โก๏ธ pH Meter using Arduino Uno
โก๏ธ Arduino Project
- Measures pH value of liquid solutions in real-time.
- Uses a Gravity Analog pH Sensor for accurate readings.
- Displays measured pH value on a 16x2 LCD with I2C module.
- Calibration support for improved accuracy.
- Portable and low-cost design for water quality monitoring.
| Component | Quantity | Description |
|---|---|---|
| Arduino Uno | 1 | Main microcontroller board |
| 16x2 LCD Display | 1 | Alphanumeric display |
| I2C Module for LCD | 1 | Interface module to reduce wiring |
| Gravity Analog pH Sensor | 1 | pH probe with signal conditioning board |
| Breadboard & Wires | - | For connections |
| Power Supply (USB/5V) | 1 | To power Arduino |
- The pH electrode is dipped into a liquid sample.
- The probe generates a small voltage based on hydrogen ion concentration.
- The pH sensor board amplifies and conditions the signal.
- The analog output is fed into Arduino Uno (A0 pin).
- Arduino processes the input, applies calibration, and calculates the pH value.
- The result is displayed on the 16x2 LCD via I2C module.
| Arduino Pin | pH Sensor Board Pin |
|---|---|
| 5V | V+ |
| GND | G |
| A0 | Po |
| Issue | Possible Cause | Solution |
|---|---|---|
| LCD not displaying | Wrong I2C address | Scan I2C address and update code |
| pH values unstable | Probe not submerged properly / electrical noise | Use proper grounding and ensure probe is clean |
| Incorrect pH reading | Calibration needed | Adjust calibration value in code |
| Arduino not powering | Faulty USB cable / power supply | Replace cable or use 5V adapter |
- Water quality monitoring (aquariums, pools, tanks).
- Agriculture (soil and nutrient solution testing).
- Industrial process monitoring.
- Environmental research and wastewater treatment.
- Add temperature compensation for more accurate pH readings.
- Use OLED/TFT display for better UI.
- Wireless data logging using ESP32/Wi-Fi.
- Integration with IoT dashboards for remote monitoring.
| Parameter | Value |
|---|---|
| Supply Voltage (Sensor) | 3.3 โ 5.5V |
| Detection Range | 0 โ 14 pH |
| Accuracy | ยฑ0.1 @ 25ยฐC |
| Operating Temperature Range | 5 โ 60ยฐC |
| Probe Internal Resistance | <250Mฮฉ |
| Arduino Operating Voltage | 5V |
- ๐ pH Meter using Arduino Uno
- ๐ Arduino Projects
- ๐ Arduino IDE Download
- ๐ Arduino Uno Datasheet
- ๐ 16x2 LCD with I2C Interfacing Guide
- ๐ Interfacing 16x2 LCD with Arduino
This project is published on CircuitDigest โ your hub for electronics projects, tutorials, and resources.
Arduino pH Meter pH Sensor with Arduino Water Quality Monitoring Arduino Gravity Analog pH Sensor Arduino Uno LCD Display

