Water Level 2.0

Note

🌟 Welcome to the SunFounder Facebook Community! Whether you’re into Raspberry Pi, Arduino, or ESP32, you’ll find inspiration, help ideas here.

✅ Be the first to get free learning resources.
✅ Stay updated on new products & exclusive giveaways.
✅ Share your creations and get real feedback.

👉 Need faster updates or support? Click [here] join our Facebook community
👉 Or join our WhatsApp group: Click [here]

Kit purchase

Looking for parts? Check out our all-in-one kits below — packed with components, beginner-friendly guides, and tons of fun.

Name	Includes ESP32 board	PURCHASE LINK
ESP32 Ultimate Starter Kit	ESP32 WROOM 32E +	BUY
Universal Maker Sensor Kit		BUY

Course Introduction

In this lesson, you’ll learn how to build a simple water level indicator using an analog water level sensor and 8 LEDs with the Arduino Nano ESP32.

As the water level rises, more LEDs light up to visually display the current level in real time.

Note

If this is your first time working with an ESP32 project, we recommend downloading and reviewing the basic materials first.

Required Components

In this project, we need the following components:

SN	COMPONENT INTRODUCTION	QUANTITY	PURCHASE LINK
1	Arduino Nano ESP32	1
2	USB Cable	1
3	Breadboard	1	BUY
4	Wires	Several	BUY
5	Water Level Detection Module	1
6	Resistor	1KΩ	BUY
7	LED	Several	BUY

Wiring

Common Connections:

Water Level Detection Module
- A: Connect to A0 on the ESP32.
- G: Connect to breadboard’s negative power bus.
- V: Connect to 3.3V on the ESP32 Extension Board.
LEDS
- Connect the LED cathode to a 1KΩ resistor then to the negative power bus on the breadboard, and the anode to the D2~D9 on the ESP32.

Writing the Code

Note

You can copy this code into Arduino IDE.
Don’t forget to select the board(Arduino Nano ESP32) and the correct port before clicking the Upload button.

// LED pin array (Dx labels for Arduino Nano ESP32)
const int ledPins[] = {D2, D3, D4, D5, D6, D7, D8, D9};
const int numLEDs = 8;

// Water level sensor analog input pin
// Use an ADC-capable pin on ESP32
const int sensorPin = A0;   // On Nano ESP32, A0 is mapped to a valid ADC pin

void setup() {
  Serial.begin(115200);

  // Set all LED pins as output
  for (int i = 0; i < numLEDs; i++) {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW);
  }
}

void loop() {
  // Read the water level sensor value (ESP32 ADC range: 0~4095)
  int sensorValue = analogRead(sensorPin);

  Serial.print("Water level analog value: ");
  Serial.println(sensorValue);

  // Map the analog value to number of LEDs (0~8)
  // Adjust 0~1900 according to your actual sensor output range
  int level = map(sensorValue, 0, 1900, 0, numLEDs);
  level = constrain(level, 0, numLEDs);

  // Turn on LEDs according to the water level
  for (int i = 0; i < numLEDs; i++) {
    if (i < level) {
      digitalWrite(ledPins[i], HIGH);
    } else {
      digitalWrite(ledPins[i], LOW);
    }
  }

  delay(500);  // Delay before next update
}