DIY Controller (Atmel based)

[mark]

Kwirky, once you get them running, sounds like a cheap little controller you could market to fellow reefers.

Robw, I was looking for the output for figuring the slope/intercept for a pH probe awhile back (was hooking to a datalogger) and got this e-mail from American Marine (AMI):
"After proper calibration the probe will generate 59 mV per each unit of positive pH and the opposite will be negative mV. Example pH 7.0= 0 mV; a ph of 8.0=59mV a pH of 6.5= -30mV Good Luck...Lou Dell/AMI"