This is a very well documented build, and could be a great addition to any workbench. Apparently the builder added the meter to a 0-30 VDC stabilized power supply, pictured above, to charge batteries. All the schematics, PCB layouts and .hex files are available on the site.
This multimeter was designed to measure output voltage and current in a PSU, where the current sense shunt resistor is connected in series with load at the negative voltage rail. It needs only one supply voltage that can be acquired from main PSU. An additional function of the multimeter is that it can control (switch on and off) an electric fan used to cool the main heatsink. The power threshold at which the fan switches on can be adjusted using One Touch Button Setup.
Voltmeter + Ammeter LCD pane – Link
The first digital voltmeters and the birth of test automation – Link