Analog Reference on Nano IOT max. Outpul Volatge

Hello, I just logged in first time with an issue I am not able to find the mistake. I would like to use the external 5V signal via USB as a reference for the AREF Pin.
I have closed the bridge on lower side of the PCB. My Sketch is defining the analog output on A0 with following settings:
analogWriteResolution(12);
analogReference(AR_EXTERNAL);
Just for test reason I am generate a triangle signal in a loop.
while (i <4095) {
analogWrite(VolumeOutPin,i);
i++;
}
Looking at the output Pin using an oscilloscope the max. Voltage is 2,95V, not the expected 5,0V.

I hope someone is able to help me,
Bernd

What type of Arduino do you have?
You can't have a reference voltage greater than the Arduino's working voltage, other you might destroy it.

You can't get an analogue output on a analogue pin. These pins are input only. The analogWrite produces only a PWM signal, and only certain pins are capable of generating a PWM signal, the exact pins depend on the actual Arduino you are using.

Hello Grumpy, thanks for your information. The Nano board is able to provide an analog output on Pin A0 using an internal DAC. Unfortunatly max. DC 2,96V. I have to use an external circuit to scale the output.
I thougt i could apply an externel higher Voltage on Aref, this is so far i know now, not possible.

regards Bernd

What Nano boards? There are quit a few Arduinos that answer to that description. This is why I asked you what type it is.

Now given the extra information that an analogue output is available on the Nano you have has a D/A that narrows it down to about four Nanos. So we still do not know what sort of Nano you have, there are still things some of your remaining Nanos can do / can't do.

So please mention the specific Nano board you have.

The Board I am using is the Nano 33 IoT, sorry for confusion.

Bernd

So this page Data sheet

Says it only has a 10 bit D/A converter, so you can't set the resolution to 12 bits and expect to get a 12 bit output.

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