Interactive retail kiosks are everywhere. We all recognize the pervasiveness of these devices - whether you're rushing through a self checkout machine at the hardware store or testing speakers at a department store. In a previous articles, we covered how to create interactive buttons on embedded LCD touch screens and how to play audio on embedded devices. Lets put this all together to build an interactive audio kiosk!
Sometimes you have an embedded project that needs to play audio. Maybe you just need to make a beep, in which case a simple piezo speaker and a square wave will work, but other times you'll need to play actual audio, like voice or music. In that case, you need to use a Digital to Analog Converter (DAC) to generate the stored waveforms. The other question is how to store these waveforms; the easiest way is to use the WAV file format. This tutorial will discuss the basics of WAV files and how to play these with the provided code, using the onboard DACs of the MCF5441X processor found on Netburner's MOD5441X and NANO54415 modules.