This is a simple square wave generator for STM32F4 µ-controllers. It currently only supports the STM32F429I-Discovery board. It generates waves out to 100Khz, with reasonable accuracy (< 1% error) out to about 50KHz.
The major problem at this point is that the STM32F4289I Discovery board uses the two DAC output pins to drive the on-board LCD, so there's no analog output available. So all you get is a square wave via toggling a digital pin. Hopefully either a different board or an external LCD will fix this.