How to process audio WAV files in embedded systems

brumbarchris — Wed, 01 Oct 2008 09:35:36 +0200

This article shows how you may play WAV file created on your PC on an audio embedded system (comprising of a microcontroller, a DAC and a D class amplifier); it will detail the format of WAV files, show how you may extract raw data from them, how you translate it and how you should play it on. PC motherboards have both negative and positive supply voltage, therefore it is relatively easy for them to generate the dual polarity signal required to play a sound in a speaker. But how about audio embedded systems? Their overwhelming majorities (think about the number of mp3 players on the market!) have only positive power supply, so audio data has to be somehow translated to a positive interval.

Generating Analog Voltage with Digital Circuit (I)

brumbarchris — Tue, 16 Sep 2008 19:50:59 +0200

The purpose of this article is how to generate analog voltage with digital circuit.
Many times, designers are faced with the need of generating analogue voltage levels in purely digital circuits. Although the market provides today a very broad range of dedicated digital-to-analogue converters, putting such a device in the schematic has a negative impact on the overall cost of the system. There are however, cheap methods of creating the required voltage levels, and even of generating pseudo-analogue signals, using purely digital means.