PPS GPIO with Buildroot image on Raspberry Pi 3
I'm a beginner with Buildroot trying to build a Linux image for the Raspberry Pi 3 in which I have access to pulse-per-second (PPS) inputs on one of the GPIO pins.
First off, I have tried this with the standard Raspbian distribution and got it to work with the following changes:
- Add
dtoverlay=pps-gpio,gpiopin=20to/boot/config.txt. - Add
pps-gpioto/etc/modules.
I then get an entry /dev/pps0 and when connecting a wire with PPS signal to physical pin 38 on the RPi3 and running pps-test /dev/pps0 I get the expected one signal per second.
So far so good.
Now I would like to recreate this with my own image built with Buildroot. I'm using the default configs/raspberrypi3_64_defconfig configuration, but with the following changes in make nconfig:
- Using kernel branch
rpi-4.14.y-rtfromgithub.com/raspberrypi/linux
systemdas init system/dev management using udev (from systemd)
Target packages->Hardware handling->pps-toolsactivated
(I think that is all the changes I made, but I might have forgotten something..)
In the sdcard.img which I get as output I see the file pps-gpio.dtbo in the boot partition. I add the line dtoverlay=pps-gpio,gpiopin=20 to the file config.txt. I also add the line pps-gpio to a file named pps.conf which I put in /etc/modules-load.d on the file system.
When I boot the system I get no entry /dev/ppsX but when I run lsmod I get (among others):
pps_gpio 16384 0
pps_core 20480 1 pps_gpio
Does this mean the dtoverlay has been correctly loaded? What can I try in order to get an entry in /dev/ppsX?
Thanks!
linux udev buildroot device-tree
asked Mar 4 at 16:05
Isak T.Isak T.
61
add a comment |
I'm a beginner with Buildroot trying to build a Linux image for the Raspberry Pi 3 in which I have access to pulse-per-second (PPS) inputs on one of the GPIO pins.
First off, I have tried this with the standard Raspbian distribution and got it to work with the following changes:
- Add
dtoverlay=pps-gpio,gpiopin=20to/boot/config.txt. - Add
pps-gpioto/etc/modules.
I then get an entry /dev/pps0 and when connecting a wire with PPS signal to physical pin 38 on the RPi3 and running pps-test /dev/pps0 I get the expected one signal per second.
So far so good.
Now I would like to recreate this with my own image built with Buildroot. I'm using the default configs/raspberrypi3_64_defconfig configuration, but with the following changes in make nconfig:
- Using kernel branch
rpi-4.14.y-rtfromgithub.com/raspberrypi/linux
systemdas init system/dev management using udev (from systemd)
Target packages->Hardware handling->pps-toolsactivated
(I think that is all the changes I made, but I might have forgotten something..)
In the sdcard.img which I get as output I see the file pps-gpio.dtbo in the boot partition. I add the line dtoverlay=pps-gpio,gpiopin=20 to the file config.txt. I also add the line pps-gpio to a file named pps.conf which I put in /etc/modules-load.d on the file system.
When I boot the system I get no entry /dev/ppsX but when I run lsmod I get (among others):
pps_gpio 16384 0
pps_core 20480 1 pps_gpio
Does this mean the dtoverlay has been correctly loaded? What can I try in order to get an entry in /dev/ppsX?
Thanks!
linux udev buildroot device-tree
asked Mar 4 at 16:05
Isak T.Isak T.
61
add a comment |
I'm a beginner with Buildroot trying to build a Linux image for the Raspberry Pi 3 in which I have access to pulse-per-second (PPS) inputs on one of the GPIO pins.
First off, I have tried this with the standard Raspbian distribution and got it to work with the following changes:
- Add
dtoverlay=pps-gpio,gpiopin=20to/boot/config.txt. - Add
pps-gpioto/etc/modules.
I then get an entry /dev/pps0 and when connecting a wire with PPS signal to physical pin 38 on the RPi3 and running pps-test /dev/pps0 I get the expected one signal per second.
So far so good.
Now I would like to recreate this with my own image built with Buildroot. I'm using the default configs/raspberrypi3_64_defconfig configuration, but with the following changes in make nconfig:
- Using kernel branch
rpi-4.14.y-rtfromgithub.com/raspberrypi/linux
systemdas init system/dev management using udev (from systemd)
Target packages->Hardware handling->pps-toolsactivated
(I think that is all the changes I made, but I might have forgotten something..)
In the sdcard.img which I get as output I see the file pps-gpio.dtbo in the boot partition. I add the line dtoverlay=pps-gpio,gpiopin=20 to the file config.txt. I also add the line pps-gpio to a file named pps.conf which I put in /etc/modules-load.d on the file system.
When I boot the system I get no entry /dev/ppsX but when I run lsmod I get (among others):
pps_gpio 16384 0
pps_core 20480 1 pps_gpio
Does this mean the dtoverlay has been correctly loaded? What can I try in order to get an entry in /dev/ppsX?
Thanks!
linux udev buildroot device-tree
asked Mar 4 at 16:05
Isak T.Isak T.
61
I'm a beginner with Buildroot trying to build a Linux image for the Raspberry Pi 3 in which I have access to pulse-per-second (PPS) inputs on one of the GPIO pins.
First off, I have tried this with the standard Raspbian distribution and got it to work with the following changes:
- Add
dtoverlay=pps-gpio,gpiopin=20to/boot/config.txt. - Add
pps-gpioto/etc/modules.
I then get an entry /dev/pps0 and when connecting a wire with PPS signal to physical pin 38 on the RPi3 and running pps-test /dev/pps0 I get the expected one signal per second.
So far so good.
Now I would like to recreate this with my own image built with Buildroot. I'm using the default configs/raspberrypi3_64_defconfig configuration, but with the following changes in make nconfig:
- Using kernel branch
rpi-4.14.y-rtfromgithub.com/raspberrypi/linux
systemdas init system/dev management using udev (from systemd)
Target packages->Hardware handling->pps-toolsactivated
(I think that is all the changes I made, but I might have forgotten something..)
In the sdcard.img which I get as output I see the file pps-gpio.dtbo in the boot partition. I add the line dtoverlay=pps-gpio,gpiopin=20 to the file config.txt. I also add the line pps-gpio to a file named pps.conf which I put in /etc/modules-load.d on the file system.
When I boot the system I get no entry /dev/ppsX but when I run lsmod I get (among others):
pps_gpio 16384 0
pps_core 20480 1 pps_gpio
Does this mean the dtoverlay has been correctly loaded? What can I try in order to get an entry in /dev/ppsX?
Thanks!
linux udev buildroot device-tree
linux udev buildroot device-tree
asked Mar 4 at 16:05
Isak T.Isak T.
61
asked Mar 4 at 16:05
Isak T.Isak T.
61
asked Mar 4 at 16:05
Isak T.Isak T.
61
asked Mar 4 at 16:05
Isak T.Isak T.
61
asked Mar 4 at 16:05
Isak T.Isak T.
61
61
add a comment |
add a comment |
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