I use *__delay_cycles()* on the PRU to get accurate timing. Each cycle is 5 ns.
Here [1] is an example of passing data between the PRU and the ARM. Try googling *pthread tutorial,* there appear to be many examples. I'm still voting for pthreads. --Mark [1] https://markayoder.github.io/PRUCookbook/05blocks/blocks.html#_controlling_neopixels_through_a_kernel_driver On Thursday, February 18, 2021 at 11:27:48 AM UTC-5 [email protected] wrote: > I think if I could just find how to read the clock on the PRU with C, I > can probably take it from here. And of course, it needs to be giving me > milliseconds. From what I read the main clock functions don't work below > seconds. > > > On Thursday, February 18, 2021 at 10:37:59 AM UTC-5 Mark A. Yoder wrote: > >> Have you tried starting a pthread that sleeps for 20 ms and then it stops >> the read? >> >> On Thursday, February 18, 2021 at 10:35:04 AM UTC-5 >> [email protected] wrote: >> >>> Mark, >>> >>> I use usleep a lot but in this case I don't want to pause. I want to >>> keep reading the sensors for N milliseconds. I do pause between reads >>> using usleep(20000) to create a 20ms delay between sensor reads. I >>> started with a routine that essentially counts up the amount of time by >>> estimating how long the sensor read routine takes plus the fixed delay time >>> between sensor reads and accumulating this value in a while loop until it >>> reaches the 'stop value' that is approximately the time the valve needs to >>> stay on. But this is sketchy and I don't like it. Lots could go wrong. >>> >>> In essence, I'm looking to interrupt the sensor read procedure after N >>> milliseconds pass. >>> >>> Walter >>> >>> >>> On Thursday, February 18, 2021 at 10:29:44 AM UTC-5 Mark A. Yoder wrote: >>> >>>> Walter: >>>> It's good to hear you have the PRUs working. I still think if all >>>> you need is millisecond timing the PRUs are over kill. >>>> >>>> In C you can use *usleep()* and pass it the number of microseconds you >>>> want to pause. >>>> >>>> --Mark >>>> On Thursday, February 18, 2021 at 10:00:10 AM UTC-5 >>>> [email protected] wrote: >>>> >>>>> I've gone through the cookbook and it's very helpful. >>>>> >>>>> I'm still fuzzy on how to do what I need to do. >>>>> >>>>> My main code for controlling the valves, getting user input, etc. is >>>>> in C. >>>>> >>>>> I need to call a procedure in C that reads sensors. I will pass this >>>>> procedure the number of milliseconds it should read the sensors and then >>>>> return to the main program and turn the valves off. The number of >>>>> milliseconds can, and will likely, change depending on what we are >>>>> processing with these valves. I get that input at the start of the main >>>>> program. >>>>> >>>>> My thought is that in the procedure that reads the sensors, it will >>>>> grab a start time (doesn't have to be actual time) value from the PRU, >>>>> read >>>>> the sensors, and loop until the current time-start time equals the amount >>>>> of time it should read the sensors. Then it will return to the main >>>>> program. >>>>> >>>>> I just don't know how to read the PRU's clock to get the time values. >>>>> I don't think I saw an example in the cookbook for 'branching' out from >>>>> a >>>>> main program to use the PRUs for this type of processing. Just point me >>>>> in >>>>> the right direction, please. >>>>> >>>>> Walter >>>>> >>>>> >>>>> On Thursday, February 18, 2021 at 9:27:34 AM UTC-5 Walter Cromer wrote: >>>>> >>>>>> Mark , >>>>>> >>>>>> It