With a Beaglebone Black, I want to use the MMC, USB and occasionally an LCD cape. The I/O for peripherals will be entirely SPI based, so I want to use some GPIO pins as chip selects.
Looking at the P8/P9 header mappings, it looks like P8 is almost entirely used up with MMC and LCD signals, which leaves me P9 for GPIO. What pins are other group members using for GPIO and why?
First do you plan on using HDMI, or an LCD via SPI ? Most of those pins used by HDMI can be easily recovered. Ive also been told you can reclaim a few from the eMMC too, but have not tried it personally.
Secondly, you need to do a bit of reading / understanding of what you’re working with. No different from anyone else who has been working with these boards a while. Read the SRM , and TRM( technical reference manual of the AM335x processors ).
Then use google, and the search feature of these forums. There is a lot of useful information out there. You just have to look for it.
Scratch that. Mode 7 is my friend