On Wednesday, October 5, 2016 at 12:11:18 PM UTC-4, beezerlm wrote: > > Well I have obtained a BBB along with the PRU cape. I soldered the Jtag > header on and I purchased a blackhawk XDS100v2 JTAG Emulator. I istalled > CCSv6 and I have completed the PRU labs 1 through 4 - found here: > http://processors.wiki.ti.com/index.php/PRU_Training:_Hands-on_Labs#Hardware > > > I am trying to figure out where to go from here. Libpruio looks > promising, but I would like to take the path that would offer the best > overall determinism & latency characteristics for reading encoder input and > controlling IO accordingly. I would think the best case scenario would > be to program the PRU directly and skip linux altogether. This may be > overkill for my current project, but it seems like it would be useful for > more demanding applications I may cross in the future. >
Here is a simple project which might help you with "where to go from here": https://www.hackster.io/Greg-R/pru-pid-motor-speed-controller-with-beaglebone-green-ccb805?ref=search&ref_id=remoteproc&offset=1 This project uses one of the Encoder modules which the PRU accesses via its OCP master. The PRU has its own encoder, but it has only one pin wired out, and in this project that pin is used in PWM mode. The encoder function must be quadrature (2 wires), so even if the PWM was not being used it would have to use an external encoder. The project uses RemoteProc which you have already encountered in the Labs. RemoteProc will take care of loading the firmwares as well as provide a simple two-way communications channel between the PRUs and user-space. The most expensive component (besides the Beaglebone) is the motor-encoder which you can get from eBay for about $20. At the very least you can look at the C code for the PRU firmware and you can see how the external Quadrature Encoder module is accessed from the PRU. Regards, Greg -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/d9a210a0-944c-4b8d-9338-40318c20f591%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
