I have a problem while using arduino Due with DAC AD420.
I followed the shematic and the code exposed here High-accuracy 16 bit DAC for Arduino / shaduzLABS and I want to read the analog output of the DAC so I connect the out to the A0 pin on my arduino. I measure output voltage of the DAC with an oscilloscope.
Here's the problem :
When I disconnect the link between OUT DAC and A0 arduino the measurement is good, but when I connect the link there's is a voltage drop (it's about 0.5V and the zero voltage is shifted down !
If someone can give me some explanation about this fact, thanks a lot.
When you link the A0 to the output of the D/A you are connecting the output of an op amp with what looks like a 5V or so DC offset on it.
This is giving an over voltage signal into the Due and causing the problem. This could also damage your Due.
Measure the output from that op amp again and look at the DC offset from it.
Thanks for your reply Grumpy_Mike. Well in fact the max output voltage measured after the op amp is 3.2V so it's suitable for analog inputs of arduino Due (max 3.3V).