Adafruit Industries Adafruit Industries MCP4725 Breakout Board
Your microcontroller probably has an ADC (analog -> digital converter) but does it have a DAC (digital -> analog converter)??? Now it can! This breakout board features the easy-to-use MCP4725 12-bit DAC. Control it via I2C and send it the value you want it to output, and the VOUT pin will have it. Great for audio / analog projects, such as when you can't use PWM but need a sine wave or adjustable bias point.
Adafruit Industries MCP4725 Breakout Board