Measure pH, ORP, EC or salinity with an Arduino or Raspberry Pi

Isolated ISE Probe Interface for pH

Measure pH

  • Measure pH with temperature compensation (0 - 14 pH) 🧪
  • Raw mV (-1024 - 1024 mV)
  • Temperature in Celsius/Fahrenheit (-55 - 125 °C) with optional temperature sensor
  • Electrically Isolated
  • The same hardware can measure ORP or any other mV based probe, only the library is different

What it is

An I2C sensor that can read a pH probe. Attach a waterproof temperature sensor for temperature compensation with the attached connector. The firmware on the device provides two calibration options, single or dual point.

The board uses the Qwiic Connect System, an easy-to-use, polarized, push-to-fit connector. No more mistaken connections or soldering header pins. Adafruit calls these connectors STEMMA QT.

All boards have a conformal coating to help protect against moisture, corrosion, and short circuits.

Electrical Isolation

When different probes are connected to the same controlling device, they can cause interference. The environment also causes interference due to ground-loops or other electrical noise like pumps. Electrically isolating the probe can help to prevent these problems.

Using it

There is plenty of documentation on the specification, setup, and use of the sensor.

The Arduino IDE, PlatformIO, and Particle.io library is in their respective library managers. Any Arduino compatible board will work.

A python and rust library is available for the Raspberry Pi and a MicroPython library is available for any compatible board.

Arduino C++

Raspberry Pi Rust

Raspberry Pi Python or Micropython


Buying it

The sensor comes with one Qwiic wire, you can buy extras if needed. There are 3 types of wires to choose from; Qwiic to Qwiic used to connect a Qwiic board to another Qwiic board, Qwiic to male headers, and Qwiic to female headers.

It also comes with a dust cap, hex nut, washer and rubber seal for the BNC connector.

Knowing the temperature isn’t really required for an accurate measurement, but it’s useful to know and you can easily connect a waterproof temperature probe to the board.

Shop


Support, Documentation, and Questions

Sensor Circuit Datasheet

pH Probe Datasheet

Waterproof Temperature Sensor Datasheet

If you have questions, find a bug, or have any suggestions, go to this project’s GitHub page and submit an Issue or Pull Request. Or you can send an email to [email protected].