Great Tutorial from TronixStuff about the less known Arduino AREF Pin. First: what is resolution?
We measure resolution in the terms of the number of bits of resolution. For example, a 1-bit resolution would only allow two (two to the power of one) values – zero and one. A 2-bit resolution would allow four (two to the power of two) values – zero, one, two and three. If we tried to measure ?a five volt range with a two-bit resolution, and the measured voltage was four volts, our ADC would return a value of 3 – as four volts falls between 3.75 and 5V.
What is AREF?
AREF means Analogue REFerence. It allows us to feed the Arduino a reference voltage from an external power supply. For example, if we want to measure voltages with a maximum range of 3.3V, we would feed a nice smooth 3.3V into the AREF pin – perhaps from a voltage regulator IC.?Then the each step of the ADC would represent?3.22 millivolts.
Read on this well detailed tutorial via [TronixStuff]
This entry was posted by Davide Gomba on Monday, December 13th, 2010 and is filed under ADC, AREF, Coding, English, sensors, tutorials. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.