PRU

Enabling the PRU

To enable the pru (and set up p9_12 and p9_11 to work as i/o) run i2c_bitbang/pru_sw/setup_pru.sh.

This script applies the device tree overlay and loads the kernel module for the PRU

Testing if the PRU is frozen

Sometimes (more often than I would like) when developing software for the PRU will freeze up, requiring a reboot. Run the "blink" program to see if the pru is responding. If the program exits successfully, then it's still working

I've only seen this happen with code I haven't gotten working completely. This problem always seems to go away after I have the PRU code completely function.

Debugging the PRU

There exists a nice (as in better than nothing) debugger for the PRU, called prudebug. Follow their instructions to install it:

http://sourceforge.net/projects/prudebug/

Mapping DDR memory to PRU

Here's an example of mapping the ddr memory to PRU, so you can have access to large amounts of data. http://hipstercircuits.com/beaglebone-pru-ddr-memory-access-the-right-way/