Including sound in a project makes anything cooler but the Arduino has pretty severe limitation when it comes to audio. The Tone library (https://www.arduino.cc/en/Reference/Tone) is simple but it can only play one tone at a time. Then the internal memory space (https://www.arduino.cc/en/Tutorial/Memory) in an Arduino Uno is limited to 32k which is less then a second of sound and that is only if you have no code :) Finally there is no true DAC (https://www.arduino.cc/en/Reference/AnalogWrite) on the Uno. Most code uses PWM (https://www.arduino.cc/en/Tutorial/PWM) to produce an "analog signal" but if you run that through a speaker you hear some pretty nasty harmonics.
What I want to demo do is a simple system for getting clear sounding audio samples. To do this we will combine a standard SD card
and we will see if it all works together :) This project provides a lot of flexibility for audio projects plus it shows how to add a easy DAC to any Arduino project. Also the R-2R DAC is a nice demonstration of the trade off between circuit simplicity and I/O usage.
