Uno R4 Wifi DAC for variable control of +10 -10v NE5523op-amp

[treedweller]

Hello all, I'm new to the world of MCU's so bear with me please.

I'm trying to control a laser galvo with the R4 DAC pin. So far I've set up an NE5532 as non-inverting with +-15v input and 5v signal, 2.5v reference and simple feedback resistance. The circuit swings from +10 to -10 quite nicely when using a 5vdc power supply, but when I use the DAC pin everything goes haywire.

I've tried analogReadResolution and analogWriteResolution in 8, 10 and 12 bit, mapped a slide pot to A0 in order to vary output voltage from 0 to 5v but the DAC output signal is very noisy. I've done away with the pot and set the DAC output to a range of steady values yet the problem persists.

My Arduino question is - is the arduino DAC just noisy in general, or am I missing some important code?

Do I need to filter the DAC output? I'd have thought it would be a clean signal considering theres no waveform involved.

Here's my sketch, as simple as it is. Thanks in advance

#include "analogWave.h"

void setup() {
  analogWriteResolution (12);
  analogReadResolution (12);
  // put your setup code here, to run once:

}

void loop() {
  int qq = analogRead (A5);
  int ww = map (qq, 0, 4095, 0, 4095);
  
  analogWrite (DAC, ww);
  
  // put your main code here, to run repeatedly:

}

[JohnLincoln]

The output of the DAC is generally quite steady, except that there is a 'glitch' that occurs whenever it is updated.

Your code will be particularly noisy as you are updating the data to the DAC very frequently.

Here are some oscilloscope traces taken from an Uno R4 Minima running your code.
The blue trace is the input voltage on pin A5.
The yellow trace is the DAC output on pin A0.

Here is a constant 2.5V input on a faster time base, you can see each glitch:

There was a smilar topic at: hairy-output-on-r4-dac.