I'm currently traveling and only have access to basic parts (soldering iron, an arduino nano and a breadboard!) but I'm able to buy parts from local suppliers. for a project I need to be able to create some waveforms and verify the output of the circuit (I tend to only do it for about 10 to 100Hz, so nothing high frequency!).
I think I can use an instrumentation amplifier followed with a summing amplifier to adjust DC offsets (add or remove) and another inverting amplifier to get the original signal, which is finally fed into the MCU ADC input and sampled as fast as possible, then displayed on the PC using a serial monitor program.
I'm having some doubts about the audio output of my PC however. I'm not sure if it's bipolar (i.e goes below ground as well) or if it's unipolar with a certain amount of DC offset? I did some googling but couldn't find anything and I'm not sure how I can verify that.
The signals will be created using this website:
which gives quite a lot of options for the output waveform except anything for DC offset!
obviously the ADC on the arduino works only in the 0-5 range and is unipolar. I try to take a picture of my current schematic and upload it, in case that's relevant information.