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Comment by tdicola | Hacker News Reader

This looks neat for people that want a cheap board to hack on embedded Linux. However for serious control of signal generation, acquisition, PWM, servos, etc. you really don't want to be running a multitasking OS. Something like the Beaglebone Black, with its dedicated 200mhz programmable units in addition to embedded Linux, is much more interesting for hackers and makers IMHO.

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The PRUs are a seriously underrated feature of the BBBs. It's like having another two computers over 50x as fast as my ZX Spectrum that can run independently, and provide completely realtime output.

> The PRUs are a seriously underrated feature of the BBBs.

Speak English, please.

PRU-> programmable real time unit

BBB-> BeagleBone Black

The BBB has an extra dual core processor that runs at 200Mhz. It is interesting because it is like the processor they teach you about in your intro to computer architecture classes, every instruction is a single cycle instruction. Since it is a co-processor(not running an OS but controllable from the BBB's OS) and execution of instructions is deterministic, it is a good choice for running hard real time code.

Thanks.

Agreed - we used the PRUs for high speed data acquisition (~3.4msps.). What would have normally required a lot of outboard logic ended up being almost all software. Very much an underrated feature, although the Learning curve is not so great though for anything non-trivial.

Do you have a blog or somewhere where I can get more information on your experience using the PRUs ?

Thanks !

I'm curious what you do with them. Sage Devices doesn't seem to have a lot of info available but Bolt says y'all are doing "Home Energy Management". What in home energy management requires ~3.4msps?

I kind of wish the PRU's were Cortex-M0 or something that can be targeted with GCC. That said, they are a very nice idea.

I'm currently using the Zynq for a project and it's basically the extreme of the idea. FPGA's are kind of horrible in other ways though, such as the 30 minute build times and power inefficiency.

I considered writing a LLVM backend for the PRUs, but put it aside while I wait to see if the rumors of a TI provided compiler pan out.

Agreed - after working with some bit modulation for a whole lot of LEDs and with the PRU unit on the BeagleBone, I don't think I'd want to use a big multitasking embedded system for finer-tuned stuff.

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