I am still confused of the operation of a curve tracer (for a tunnel diode) I know the classical tracer is to show the I-V characteristic of a BJT transistor, using a scope. I think the curve tracer for a diode, including the tunnel diode, also needs a scope. The scope's X-axis is voltage V, and Y-axis is current I.

Now my very first I-V curve plotting experiment does NOT use any scope. I just vary the voltage source to the tunnel diode with a protecting, series current limiting resistor. I use a manual, two push button presses to adjust the voltage value. I use a DMM to measure the voltage across the diode, and another DMM to measure the current through the diode, and also through the resistor. After all the measurements, I use the Excel worksheet to plot the I vs V curve.

The problem of using the above manual, adj PSU, and voltage and current DMM is that it is tedious to make the not too accurate DMM measurements. And it would be even more tedious to find the series/external resistance and inductance to avoid the switching/jumping over the NDR region, as described by the GE's 1962 TD User Manual, in my BlogSpot post below.

tunneldiode.blogspot.com/2020/11/blog-post_24.html.

Ah, jogging and supper time! See you later. Cheers.

The pcf8951 DAC/ADC is only 8 bit resolution. So I am not sure I need higher resolution ADC, such as 10 bit MCP3008, 12 bit MCP3208, or even higher.

Okay, I'll explain but I have to do something first and I suspect that when I'm done it will be time to go to bed there ...

nothing urgent. You can do it in two weeks, which is what I need to sort all the ADC, DAC stuff. I just found two more old PCF8951 ADC/DAC's in my junk box. Usually I need two or three same modules for swap testing or troubleshooting. Good night. Cheers.

OK, I will comment in your blog - tunneldiode.blogspot.com/2020/11/blog-post_24.html.

I have appended my comments in you blog also to my answer to your question in CD.