Arduino and Ph Probe

[brad]

I am a software developer, and want an Arduino controlled reef. LED Lighting with dimmers, Tunze Streams, a pH probe, a thermometer and possible some relays and other sensors. I am not sure if I should build a Hydra or work off an existing Arduino (probably a mega).

The pH probe is the hardest for me to understand. The only documentation I can find is on the hydra site, and it involves a magic fairy and four lawn gnomes. My local garden center sells lawn gnomes, but I can't find a magic fairy (mouser part #?), and have no idea how to hook them up to the probe and Arduino board.

[ronsonol]

I have a ethernet shield installed on top of my mega. On top of that I have a PH/ORP shield made by practicalmaker. Google that. Was very easy to get running.

[disc1]

The probe gives you a voltage signal in the mV range. You'll need to amplify that and read it on either the analog inputs on arduino or using a separate ADC.

Aside from that, the rest is cleaning up the signal. Calibration can be handled with hardware but is probably easier to do with software. Measure two points and build a line. The response from the probe is linear wrt pH.

[mcgyvr]

Love the gnome/magic fairy part.. :)
A good sense of humor is getting much harder to find now.

Simply googling "arduino ph shield" gives TONS of information.
Time to step over the line for a while to "hardware designer" or pick up a pre-made shield