is working with the updated OS. Thanks so much! >>>>>> >>>>>> Now I will explore how to get the simple timing that I need using the >>>>>> PRU. >>>>>> >>>>>> On Thursday, February 18, 2021 at 8:54:10 AM UTC-5 Walter Cromer >>>>>> wrote: >>>>>> >>>>>>> Mark, >>>>>>> >>>>>>> With the current OS there isn't a /dev/remoteproc even. >>>>>>> >>>>>>> I'm going to try the updated OS build this morning. >>>>>>> >>>>>>> Walter >>>>>>> >>>>>>> On Wednesday, February 17, 2021 at 5:34:37 PM UTC-5 Mark A. Yoder >>>>>>> wrote: >>>>>>> >>>>>>>> I fired up the Beagle at home it the PRU works out of the box. >>>>>>>> >>>>>>>> What do you get running >>>>>>>> *ls /dev/remoteproc* >>>>>>>> >>>>>>>> I get: >>>>>>>> *ls -ls /dev/remoteproc* >>>>>>>> total 0 >>>>>>>> 0 lrwxrwxrwx 1 root root 33 Feb 17 17:26 pruss-core0 -> >>>>>>>> /sys/class/remoteproc/remoteproc1 >>>>>>>> 0 lrwxrwxrwx 1 root root 33 Feb 17 17:26 pruss-core1 -> >>>>>>>> /sys/class/remoteproc/remoteproc2 >>>>>>>> >>>>>>>> If you are missing pruss-core0 and pruss-core1 you could try adding >>>>>>>> the links by hand and see what happens. >>>>>>>> >>>>>>>> *cd /dev/remoteproc* >>>>>>>> >>>>>>>> *sudo ln -s /sys/class/remoteproc/remoteproc1 pruss-core0* >>>>>>>> *sudo ln -s /sys/class/remoteproc/remoteproc2 pruss-core1* >>>>>>>> On Wednesday, February 17, 2021 at 3:56:21 PM UTC-5 >>>>>>>> [email protected] wrote: >>>>>>>> >>>>>>>>> I'll get this one onto an SD card and give it a try. If I can >>>>>>>>> just get this configured I think I can make quick work of this >>>>>>>>> problem! >>>>>>>>> >>>>>>>>> On Wednesday, February 17, 2021 at 3:47:04 PM UTC-5 Mark A. Yoder >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> Good point, it should work.... I'm running a newer test >>>>>>>>>> image[1], but I took my Beagle home so I can't do a quick check on >>>>>>>>>> it until >>>>>>>>>> later. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> --Mark >>>>>>>>>> [1] >>>>>>>>>> https://rcn-ee.com/rootfs/bb.org/testing/2021-02-15/buster-iot/bone-debian-10.8-iot-armhf-2021-02-15-4gb.img.xz >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On Wednesday, February 17, 2021 at 2:46:35 PM UTC-5 >>>>>>>>>> [email protected] wrote: >>>>>>>>>> >>>>>>>>>>> I asked because the ones on the page @ the link are older than >>>>>>>>>>> the one I have installed. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> On Wednesday, February 17, 2021 at 2:30:58 PM UTC-5 Mark A. >>>>>>>>>>> Yoder wrote: >>>>>>>>>>> >>>>>>>>>>>> On newer versions of the SD card image /var/lib/cloud9 is a git >>>>>>>>>>>> repo which you can do a git pull to update. Your version is too >>>>>>>>>>>> old. >>>>>>>>>>>> >>>>>>>>>>>> Follow the instructions at: >>>>>>>>>>>> https://markayoder.github.io/PRUCookbook/02start/start.html#_installing_the_latest_os_on_your_bone >>>>>>>>>>>> >>>>>>>>>>>> to download and install an updated version of the SD card image. >>>>>>>>>>>> >>>>>>>>>>>> --Mark >>>>>>>>>>>> >>>>>>>>>>>> On Wednesday, February 17, 2021 at 2:25:40 PM UTC-5 >>>>>>>>>>>> [email protected] wrote: >>>>>>>>>>>> >>>>>>>>>>>>> Mark, >>>>>>>>>>>>> >>>>>>>>>>>>> git pull on /var/lib/cloud9 fails with 'fatal: Not a git >>>>>>>>>>>>> repository (or any of the parent directories): .git >>>>>>>>>>>>> >>>>>>>>>>>>> I'm such a neophyte on git. What do I need to do? >>>>>>>>>>>>> >>>>>>>>>>>>> And, what do you mean by updating to a new version of the SD >>>>>>>>>>>>> card? The OS is booting from the SD card and the version.sh >>>>>>>>>>>>> information >>>>>>>>>>>>> posted earlier is based on that. >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> On Wednesday, February 17, 2021 at 2:02:55 PM UTC-5 Mark A. >>>>>>>>>>>>> Yoder wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>> I suggest updating to a new version of the SD card. It looks >>>>>>>>>>>>>> like the PRUs are getting started at boot time, but the path >>>>>>>>>>>>>> isn't setup >>>>>>>>>>>>>> right. I think we setup some links so the path* >>>>>>>>>>>>>> /dev/remoteproc/pruss-core0/state >>>>>>>>>>>>>> *points to the right place. >>>>>>>>>>>>>> >>>>>>>>>>>>>> You could also try: >>>>>>>>>>>>>> *cd */var/lib/cloud9 >>>>>>>>>>>>>> *git* pull >>>>>>>>>>>>>> to update cloud9 folders. >>>>>>>>>>>>>> >>>>>>>>>>>>>> --Mark >>>>>>>>>>>>>> >>>>>>>>>>>>>> On Wednesday, February 17, 2021 at 1:53:35 PM UTC-5 >>>>>>>>>>>>>> [email protected] wrote: >>>>>>>>>>>>>> >>>>>>>>>>>>>>> Mark, >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> I got the latest PRUCookbook downloaded and when trying to >>>>>>>>>>>>>>> make the hello.pru0.c program in 1.6, I got this error. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> *debian@beaglebone:/var/lib/cloud9/PRUCookbook/docs/02start/code$ >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> make TARGET=hello.pru0* >>>>>>>>>>>>>>> */var/lib/cloud9/common/Makefile:29: >>>>>>>>>>>>>>> MODEL=TI_AM335x_BeagleBone_Black,TARGET=hello.pru0* >>>>>>>>>>>>>>> *- Stopping PRU 0* >>>>>>>>>>>>>>> */bin/sh: 1: cannot create >>>>>>>>>>>>>>> /dev/remoteproc/pruss-core0/state: Directory nonexistent* >>>>>>>>>>>>>>> *Cannot stop 0* >>>>>>>>>>>>>>> *CC hello.pru0.c* >>>>>>>>>>>>>>> *"/var/lib/cloud9/common/prugpio.h", line 53: warning >>>>>>>>>>>>>>> #1181-D: #warning directive: "Found am335x"* >>>>>>>>>>>>>>> *LD /tmp/cloud9-examples/hello.pru0.o* >>>>>>>>>>>>>>> *- copying firmware file >>>>>>>>>>>>>>> /tmp/cloud9-examples/hello.pru0.out to >>>>>>>>>>>>>>> /lib/firmware/am335x-pru0-fw* >>>>>>>>>>>>>>> *cp: cannot create regular file >>>>>>>>>>>>>>> '/lib/firmware/am335x-pru0-fw': Permission denied* >>>>>>>>>>>>>>> */var/lib/cloud9/common/Makefile:180: recipe for target >>>>>>>>>>>>>>> 'install' failed* >>>>>>>>>>>>>>> *make: *** [install] Error 1* >>>>>>>>>>>>>>> *rm /tmp/cloud9-examples/hello.pru0.o* >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Initially, I did not have a folder called >>>>>>>>>>>>>>> /var/lib/cloud9/common. To remedy this I copied the contents >>>>>>>>>>>>>>> of >>>>>>>>>>>>>>> /var/lib/cloud9/PRUCookbook/docs/common to >>>>>>>>>>>>>>> /var/lib/cloud9/common. Maybe >>>>>>>>>>>>>>> this created a problem?Nevertheless, I found some other >>>>>>>>>>>>>>> discussions that >>>>>>>>>>>>>>> suggested updating the scripts and kernels from >>>>>>>>>>>>>>> beagleboard.org/upgrade which I did. I am now running... >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Linux beaglebone 4.14.108-ti-r137 #1stretch SMP PREEMPT Tue >>>>>>>>>>>>>>> Aug 25 01:48:39 UTC 2020 armv7l GNU/Linux >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> And the output of version.sh is >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> *debian@beaglebone:/$ sudo opt/scripts/tools/version.sh* >>>>>>>>>>>>>>> *[sudo] password for debian:* >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> *git:/opt/scripts/:[e4e4854ef8ff9ada5c85553376043ee7679167ca]* >>>>>>>>>>>>>>> *eeprom:[A335BNLT00C04417BBBK1847]* >>>>>>>>>>>>>>> *model:[TI_AM335x_BeagleBone_Black]* >>>>>>>>>>>>>>> *dogtag:[BeagleBoard.org