The PRU cookbook is nearing completion (more accurately, I'm running out of summer).
Here's a link https://markayoder.github.io/PRUCookbook/ I'm happy for any feedback you can give me. --Mark On Thursday, June 28, 2018 at 8:45:00 PM UTC-4, Neilh wrote: > > Ok thanks. I see I was think SHARED_RAM between the ARM-A8 and PRU0 and > its actually shared between ARM PRU0 and PRU1. Ahhhh-lightbulb---hhhhh > Many thanks for the evolving cookbook and detailed explanation- I have got > a little lost at times digging through the manual - gosh I want to read all > the PRU sections - I'd have paid gold 4weeks ago when I started using the > PRUst!. > If it becomes a book I'll be first in line to buy it :). > The PRUs are a cool part of the BBB - and now I've got it working appears > pretty simple. > > > On Thu, Jun 28, 2018 at 12:59 PM Mark A. Yoder <mark.a...@gmail.com > <javascript:>> wrote: > >> Neilh: >> I've worked up some examples[1] for a PRU Cookbook that might help. I'm >> taking a similar approach to what you did, but I'm using DRAM0. It >> shouldn't be hard >> to switch to shared RAM. >> >> --Mark >> >> [1] >> https://markayoder.github.io/PRUCookbook/05blocks/blocks.html#_controlling_the_pwm_frequency >> >> >> On Wednesday, June 27, 2018 at 5:36:13 PM UTC-4, Neilh wrote: >>> >>> Oops I got it - it was sizing a pointer and not the struct. >>> >>> I'd be interested in anybody's comments on the use of the SHAREDRAM >>> approach as it makes for a very simple one way api. I'm partly publishing >>> this as a tutorial for anybody else - but its my first try at the PRU. >>> >>> Here is the logic anlayzer output from the Saleae 8 Channels mapping of >>> PRU0 to GPIO P9_25 ...P8_12 >>> There is an increasing pulse count chn0, and then fixed 1hz, 2hz... on >>> subsequent channels >>> >>> >>> >>> On Wed, Jun 27, 2018 at 2:13 PM Neil Hancock <neilh...@gmail.com> wrote: >>> >>>> Oops - you are right, I'll update my comments >>>> >>>> Here is the code that is allocating the SHAREDRAM - though I'm still >>>> hazy as to how mmap() works in BBB mapping the SHAREDRAM >>>> >>>> #define AM33XX_DATARAM0_PHYS_BASE 0x4a300000 >>>> #define AM33XX_DATARAM1_PHYS_BASE 0x4a302000 >>>> #define AM33XX_PRUSS_SHAREDRAM_BASE 0x4a310000 >>>> #define SHARED_RAM_SZ 16 /* grab 8*4 bytes or 8 words */ >>>> >>>> volatile uint16_t *shared_dataram; >>>> >>>> /* Define an API to be calleable from JS -still needs work */ >>>> >>>> void bbbio_ppm_api(struct channels_s *channels){ >>>> memcpy((void *)shared_dataram,(void *)channels,sizeof(channels)); >>>> } >>>> >>>> void bbbio_ppm_init() { >>>> /* Allocate shared memory pointer to PRU0 DATARAM */ >>>> int mem_dev = open("/dev/mem", O_RDWR | O_SYNC); >>>> volatile void *shared_dataram_init = mmap(NULL, >>>> SHARED_RAM_SZ, >>>> PROT_READ | PROT_WRITE, >>>> MAP_SHARED, >>>> mem_dev, >>>> AM33XX_PRUSS_SHAREDRAM_BASE >>>> ); >>>> shared_dataram = (uint16_t *) shared_dataram_init; >>>> } >>>> >>>> void bbbio_ppm_cleanup() { >>>> munmap((void *)shared_dataram,SHARED_RAM_SZ); //njh guess at releasing >>>> it. >>>> } >>>> >>>> #ifdef MAIN_LOCAL >>>> void main() { >>>> unsigned int sec_i, chnl_j; >>>> unsigned int offset; >>>> struct channels_s channels; >>>> volatile uint16_t *shared_dataram2; >>>> >>>> bbbio_ppm_init(); >>>> uint16_t ppm =60;//actually >>>> >>>> offset = 0; >>>> channels.chn[offset].sr =ppm; >>>> printf("shared_datara2 = %p, offset=%d At init Read:", >>>> shared_dataram,offset); >>>> shared_dataram2 = (uint16_t *) shared_dataram; >>>> for(chnl_j=0; chnl_j<8; chnl_j++) { >>>> printf(" %04d", *shared_dataram2); >>>> shared_dataram2++; >>>> if (0x3 ==(chnl_j & 0x3)){printf(" ");} >>>> } >>>> printf("\n"); >>>> >>>> ppm =0; >>>> for(chnl_j=0; chnl_j<8; chnl_j++) { >>>> channels.chn[chnl_j].sr=ppm; >>>> ppm += 60; >>>> } >>>> //Fut - wait for ack from PRU and then init shared ram >>>> >>>> //while (1) >>>> { >>>> ppm=60; >>>> for(sec_i=0; sec_i<8; sec_i++) { >>>> channels.chn[offset].sr +=ppm; >>>> //memcpy((void *)shared_dataram,(void *)&channels,sizeof(channels)); >>>> bbbio_ppm_api(&channels); >>>> printf("Writing %04d Read:", ppm); >>>> shared_dataram2 = (uint16_t *) shared_dataram; >>>> for(chnl_j=0; chnl_j<8; chnl_j++) { >>>> printf(" %04d", *shared_dataram2); >>>> shared_dataram2++; >>>> if (0x3 ==(chnl_j & 0x3)){printf(" ");} >>>> } >>>> printf("\n"); >>>> sleep(1); >>>> } >>>> } >>>> bbbio_ppm_cleanup(); >>>> } >>>> >>>> #endif //MAIN_LOCAL >>>> >>>> On Wed, Jun 27, 2018 at 1:33 PM Dennis Lee Bieber <wlf...@ix.netcom.com> >>>> wrote: >>>> >>>>> On Wed, 27 Jun 2018 12:18:27 -0700, Neil Hancock >>>>> <neilh...@gmail.com> declaimed the >>>>> following: >>>>> >>>>> > with 8*int16 (or 32bytes). >>>>> > >>>>> Pardon? >>>>> >>>>> int16 is 2-bytes, 8*2 => 16 bytes >>>>> >>>>> >Initially I tried 8*int32 (64bytes) but could only sucessfully use the >>>>> >first 5*int32(40bytes >>>>> > >>>>> Similarly, int32 is 4-bytes, 8*4 => 32; 5*4 => 20 >>>>> >>>>> >>>>> >>>>> -- >>>>> Wulfraed Dennis Lee Bieber AF6VN >>>>> wlf...@ix.netcom.com HTTP://wlfraed.home.netcom.com/ >>>>> >>>>> -- >>>>> 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 beagleboard...@googlegroups.com. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/beagleboard/pvs7jdpvq34jft17pkpeljrk5p0scj487r%404ax.com >>>>> . >>>>> 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 beagleboard...@googlegroups.com <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/a90eb811-c902-4a20-96fa-31e1b03abb5a%40googlegroups.com >> >> <https://groups.google.com/d/msgid/beagleboard/a90eb811-c902-4a20-96fa-31e1b03abb5a%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> 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. 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