Short update:

I have improved the software so now you can select either of the two commonest tunings for the keyboard i.e. G/C or D/G. You can select the one you want on startup and also change the tuning while the device is in operation by pressing the upper rightmost three keys simultaneously. It is a bit like a Tesla car, load in a software upgrade and your (unchanged) hardware suddenly performs better.

I have uploaded this version of the code (Version 37).

Also the original red plastic DigiGurdy has to my surprise been featured in the current edition of Prog magazine - as in Prog Rock. Aug/September 2019.

I intend to go through all the 3D print files one more time then will also post them up here.