PRU availability

Are both the PRU units free resources on the BBB?
Does the ethernet connector use them or any other built-in hardware devices?
Any capes take advantage of them?

Check out the SRM and it will tell you what pins are free.

Not all pins are accessible.


I was interested if any BBB drivers for the onboard peripherals need a PRU core to work.
Are they both always unused? I think they are both available for end users to use, but I wasn't sure.

There is a lot of PRU activity in th ecommunity and some good resources. There are some links to the PRU here



Both are fully available to users. Nothing in the standard images consume any resources on the PRUs (except for the shared usage of the pins as Gerald mentions).

The beaglelogic and pruspeak examples from Google Summer of Code might be useful starting points for your development.