Microcontroller addict [Debraj] decided to make his own programmable sine wave generator ... sine lookup table, DAC, and control logic all into a single ten-pin package. [Debraj] uses AD9833 ...

Put this binary number into our DAC and we get a simple rising voltage out. A up-ramp wave. Now we feed the ramp into our inverting buffer circuit, and we get a beautiful sawtooth out the other side.