Lab-grade digital pH and ORP circuit

For laboratory, hydroponics, education, and aquariums

Available with lab-grade pH probe. Connects directly to your device (Arduino, Raspberry Pi, or embedded) - no other parts required. Our open-source software makes measuring fast and easy.

Beyond pH

Includes temperature compensation, with built in sensor. Can be used with Oxidation Reduction Potential(ORP) , and other ion-selective electrodes. (Nitrate, Potassium, etc) probes.

This module can be used with any probe with a BNC connection. The I2C interface can communicate with nearly any microcontroller.

Fully tested on Arduino, Raspberry Pi, and STM32

Output pins are labeled on the board, as follows:

• +VCC: 2V – 5V power input
• SDA: I²C digital output
• SCL: I²C digital output
• GND: Ground

Arduino wiring

Raspberry Pi wiring

Installing software

Arduino: From the Arduino IDE: Sketch → Include Library → Manage Libraries → select Anyleaf

C++: Download Anyleaf.cpp and Anyleaf.h from the C++ Github link below, and place them in your project directory

Python: Run sudo apt install python3-scipy, then pip3 install anyleaf. Ensure I2C is enabled.

Example code, and driver source

• Arduino and C++

• Python

• Rust

A minimal Arduino example

#include <Anyleaf.h>

PhSensor ph_sensor;

void setup(void) {
    Serial.begin(9600);

    ph_sensor = PhSensor();

    ph_sensor.calibrate_all(
        CalPt(0., 7., 25.), CalPt(0.18, 4., 25.)
    );
}

void loop(void) {
    Serial.print("pH: "); Serial.println(ph_sensor.read());

    delay(1000);
}

A miminal Raspberry Pi Python example

import time
import board
import busio
from anyleaf import PhSensor, CalPt, OnBoard

def main():
    i2c = busio.I2C(board.SCL, board.SDA)
    delay = 1  # Time between measurements, in seconds
    phSensor = PhSensor(i2c, delay)

    phSensor.calibrate_all(
        CalPt(0., 7., 25.), CalPt(0.18, 4., 25.)
    )

    while True:
        print(f"pH: {phSensor.read(OnBoard())}")

        time.sleep(delay)


if __name__ == "__main__":
    main()

Datasheet

Regular calibration is required for accurate measurements. The official drivers support 2 or 3 point calibration. 2 point is sufficient for hydroponics, aquarium, or brewing use. 3 points, or 2 carefully chosen points are required for sufficient accuracy for lab use.

Module specifications:

• Dimensions: 50 × 25 × 17(height) mm
• Weight: 14 grams
• pH precision: 0.01, with a suitable sensor
• pH Range: 0 - 14
• Digital precision: 16 bit
• Input voltage: 2 - 5V
• Mounting screws: 4 × M3, 6mm len (included)
• I2C address: 0×48 or 0x49 (selectable)
• Sensor interface: BNC male (Accepts BNC female sensors)
• Power consumption: 1.375 mA
• UPC / GTIN: 860004179009

pH probe specifications:

• Design: Double junction glass hydrogen-sensitive electrode
• Dimensions: 155 × 12 mm
• Weight: 24g
• Measurement range: 0 - 14
• Outer tube material: Plastic
• Bulb shape: Spherical
• Cable length: 1 m
• Connector: BNC female
• Temperature range: 0-80°C

ORP probe specifications:

• Design: Double junction glass ORP electrode
• Dimensions: 155 × 12 mm
• Weight: 24g
• Measurement range: ±2000 mV
• Outer tube material: Plastic
• Bulb shape: Spherical
• Cable length: 1 m
• Connector: BNC female
• Temperature range: 0-80°C

Compatible with the Mycodo Environmental Monitoring and Regulation System. If you're using a Raspberry Pi, this is a simple way to get it running with a GUI, charts, and logging. Follow the installation instructions on that page, and add AnyLeaf pH as an input.

Also available on Tindie.