The water pump controller is intended to replace the wiring based water pump system of typical camping vans with a bathroom and a kitchen and addresses some problems these systems can have.
In such a system, water taps are usually equipped with switches that signal the need for water as soon as the tap is slightly opened so that a pump can be activated to pressurize the pipes.
The controller has six inputs so that each tap (e.g sink in the kitchen, sink in the bathroom, toilet flushing, shower in bathroom, external shower) can use a dedicated input. It has another input for a high pressure switch that would turn off the pump if the pressure rises when all taps are actually closed.
The main feature is a timer that can give an reminder using a buzzer when the water is running for an untypically long period and automatically switch off the pump at some point as well. When the switch off time was reached the buzzer signal can help to indicate which switch is still active.
For testing the circuit, the outputs (including the pump output) can be connected to LEDs or as in the test board to a 7-segment display. In the test board the pump output corresponds to the top segment. The inputs can be connected to DIP switches. The clock should be set to 32768 Hz (2^15 Hz). The reset signal should provide a power-on reset and optionally a manual reset that might be handy for testing. In the minimal setup, the last three bidirectional I/O pins should be connected via separate resistors to GND. Connecting them directly to GND should be okay as well for a quick test. The pins can be outputs that should only be driven to low in this case, but do not connect them directly to VCC. The other I/O pins can be left open or connected to GND to avoid floating pins. The connection to GND can be done directly or via pull-down resistors to plan ahead for more tests with additional circuitry.
The first test is about enabling the pump while not making use of the timer:
The second test is to verify the high pressure switch:
A simple test for the timer with default values:
Testing the configuration feature requires additional external circuits. Please refer to the testing section of the README of the github project (https://github.com/fahek/water-pump-controller-tto5#more-advanced-tests).