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/0450a2b4-4b7a-4d8b-98b4-9261c81d6863n%40googlegroups.com.
