This multimeter was build as an addition to power supply unit by Zbyszek.
This unit uses ATMEL Atmega8 microcontroller which reads voltage (0…30V with resolution of 10mV), current (0…99A with resolution 10mA) and displays information on LCD. All you need is to mount multimeter to PSU module according to this diagram. Do not connect to voltages more that 50V as this may be dangerous for adapter and you. Author uses this multimeter for charging of RC Li-Pol cells. For this purpose you need to flash desired firmware which displays capacity passed to load, this way you can see how much cells are charged.