Adjust Watering time as function of solar charging

[epccs]

Irrigation should be a function of the solar power received. At present, the firmware runs the valve and counts flow pulses from a flow meter while the state machine cycles. It is crude but seems to work. Each garden zone gets watering cycles for an amount of runtime_sec every delay_sec after morning, when the day-night state machine loads the solenoid state machine from EEPROM. The solenoid states begin to cycle after a delay_start_sec that is used to offset each zone's operating time (e.g., starts the operation out of phase.)

https://github.com/epccs/Irrigate7/tree/master/Solenoid

I am thinking about measuring the Amp hours (more likely mA*hours) and using that to adjust the irrigation time somewhat. The idea is that the plants drink more water as the sun lines up with the photovoltaic.

The soil will buffer some water near the surface, but it only takes a short while for the drip emitter to dump more than capillary action can hold. Depending on soil structure the water soon sinks below the root zone for my garden plants. Once the water has gone too deep, it is lost. Dripping ten cycles once per hour for a tenth of the day's usage keeps the water near the surface where the plants can sip on it.

The plants drink the most when the sun is overhead, and they are doing the maximum activity, and less in the morning and evening. The battery charge is also a function of how overhead the sun is why not use that information to add watering time.