Do you mean the 1x10 row of unpopulated header? On this plank all pins are in use, so they can’t really be taken for other functions. It’s not impossible, with caveats such as only using the pins that are inputs to the RS3232 (not driven).
This unpopulated breakout of all Bus Pirate signals is common to all planks, and is just there for my (and your) development pleasure. Testing, debugging, or breaking out pins you want to use for another function.
For RS232 side breakout we included a screw terminal thing like this in the cable kit. However, breaking out those signals is a good idea. This is the first plank where we have this concept of “internal and external” signals.
It seems like we have a couple updates for a rev2 board:
- breakout RS232 signals
- Double throw switches to select pinout