Since AREF pin of arduino pro mini 3.3v is connected to 0.1uF capacitor and this pin isn't present at breakout , it's not possible to get voltage of AREF pin by physical test ( through multi-meter ) . I will use INTERNAL 1.1V as reference , hence I need to know how much voltage I will get for INTERNAL 1.1V reference at AREF pin , hence I need a code to measure voltage of AREF pin .
Pls help me .
hence I need to know how much voltage I will get for INTERNAL 1.1V
I'm going to guess that chose that name because the internal reference voltage is 2.8V.
hence I need a code to measure voltage of AREF pin .
The AREF pin is an input pin. You should KNOW how much voltage you are putting in.
On the 32-pin surface mount packages the AREF pin is number 20 counting counter-clockwise from the PIN 1 mark. On the 28-pin MLF package it's pin 17. Use a fine point meter probe.
Search the forum for "secret voltmeter". This is a method of reading the value of Vcc assuming that the internal voltage reference has a value of 1.1V. If you have a known value of Vcc, you can then back-calculate how much AREF is.
mnhpias:
Since AREF pin of arduino pro mini 3.3v is connected to 0.1uF capacitor and this pin isn't present at breakout , it's not possible to get voltage of AREF pin by physical test ( through multi-meter ) . I will use INTERNAL 1.1V as reference , hence I need to know how much voltage I will get for INTERNAL 1.1V reference at AREF pin , hence I need a code to measure voltage of AREF pin .Pls help me .
It IS possible to use A-ref on a Pro Mini: see this page Reddit - Dive into anything
It describes how to wire pin 20 to one of both reset pins after cutting the tiny track to it. I did it and it works perfectly, just use a very precise cutter and magnifying glasses.
FYI, you don't have to do the external hardware fix if you call out analogReference(DEFAULT); under your void setup loop. I was about to do the hardware fix when I found this out.