Cheap pH meter hack for Arduino | overSKILL. I needed a pH sensor for my AquaTank project, opened google, searched a bit and was stung by the prices “Holy ****, thats expensive!!” 109$ Sparkfun 35$ Atlas-scientific 29$ Absolute Cheapest – DFrobot Still not cheap enough for me And then I found this thread : Well I’ll explain shortly – a guy found a 8$ pH pen meter on DX and we want to hack it to get the pH on our arduinos, I succeeded. pH meters in general: A pH probe is zeroed on 7 and generates about 0.06 volts (depends on the probe) for each pH unit. for a value of 8 the voltage will be 0.06 volts and for a value of 6 it will be -0.06.
Hacking the cheap meter: The thread was dead until someone got a meter that had the part number on the main chip (the rest got custom labeled chips) that’s inside the meter. Then I said why not order the pH meter, some shift registers and put in line diodes in order to rectify the current and everything will be dandy I did. but what a MESS !!
The result: Arduino ph probe interface - Sparky's Widgets. Project description If you've ever wanted to make a pH meter out of an Arduino or RaspberryPi or to find the pH of a solution, needed to interface a pH probe or wanted to make your own pH sensor. This is an ideal project and tutorial for you. The idea of this project is to interface common inexpensive Marine/Lab/Horticulture pH probes with the Arduino style prototype boards that are very common these days. we will also learn about how to interface common chemical reactions and what Ion Selective Probes are such as the very common pH electrode. These types of probes have a very high impedance signal that poses a few design issues, thankfully we have modern ICs which take care of most of these concerns.
Taking that and a few other considerations into account we can still produce a cost effective and accurate interface that even someone new to electronics can build themselves. Lets Get Started So what is a pH electrode anyway . And the other in a low concentration of . Its Sodium Ions I swear.