The device I intend to build has one job: sound an alarm at the slightest sign of trouble. I'll leave it to Lassie to let me know when Timmy is stuck in the well, but that should alert as line blockage. We have voltage, current, and duration data available. Let's extend the timing component to track time of day. Now we need to set the time, or do we? Not really, what is needed is when the night-time cycle begins. A pump running overnight can be a sign of trouble. Add a button, press it when the night cycle should begin. (If we power up at noon, the clock would have the right time.) Now that there's a button, it can be used to silence the alarm signal. If there was an alarm, it would be useful to know why. A few LEDs to show a binary code should suffice. The power source can be a unused 5V phone charger. A battery backup is not really necessary, since a power outage will also shut down the power hungry pump. That was easy.

Scope creep

There is quite a lot of unused potential, even on an 8k Z8. I know, add a bluetooth adaptor! There's an HC-05 laying around, unused. That'll do. Since there is now bi-directional data transfer, there should be read-modify-write for threshold values. If the remote device has graphics capability the pump's operating current can be dispalyed as a graph, a valuable diagnostic tool.

Let's go!

Hold on, that part is not available until ... When???

Redesign a little bit.

Let's use a piezo beeper in place of the 555 and speaker. Forget the TCXO, use a standard oscillator. Only 4 left in stock? I plan to build more than that just for the beta test. Keep looking.

More scope creep

A conversation with a neighbor led me to the posibility of calculating the water depth in the well shaft based on the pump's performance. I may have to invite Math.h to the party.