December 20, 2013

Safely using precision voltage references with AREF

After the introductory post about AREF earlier this month, we've found another interesting tutorial by Telford Dorr. He takes the subject further by demonstrating how to create a more precise voltage reference with a TL431 shunt regulator to create the required reference voltage, whose output is fed through an op-amp which is used to protect the input on the microcontroller if you accidentally misuse the AREF functions in your sketch. 

In his own words:

Should the AVCC switch accidentally close, the Aref pin will be pulled up to AVCC, the op amp output will swing to its negative rail (assumed to be 0 vdc here), and the 4.7k resistor will limit the current to little over a milliamp, saving the processor from destruction.

It's a useful yet simple form of increasing accuracy and protection for your Arduino's analogue work, so to learn more visit Telford's tutorial page. And for more, we're on twitter and Google+, so follow us for news and product updates as well.

If you've been looking for an approachable, easy to read book to learn about Arduino, or as a gift for someone else - you can't go past "Arduino Workshop -  A Hands-On Introduction with 65 Projects” by John Boxall.

Arduino Workshop takes the reader from having zero knowledge about the Arduino platform, electronics and programming and leaves them with the know-how and instructions on everything from blinking an LED, to robotics, wireless data, cellular communications, Internet connected systems and more. For more information including a sample chapter and table of contents, visit the book page

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