I have just purchased several of the SwitchDoc 4 channel A to D converter boards.
I find the documentation is a bit too sparse. In particular, the (4) analog ports are apparently specified to be "Grove" ports. But, Grove ports as shown as having two analog inputs each - for a total of 8 inputs. This is very confusing.
Having the schematic (which I cannnot find) would go a long way toward clarifying this and other issues.
There does not seem to be anything proprietary on this board, so releasing the schematic would seem harmless.
Is the schematic or other improved explanation available?