Arduino Mini Pro 3.3V 8Mhz - How to wire AREF voltage?

Using Arduino Microcontrollers
1

I am trying to use voltage reference diode LM385-2.5 with 68 k resistor to get the AREF voltage 2.5 V for Arduino Mini Pro 3.3V 8MHz. When I connect AREF pin to voltage reference diode the voltage drops to 1,.33 V because of the AREF input resistance 32 kohm and RAW Voltage 4.16 V (Li-Ion cell). What stabilizer, with minimum operational current, should I use?

Soldered wire to AREF pin (20):

2

Did you read the warning on the Arduino analogReference() page?

Don’t use anything less than 0V or more than 5V for external reference voltage on the AREF pin! If you’re using an external reference on the AREF pin, you must set the analog reference to EXTERNAL before calling analogRead(). Otherwise, you will short together the active reference voltage (internally generated) and the AREF pin, possibly damaging the microcontroller on your Arduino board.

3

@jremington

Yes, that's why I used the voltage regulator LM385-2.5 with 2.5 Volts for AREF.

4

You were quite clear as to be using 2.5V as external reference.

I think what @jremington is more concerned with is the following:

you must set the analog reference to EXTERNAL before calling analogRead(). . Otherwise, you will short together the active reference voltage (internally generated) and the AREF pin.

Since you did not show your code we do not know.

Willem.

5

try 10k instead of 68k