Z-Turn GPIO add-on
This board brings out the GPIO pins found on the CN2 connector and routes them through 74LVCH245 buffers out to normally-sized pin headers.
Project repo: https://code.hackerspace.pl/emeryth/zturn_addon/
Details
Schematic
Power
The board features two ways of powering the buffers, selectable by J1 jumper pins:
- EXT 3.3V - uses the 1117 linear regulator on the PCB, which is connected to the Z-turn's 5V supply
- INT 3.3V - uses 3.3V supplied by the Z-turn board
Of course you can connect your own supply to one of the VCC pins if you want to (after removing the jumper).
I/O Pins
The board features five 8-bit bi-directinal buffers - 74LVCH245. The direction can be set individually for each buffer.