I purchased a PH Probe from ebay that has a BNC connector and a PC board. I found the following site that describes the pinout: https://forum.arduino.cc/index.php?topic=336012.0
I am connecting 3.3v and ground to the PH Probe, and also the output to my A3 pin. When reading the values, I am seeing 4088-4087 constantly.
The probe I am using is the:
Based on the first link I provided, I assume that I should be seeing a value of 511 to represent a PH of 7.
Any thoughts as to what I might be doing wrong?