Hi, I am a newbie to the linux environment and BBB, your information is very helpful.
I've have tested both BB-I2C1-RTC-DS3231.dtbo and BB-I2C2-RTC-DS3231.dtbo in the new image 4.19.94-ti-r42, they mount rtc1 in /dev but system time is not updated with rtc1. Please let me know if any other procedure is required and also procedure to update external rtc1 time when the internet is connected. One thing i have observed, with BB-I2C1-RTC-DS3231.dtbo the timedatectl command displayed "RTC time: n/a" not system time as in normal condition. Please clarify the following points 1. How do you say the rtc chip is in i2c bus one. Using i2cdetect command "i2cdetect -r 2" , 0x68 external device showed in i2c bus two. 2. I understand overlay is an out of box approach. In 4.4.30-ti-r64, system time updated with "echo ds3231 0x68 > /sys/class/i2c-adapter/i2c-1/new_device; hwclock -r -f /dev/rtc1" in /etc/rc.local. Is there any problem if I use this approach in older images? Regards, NK On Tue, Aug 25, 2020 at 7:45 PM Tarmo <[email protected]> wrote: > On Monday, 24 August 2020 00:12:39 UTC+3, Alexander Zangerl wrote: >> >> On Thu, 20 Aug 2020 00:40:38 -0700, Niresh Kumar writes: >> >1). I have placed the following lines in the /etc/rc.local, and system >> >time gets updated with external RTC DS3231 automatically at every reboot >> > >> >*echo ds3231 0x68 > /sys/class/i2c-adapter/i2c-1/new_device* >> ... >> > >> >2) I have put the line *dtb_overlay = >> >/lib/firmware/BB-I2C2-RTC-DS3231.dtbo * in /boot/uEnv.txt but it does >> not >> >> >> the overlay you're using won't work because your rtc chip is >> on i2c bus one: as its name (...I2C2...) indicates it's for a >> clock chip being on i2c bus two. >> >> use dtc to decompile that overlay, edit for i2c1 and dtc it back into >> binary form. >> >> > Good catch, although it's probably not necessary to decompile binary trees > as the source is available here together with a nice makefile to build a > single overlay: > https://github.com/beagleboard/bb.org-overlays > > Without having tested it, I might imagine a process similar to this one: > > $ git clone https://github.com/beagleboard/bb.org-overlays.git > $ cd bb.org-overlays > $ cp src/arm/BB-I2C2-RTC-DS3231.dts src/arm/BB-I2C1-RTC-DS3231.dts > $ vim src/arm/BB-I2C1-RTC-DS3231.dts > ... update I2C bus number ... > $ make src/arm/BB-I2C1-RTC-DS3231.dtbo > $ cp src/arm/BB-I2C1-RTC-DS3231.dtbo /lib/firmware > > -- > Kind regards, > Tarmo > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to a topic in the > Google Groups "BeagleBoard" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/beagleboard/m4hZYsA-d8M/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/ffd21cc3-37ea-4526-80da-b4e1ae428d66o%40googlegroups.com > <https://groups.google.com/d/msgid/beagleboard/ffd21cc3-37ea-4526-80da-b4e1ae428d66o%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/CAF7-PaQZivPdP39Ei05yUWBi9BUCCNY5PPaD6p7JWoMbUskB6Q%40mail.gmail.com.
