1/20/04 Update
It has been a little while since I updated the controller pages. Work continues, and progress is being made. The ORP is now breadboarded, and the code for it is written. The ORP measures 0-530 ORP, and can be used to turn on and off any of the relays (good for ozone users). The probe, unfortunately, is NOT a DIY project...these things are precision semipermiable membranes and AgCl electrodes. So, I am using a premade Pinpoint orp probe on the unit. I have a couple of shots of the now finalized hardware...this is what is going to be in the final unit.
I can imagine everyone freaking out about the ratsnest of wires on the breadboard. This entire circuit will most likely be able to be made about the size of a VCR tape. I believe that this is going to be a 4 layer board, so it will not be makeable at home. If I have time after I get the internet module working, I may layput a double sided board for people that are interested in making their own, but It is going to be rather large. Another picture showing the LCD better
Here is the new ORP circuit up and working, the probe has a salt solution in the cap to keep the membrane moist, and it happens to read 290mv ORP. I really have no way to carry this down to my tank, so I calibrated it using known input voltages from my DC power supply (per MBeldings instructions). Once again, a big thanks to MBelding for the design of the ORP hardware (as well as the pH hardware).
