This is the first circuit I made using my Basic Stamp. The instructions it uses to generate the waves are PWM for triangle and sawtooth; FREQOUT for the sinewave; and TOGGLE for the squarewave. The triangle and sawtooth waves aren't very good looking, but the sine and square are just perfect.

Be sure to Download the PBasic Program and Word document with theory, the document is in spanish, so if you don't know spanish, you kan start learning.