We have touch input! First successful test:

The chip is a TI ADS7843 clone (even table references in it's datasheet match TI's datasheet, and not it's own numbering -- had me scratching my head, until I found the TI datasheet, and then it made sense :).

Had to write driver from scratch, to use hardware SPI (otherwise there aren't enough pins). MOSI/MISO/CLK are shared with the ILI9341 display driver. While at it, added support for differential mode (code I could find used bitbanged SPI and single-ended mode). The code is currently a frakking mess, but once cleaned up, it'll be on github.

So, the $22 Digole can be replaced by a $7 generic module (running ucglib, a much nicer graphics lib, too!). Getting closer to the ~$13 mark, which makes much more sense for this device.

Edit - initial code here: https://github.com/spapadim/XPT2046