Dave wrote: > I disagree. > > If you want a killer product for the BeagleBone Black, you need to toss > the EPP port concept entirely and have the BeagleBone Plug into the > Breakout board - similar to a cape. Yes, I mostly agree with this. What I had in mind was to put an 8-bit plus control signals interface in the adapter so that it could connect to my existing boards, as a first step. Then, I can change the firmware on my boards to handle a much faster protocol between the ARM and my FPGAs. Another plan might be to make an FPGA board specific for the Bone, but what do I do with all the inventory I already have, here?
The problem is in a mid-performance servo system, the PRU may not be fast enough to read encoders and produce PWM for the servo drives. Since there are two PRU units, this may not actually be true, but I still imagine that a completely software encoder counter would take at least several us, maybe tens of us to complete for 4 or more axes, so that would limit the maximum encoder count frequency. I have often run into the 1 MHz default count rate on my boards. So, a 100 KHz count limit would be at least a concern. Also, using the PRU to generate PWM, I'd imagine the timing resolution would be a us or so, at best. I have 25 ns timing resolution with my PWM controller. So, FPGAs still have something to offer. Just some comments to throw out there. Jon ------------------------------------------------------------------------------ Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_apr _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
