Measuring pH using Dormant Labs PH Module V2 and Arduino

Here is a quick setup guide to start measuring ph using the Dormant Labs PH Module V2.

You will need:

• PH 4 and 7 Calibration Solution
• A Arduino
• Dormant Labs PH Module V2 (available here)
• A PH Probe
• Three small cups, two to hold the two calibration solutions, and one to hold water for rinsing the ph probe 
• 4 dupont male to female cables

First connect the ph probe to the ph module

Then

• Connect V+ to Arduino 5v or 3v pin
• Connect GND to Arduino GND pin
• Connect SDA to Arduino SDA pin(For UNO it is A4)
• Connect SCL to Arduino SCL pin (For UNO it is A5)
• Attach USB to Arduino

Get the source code from here:

https://gist.github.com/rezahussain/bb7715534688d8dc0520

and upload it using the Arduino IDE. If you do not have the arduino IDE get it from the arduino site.

After uploading the code, open the serial monitor and you should see output like this:

You are now ready to calibrate your ph probe.

Fill one cup with PH 4.0 calibration solution, one with 7.0 calibration solution, and a third with water.

Remove the cover from the ph probe and rinse it with water.

Then dip the probe in the 4.0 solution, swirl it around for a little bit, and write down the value you see for the avgPhVolts. For me, I saw 0.95v.

Rinse the ph probe in the water, then dip in the 7.0 calibration solution and write down what you see for avgPhVolts.

Here are the values I got:

Now I replace the volt4, volt7, and calibrationTempC, then re-upload to the Arduino.

After re-uploading your probe is now calibrated! The serial monitor of the arduino IDE will show the correct information. Edit the code as you like now.