This liquid controller project can be used to measure & supply exact amount of liquid like water, petrol, kerosene, juice, cold-drinks etc. It uses simple set up for the hardware – an AT89S52 Atmel microcontroller, motor relay, 16×2 LCD and three buttons for input. The system uses time value rather debit counter to measure and control liquid amount.
Before usage, it needs a reference time value which is taken by measuring 100% value. For example, we sets 100% = 1 Liter. To get this reference time value, press ‘UP & DOWN’ button simultaneously to start liquid supply and measuring the time. When 1 liter of liquid is completed, press ‘STOP’ button and the reference time value is saved.
Once the reference value is stored you can pour 3 litters by setting value of 300% or on LCD and push the start button. When liquid is completed poured, it stops automatically. If you need 0.5 litters you can set 50% on LCD using up/down button. For accuracy, a right reference value and constant pump flow is required. Source code and schematic.