Dangerous Prototypes Open Source Hardware

Another small cosmetics changes, cleaned next to the inputs. Name is changed to Touch Sensing old v1.2 mini

You are connecting EARTH to GND with low impedance line. You may fry your iron this way.

I tested the gs8552, and randomly selected a few pieces in the alternative experiment. The offset voltage dispersion is relatively large, ranging from 15uv to 6, 7uv. The bias current is relatively stable and relatively small at the level of tens of pa. There is also 600uv at the low end of the output. There is a negative power supply-0.6v should have no effect. The quality control is not very good, the experiment was abandoned at that time, and others saw that reuse may be the reason for the low cost.

It looks like possible substitute. I will check it out when it comes to me. I has some slight difference in offset voltave and bias/offset currents, but I think that they are not critical at all.

Look here for substitutions: https://github.com/valerionew/unisolder-notes#equivalent-parts-in-bom

It won't be any time soon, although the code should be pretty much the same as on my optical sensor board. The only difference will be that I will use internal comparators in the MCU instead of sending a signal to the IR transmitter and checking if it is received by the receiver, as now I do.

But given the fact that both mine an minkok's pure analog versions work, I don't see much reason of doing something else soon.

You can just "add a C at input".  Who's care! ... What I mean is, Do not do that !!! There is latest revision.