
    GPIO.output(POWER_PIN, GPIO.HIGH)   # energize the probe
    time.sleep(0.02)                    # settle
    volts = channel.voltage
    GPIO.output(POWER_PIN, GPIO.LOW)    # off - no electrolysis
    return volts

try:
    while True:
        volts = read_level()

        if volts < 0.3:
            state = "dry"
        elif volts < 1.5:
            state = "low water"
        else:
            state = "HIGH water!"

        print("Signal: {:.2f} V ({})".format(volts, state))
        time.sleep(3)

except KeyboardInterrupt:
    print("Stopped by user")
finally:
    GPIO.cleanup()

# Water Level Sensor - Pico MicroPython Example (GPIO-powered)
# S -> GP26 (ADC0), + -> GP16, - -> GND

from machine import ADC, Pin
import time

power = Pin(16, Pin.OUT, value=0)   # sensor off between readings
adc = ADC(26)

def read_level():
    power.value(1)                  # energize the probe
    time.sleep_ms(20)               # settle
    value = adc.read_u16()          # 0-65535
    power.value(0)                  # off - no electrolysis
    return value

while True:
    level = read_level()

    if level < 6000:
        state = "dry"
    elif level < 28000:
        state = "low water"
    else:
        state = "HIGH water!"

    print("Raw: {} ({})".format(level, state))
    time.sleep(3)