Debian Image 2018-10-07]* >>>>>>>>>>>>>>> *bootloader:[microSD-(push-button)]:[/dev/mmcblk0]:[U-Boot >>>>>>>>>>>>>>> SPL 2018.09-00002-g0b54a51eee (Sep 10 2018 - 19:41:39 >>>>>>>>>>>>>>> -0500)]:[location: dd >>>>>>>>>>>>>>> MBR]* >>>>>>>>>>>>>>> *bootloader:[microSD-(push-button)]:[/dev/mmcblk0]:[U-Boot >>>>>>>>>>>>>>> 2018.09-00002-g0b54a51eee]:[location: dd MBR]* >>>>>>>>>>>>>>> *bootloader:[eMMC-(default)]:[/dev/mmcblk1]:[U-Boot SPL >>>>>>>>>>>>>>> 2018.03-00002-gac9cce7c6a (Apr 05 2018 - 13:07:46 >>>>>>>>>>>>>>> -0500)]:[location: dd >>>>>>>>>>>>>>> MBR]* >>>>>>>>>>>>>>> *bootloader:[eMMC-(default)]:[/dev/mmcblk1]:[U-Boot >>>>>>>>>>>>>>> 2018.03-00002-gac9cce7c6a]:[location: dd MBR]* >>>>>>>>>>>>>>> *UBOOT: Booted Device-Tree:[am335x-boneblack-uboot-univ.dts]* >>>>>>>>>>>>>>> *kernel:[4.14.108-ti-r137]* >>>>>>>>>>>>>>> *nodejs:[v6.14.4]* >>>>>>>>>>>>>>> */boot/uEnv.txt Settings:* >>>>>>>>>>>>>>> *uboot_overlay_options:[enable_uboot_overlays=1]* >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> *uboot_overlay_options:[uboot_overlay_addr0=/lib/firmware/BB-W1-P9.12-00A0.dtbo]* >>>>>>>>>>>>>>> *uboot_overlay_options:[disable_uboot_overlay_video=1]* >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> *uboot_overlay_options:[uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-14-TI-00A0.dtbo]* >>>>>>>>>>>>>>> *uboot_overlay_options:[enable_uboot_cape_universal=1]* >>>>>>>>>>>>>>> *pkg check: to individually upgrade run: [sudo apt install >>>>>>>>>>>>>>> --only-upgrade <pkg>]* >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> *pkg:[bb-cape-overlays]:[4.4.20180928.0-0rcnee0~stretch+20180928]* >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> *pkg:[bb-customizations]:[1.20180815-0rcnee0~stretch+20180815]* >>>>>>>>>>>>>>> *WARNING:pkg:[bb-usb-gadgets]:[NOT_INSTALLED]* >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> *pkg:[bb-wl18xx-firmware]:[1.20180517-0rcnee0~stretch+20180517]* >>>>>>>>>>>>>>> *pkg:[kmod]:[23-2rcnee1~stretch+20171005]* >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> *pkg:[librobotcontrol]:[1.0.3-git20181005.0-0rcnee0~stretch+20181005]* >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> *pkg:[firmware-ti-connectivity]:[20170823-1rcnee1~stretch+20180328]* >>>>>>>>>>>>>>> *groups:[debian : debian adm kmem dialout cdrom floppy audio >>>>>>>>>>>>>>> dip video plugdev users systemd-journal i2c bluetooth netdev >>>>>>>>>>>>>>> cloud9ide gpio >>>>>>>>>>>>>>> pwm eqep admin spi tisdk weston-launch xenomai]* >>>>>>>>>>>>>>> *cmdline:[console=ttyO0,115200n8 >>>>>>>>>>>>>>> bone_capemgr.uboot_capemgr_enabled=1 root=/dev/mmcblk0p1 ro >>>>>>>>>>>>>>> rootfstype=ext4 >>>>>>>>>>>>>>> rootwait coherent_pool=1M net.ifnames=0 quiet]* >>>>>>>>>>>>>>> *dmesg | grep remote* >>>>>>>>>>>>>>> *[ 1.147260] remoteproc remoteproc0: wkup_m3 is available* >>>>>>>>>>>>>>> *[ 1.231303] remoteproc remoteproc0: powering up wkup_m3* >>>>>>>>>>>>>>> *[ 1.231426] remoteproc remoteproc0: Booting fw image >>>>>>>>>>>>>>> am335x-pm-firmware.elf, size 217168* >>>>>>>>>>>>>>> *[ 1.233981] remoteproc remoteproc0: remote processor >>>>>>>>>>>>>>> wkup_m3 is now up* >>>>>>>>>>>>>>> *[ 108.634522] remoteproc remoteproc1: 4a334000.pru is >>>>>>>>>>>>>>> available* >>>>>>>>>>>>>>> *[ 108.656634] remoteproc remoteproc2: 4a338000.pru is >>>>>>>>>>>>>>> available* >>>>>>>>>>>>>>> *dmesg | grep pru* >>>>>>>>>>>>>>> *[ 108.019424] pruss 4a300000.pruss: creating PRU cores and >>>>>>>>>>>>>>> other child platform devices* >>>>>>>>>>>>>>> *[ 108.634522] remoteproc remoteproc1: 4a334000.pru is >>>>>>>>>>>>>>> available* >>>>>>>>>>>>>>> *[ 108.634642] pru-rproc 4a334000.pru: PRU rproc node >>>>>>>>>>>>>>> /ocp/pruss_soc_bus@4a326004/pruss@0/pru@34000 probed >>>>>>>>>>>>>>> successfully* >>>>>>>>>>>>>>> *[ 108.656634] remoteproc remoteproc2: 4a338000.pru is >>>>>>>>>>>>>>> available* >>>>>>>>>>>>>>> *[ 108.656808] pru-rproc 4a338000.pru: PRU rproc node >>>>>>>>>>>>>>> /ocp/pruss_soc_bus@4a326004/pruss@0/pru@38000 probed >>>>>>>>>>>>>>> successfully* >>>>>>>>>>>>>>> *dmesg | grep pinctrl-single* >>>>>>>>>>>>>>> *[ 0.783913] pinctrl-single 44e10800.pinmux: 142 pins at >>>>>>>>>>>>>>> pa f9e10800 size 568* >>>>>>>>>>>>>>> *dmesg | grep gpio-of-helper* >>>>>>>>>>>>>>> *[ 0.796624] gpio-of-helper ocp:cape-universal: ready* >>>>>>>>>>>>>>> *lsusb* >>>>>>>>>>>>>>> *Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root >>>>>>>>>>>>>>> hub* >>>>>>>>>>>>>>> *END* >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Any ideas? >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> On Wednesday, February 17, 2021 at 10:10:53 AM UTC-5 Mark A. >>>>>>>>>>>>>>> Yoder wrote: >>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> The PRUs can give you 10's of ns timing, which is more than >>>>>>>>>>>>>>>> good enough for milliseconds, but might be over kill. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> I'd think using C on the ARM processor should be fast >>>>>>>>>>>>>>>> enough. I'd use gpiod[1]. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> If you really want the ns timing of the PRUs, check out the >>>>>>>>>>>>>>>> PRU Cookbook[2] >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> --Mark >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> [1] https://github.com/starnight/libgpiod-example >>>>>>>>>>>>>>>> [2] https://github.com/MarkAYoder/PRUCookbook >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> On Tuesday, February 16, 2021 at 10:51:11 AM UTC-5 >>>>>>>>>>>>>>>> [email protected] wrote: >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Depending on how precise you need to be, I would go for >>>>>>>>>>>>>>>>> the PRU-ICSS. They can control the GPIOs pretty easily. >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Le mardi 16 février 2021 à 10:03:47 UTC-5, >>>>>>>>>>>>>>>>> [email protected] a écrit : >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> I have a BBB Wireless running Linux beaglebone >>>>>>>>>>>>>>>>>> 4.14.108-ti-r106 #1 SMP PREEMPT Fri May 24 22:12:34 UTC 2019 >>>>>>>>>>>>>>>>>> armv7l >>>>>>>>>>>>>>>>>> GNU/Linux >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> I am writing in C. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> I turn a valve on and then need to read some sensors for >>>>>>>>>>>>>>>>>> N milliseconds and then turn the valve off. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> What's the best way to read milliseconds on the BBBw? I >>>>>>>>>>>>>>>>>> don't have a RTC on this particular unit but could add one >>>>>>>>>>>>>>>>>> using I2C. I >>>>>>>>>>>>>>>>>> have an Adafruit 4282 with a DS3231 RTC on it on another >>>>>>>>>>>>>>>>>> BBBw that I could >>>>>>>>>>>>>>>>>> use temporarily to prove it works. What other options are >>>>>>>>>>>>>>>>>> available? >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> -- 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/15c68b45-9390-49b7-aa6f-7b70b0e407a1n%40googlegroups.com.
