The project convert a standard residential water meter as an inexpensive industrial flow meter. To accomplish it, you need to remove the register of standard meter and adding a PCB to the top with a hall effect sensor to pick up the rotation of the internal impeller which has an embedded magnet that normally drives the register. The system was equipped a microcontroller AVR ATtiny2313 to controls the LCD, keypad, valve function, water metering and input power check.
“To use the Automatic water valve/meter, after connecting the water line and 12VDC from the pump engine, the operator simply presses the TEST FLOW button. The meter displays the GPM to insure that the water supply will be able to keep up. The GPM value is also used by the controller to determine if the flow is too low for accuracy or too high for potential damage to the flow meter. If it is out of bounds, the controller firmware will not allow the meter to enter the dispensing mode. When the button is pressed again the valve closes and the flow stops. Because the flow doesn’t stop immediately, the meter records how much water flows through the meter until it is stopped and records it. This value is subtracted from the next batch to compensate for different line pressure and other variations. The after flow volume is recorded after each cycle”, said Michael Githens, project designer.
Automatic Water Valve-Meter
Download Project Documentation (zip)