So my final year project for electronics engineering diploma (2010), was to design and implement a digital multimeter using Atmel 8051 MCU+16x2 LCD and a development board that was supplied by the university.

Schematic Diagram for the external setup of the meter


Schematic Diagram for the Development board(Open source)

cuicuit diag

Source code: written in Keil Uvision 3 (program has few bugs but works 100%)