Dear Jon Thank you for your reply, and I'm sorry I haven't been able to reply for a long time. In the end, I couldn't take the time to find a way to quickly turn off the LEDs, so I decided to postpone this story. I'm sorry I couldn't give back the information to everyone because of this result.
2021年1月8日金曜日 14:28:07 UTC+9 [email protected]: > I think what you are looking for is a bit lower level than the Kernel > since you are looking to control the LEDs at power on. > You may want to have a look at the Boot Sequence of the BBB and see if > there is a place you can set this like you want. I'm not sure if you can do > this from U-Boot though. > https://elinux.org/EBC_Exercise_21a_Boot_Sequence > > The other option is to set a cron job to turn off the LED at reboot > considering you are already turning it on from the device tree. You may > have to play with the timing to get it the way you want. However depending > on what happens at boot, the timing could be off. > Ex: > > https://billwaa.wordpress.com/2014/10/03/beaglebone-black-launch-python-script-at-boot-like-arduino-sketch/ > > Jon > > > On Thu, Jan 7, 2021 at 9:15 PM ha ppay <[email protected]> wrote: > >> Dear All >> Does anyone have any ideas? >> If you have any ideas on how to add LEDs, please let me know. >> Regards, >> >> 2021年1月7日木曜日 10:37:31 UTC+9 ha ppay: >> >>> >>> >>> Hi >>> Thank you for your reply, and the book's title! >>> I checked table of contents of the book. >>> Maybe, The Chapter 6 is that? >>> I have experiences to control GPIO by python, and configure the device >>> tree's defualt setting, write to value&direction file. >>> I changed the GPIO Pin setting of device tree file to out&High for the >>> LED turn on when bbb is powered on. >>> But I can't find the method to turn off the LED in a few seconds. I >>> tried to write python script to turn off the LED, and Systemd run the >>> service script( using the After setting is "generic-board-startup.service >>> ). >>> but the timing is over 1minutes from the bbbw is powered on! >>> I'm looking for the information of "as soon as bbb is powered on". >>> I'm not familiar with embedded Linux. In particular, I have little idea >>> about the behavior of driver-related programs. I'm wondering if the >>> driver's program should do this. >>> >>> 2021年1月6日水曜日 22:39:14 UTC+9 [email protected]: >>> >>>> Hi! >>>> Yes! I'm pretty sure that the Derek Molloy's "Exploring BeagleBone: >>>> Tools and Techniques for Building with Embedded Linux" book has the >>>> examples that you are looking for in various programming languages. >>>> >>>> El mié., 6 de ene. de 2021 10:16, BBBW User A <[email protected]> >>>> escribió: >>>> >>>>> >>>>> Hi everyone. >>>>> >>>>> I'm BBBW user. >>>>> Could you tell me below question. >>>>> >>>>> Is there a wai to turn on the GPIO Controlled LED for a few seconds as >>>>> soon as the bbbw is powered on, like user leds? >>>>> and How to do it? >>>>> >>>>> Regards, >>>>> >>>>> -- >>>>> 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/364a2d6d-897f-4c72-99e0-4008f5504c77o%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/beagleboard/364a2d6d-897f-4c72-99e0-4008f5504c77o%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- >> 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/0a6c3263-ab7f-4b92-80a6-ad2f4cd5ff1dn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/beagleboard/0a6c3263-ab7f-4b92-80a6-ad2f4cd5ff1dn%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- 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/be4efe78-d146-4e79-8994-e6c9845d1b69n%40googlegroups.com.
