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This web blog is established for collecting useful information about building prototype with arduino or other applications. This page shuld help a designer with very basical technical cognition to build a working model or a prototyp for his design concept. We find prototyp or working model an excellent tool to test concept and understand it's usage in real condition (not only fantasy in mind). It's ofter very hard to realize every functions of a design concept. However it's our goal here to make this task easier.

What should be always keeped in mind is that we are not engineers and it's not our goal to design a perfect electron programme control. We are designers who are more willing to understand the users through prototype testing.

This web-site is still under construction and more information shall be collected. :)

Oct 12, 2011

How to use AREF of Arduino

The aref works like this...

When you do analogue to digital conversion the arduino board uses the 5V supply as a reference. this means that any voltage between 0 and 5v is represented as numbers between 0 and 1024. If the signal you are measuring never reaches 5V it is possible to change  the reference  to an internal 2.5 v source and this divides the space between 0 and 2.5v in 1024 steps effectively doubling the resolution. If this still doesn't work for you then you can ask the processor to use an external voltage applied to aref. if you find a super stable 1V refernce source this will give you 1milli volt resolution for the ADC. this is used only in special applications because at that resolution the noise becomes a big issue etc etc

switching reference voltage requires adding a few lines of C code to your arduino code.

===========
cbi(ADMUX, REFS1); //clear REFS1 bit (0)
cbi(ADMUX, REFS0); //clear REFS0 bit (0)
===========

Reference:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1139161553/3#3

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1142283743
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