I’m inclined to put up [nuxie1]’s function generator how-to because he also submitted a very nice Design Challenge entry. The generator is based on the cheap XR2206 IC which will genera… ...

This document describes how to implement an interrupt driven multifunction generator on C8051 devices using the on-chip digital-to-analog converter (DAC). Some of the features covered include: Four ...

If you have a modern function generator on your bench it is quite likely to contain a direct-digital synthesis circuit that creates arbitrary waveforms using a microprocessor controlled DAC.