Pre-merge river system questions

[TerryJC]

OK by me.

The Gate Valve seems to work OK and the erroneous reading could easily be nothing more than noise. Having said that, there appear to be two conditions where the code would return -1; the first is an exception caused by an OS error, (eg no A/D found or the I2C Bus not responding). The second is a negative value from the A/D. For the latter, the Potentiometer would need to be at the 0 V end of it's track AND the voltage is noisy.

That condition is perfectly valid in reality, so if we could show that was the case, and the voltage value wasn't very far away from the expected value of 0 V, we could simply accept it as meaning 0%.

Anyway, we should finish the migration before we try to go much further

[Penri]

As long as the valve control software treats it as a 0 (fully closed) then we do not need to do anything, I would say.

[hamishmb]

At the moment, the software ignores the -1 readings entirely - they don't happen very often IIRC, and even before we ignored them they didn't really cause any problems. Instead, the software goes with whatever the last good (not -1) reading was.