The race is on.
Because I have yet to find a serial port on toon2, I decided to embark on a low-level approach to open up this toon, through JTAG.
As I already wrote in the Toon 2 hardware thread, the new toon has a set of non-populated pads which might fit a 10-pin header, even though we were told they were for some homekit chipset:
I switched on my opened toon2 and started measuring things on these pads. Two observations have emerged so far:
1: The ground connections match the pinout of a JTAG connector for the IMX6 SABRESD board.
2: Voltages measured on these pads correlate with what is to be expected from the rest of the same JTAG port.
Yesterday, the first half of my order of matching connectors for these pads arrived:
Tiny receptacles (Samtec MLE-105-02-G-DV-A), but they fit the pads and alignment holes like a glove. Connections for a homekit chipset indeed ... sure, if you say so ...
When the corresponding headers (Samtec FTMH-105-02-G-DV-A ) arrive, I'll solder these onto this toon, and get going with some JTAG sniffing. Not dissimilar from the approach I took a few years ago for the first model Toon.
Will keep you updated on any progress.