This is my second article about building a DIY digital audio recorder. Inspired by this microcontroller audio project [via], I set out to build a simple digital recording device. I chose Texas Instrument's MSP430 microcontroller for this project because it's fast (16 MHz), it's cheap ($1), and it's very low power. Read the first part here
This week we'll progress towards a digital audio recorder by generating simple tones with the MSP430 microcontroller. We'll use the MSP430's pulse-width modulator to generate an audio waveform, and clean it up with a simple low-pass filter. The signal won't be strong enough to drive a speaker directly, but it'll work great with a cheap set of powered PC speakers.
Next week we'll expand on this basic circuit to play audio recordings from SD memory cards
Read on to learn more about generating audio with a microcontroller.