To be able to live measure PH i’ll try to hook up a PH probe to my arduino.
There are a few possible problems to be aware of: PH Probes need calibration. How often? Can it live measure during one round of fermentation and then calibration?
Does the material of the probe influence the ferment (fermentation + reactive metals don’t go well together)
Setting up the PH probe
Calibrating the analog sensor
I started by following this tutorial about setting up the PH probe.
My pinout is as follow:
V+ - Arduino 5V PO – Arduino A0 Gnd – Arduino Gnd
I short-circuit the BNC connector to stimulate a neutral PH7.
Then i used the following code and screw the POT until i got a value of 2,50v (2,51/2,51 in my case)
Now the resistance/input signal is calibrated.
Next i hooked up the PH probe and let it sit in distilled water (PH7)
I used the following code to read the measured PH value
After waiting for a couple of minutes to stabilize it gave me a reading of 8,75.
I checked with the digital PH meter which gave me a reading of 7,02.