Does anyone know of a good tutorial for the Beaglebone Black RPU? I tried the one from http://boxysean.com/blog/2012/08/12/first-steps-with-the-beaglebone-pru/ but that doesn't seem to work.
On Sunday, April 6, 2014 8:34:08 PM UTC-5, Sungjin Chun wrote: > > Programmable Realtime Unit. > http://processors.wiki.ti.com/index.php/Programmable_Realtime_Unit_Subsystem > > You can use this processors for realtime tasks. > > > On Mon, Apr 7, 2014 at 10:14 AM, Stacy Cottles <[email protected]<javascript:> > > wrote: > >> Eric, I apologize for my ignorance but what is the pru? >> >> On Sunday, April 6, 2014 6:18:27 PM UTC-5, Eric wrote: >>> >>> I might be inclined to use the pru for this and just setup the pru as >>> escentially a hardware counter. There are likely ways to do so with timers >>> and interrupts and such but being more of a hardware guy than software I'm >>> inclined to use a more hardware approach and use the pru as a counter that >>> gets read every so often. the software for that then is escentially a >>> driver that creates /dev/rpm. >>> >>> Eric >>> >>> >>> On Sun, Apr 6, 2014 at 3:43 PM, Stacy Cottles <[email protected]> wrote: >>> >>>> Thanks Eric for the suggestion. I'll have to figure out the inductive >>>> circuit to use. Do I have to use interrupts or is there something better >>>> for capturing the signal from the pickup? >>>> >>>> >>>> On Sunday, April 6, 2014 1:51:07 PM UTC-5, Eric wrote: >>>> >>>>> an inductive pickup around the sparkplug wire should get you a nice >>>>> pulse each time the spark plug fires but remember the phases of a 4 >>>>> stroke >>>>> engine (intake - piston down intake valve open, compression - piston up >>>>> valves closed, power - piston down valves closed, exhaust - piston up >>>>> exhaust valve open). The spark plug only fires every other revolution. >>>>> Once you have the pulse from the inductive pickup it should be buffered >>>>> to >>>>> provide a nice square wave pulse of uniform voltage such that it's easy >>>>> for >>>>> the processor to use and not a potential hazard to the processor due to >>>>> spurious high voltages (cooking the buffer circuit while in development, >>>>> sorta ok.... cooking the processor, well not so much!) >>>>> . from there it's just software and the incrementing of a counter >>>>> with each pulse. >>>>> >>>>> >>>>> >>>>> >>>>> On Sun, Apr 6, 2014 at 6:33 AM, Stacy Cottles <[email protected]>wrote: >>>>> >>>>>> I am building a web-controlled lawn-mower. I would like to be able to >>>>>> read the RPM off the gas-engine. I would prefer to piggy-back off of the >>>>>> spark-plug if possible since it fires faster as the engine spins faster. >>>>>> Just started on this but would love suggestions. I have a Beaglebone >>>>>> Black >>>>>> running Angstrom and I am using NodeJS to control GPIOs. >>>>>> >>>>>> -- >>>>>> 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]. >>>>>> >>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>> >>>>> >>>>> >>> -- >> 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] <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- 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]. For more options, visit https://groups.google.com/d/optout.
