Arduino as an ADC/DAC

The most recent Arduino runs at 16MHz, and can sample analog signals every 100 microseconds (about 10KHz) at 8 bit resolution. This is a reasonable audio sampling resolution, allowing us to capture and reproduce at least 5KHz, with processing time left over for doing DSP. In short, we could run an Arduino off a 9V battery and stick it in a guitar pedal.

An alternative use involving DAC would involve connecting via serial to the Arduino at a quick baud (say, 115200) and using each of the 6 PWM "analog outputs" as DACs, yielding 19200 baud per channel. With 8 bit audio, that's a 2.4KHz sample rate, or 4.8KHz for 4 bit audio. That is, we could use the Arduino to route low resolution 5.1 surround sound.

More on some of these possibilities here.