GPIOs exported by default + missing HDMI and eMMC capes

Hello all.
I am a complete newbie to Beaglebone.
I have only worked with AVR before, but I once bought this Beaglebone Black and now I need to write a simple logger (probably it’ll be in bash) and I thought it might be much easier since I already have ethernet, lots of memory to store the logs and more than enough GPIOs.
The first thing I did was to download the latest image in the beaglebone webpage flashed the emmc.
Having read a little on the internet I found how to export a GPIO pin and work with it from the filesystem. The beaglebone webpage says two digital capes come by default (HDMI and eMMC) and the pinout specifies which pins are free to be used.
GPIO60 is one of them. But when going to /sys/class/gpio I see many pins already exported (not by me):

`

root@beaglebone:/sys/class/gpio# ls

export gpio14 gpio26 gpio4 gpio48 gpio60 gpio68 gpiochip64

gpio112 gpio15 gpio27 gpio44 gpio49 gpio61 gpio69 gpiochip96

gpio114 gpio2 gpio3 gpio45 gpio5 gpio65 gpio7 unexport

gpio115 gpio22 gpio30 gpio46 gpio50 gpio66 gpiochip0

gpio116 gpio23 gpio31 gpio47 gpio51 gpio67 gpiochip32

`

These pins are not used (at least by what the diagrams specify) by any digital cape, and they show up no matter how many times I restart the board.
And what is even more odd (to me at least), when I go to /sys/devices/platform/bone_capemgr and cat the slots file, I see:

`

root@beaglebone:/sys/devices/platform/bone_capemgr# cat slots

  • 0: PF---- -1

1: PF---- -1

2: PF---- -1

3: PF---- -1

4: P-O-L- 0 Override Board Name,00A0,Override Manuf,cape-universaln

`

I don’t see the HDMI or eMMC capes.
I could have used some other pin but I really would like to understand this.
Does anyone know what is going on here? I haven’t done anything on it after flashing the eMMC with the new software other than installing msmtp, which I was going to use for my project. There’s nothing connected to it other than the ethernet cable (usb network doesn’t seem to work on OSX El Capitan).
Thanks for taking the time to read this long (and probably stupid) post.

Hello all.
I am a complete newbie to Beaglebone.
I have only worked with AVR before, but I once bought this Beaglebone Black and now I need to write a simple logger (probably it’ll be in bash) and I thought it might be much easier since I already have ethernet, lots of memory to store the logs and more than enough GPIOs.
The first thing I did was to download the latest image in the beaglebone webpage flashed the emmc.
Having read a little on the internet I found how to export a GPIO pin and work with it from the filesystem. The beaglebone webpage says two digital capes come by default (HDMI and eMMC) and the pinout specifies which pins are free to be used.
GPIO60 is one of them. But when going to /sys/class/gpio I see many pins already exported (not by me):

root@beaglebone:/sys/class/gpio# ls

export gpio14 gpio26 gpio4 gpio48 gpio60 gpio68 gpiochip64

gpio112 gpio15 gpio27 gpio44 gpio49 gpio61 gpio69 gpiochip96

gpio114 gpio2 gpio3 gpio45 gpio5 gpio65 gpio7 unexport

gpio115 gpio22 gpio30 gpio46 gpio50 gpio66 gpiochip0

gpio116 gpio23 gpio31 gpio47 gpio51 gpio67 gpiochip32

These pins are not used (at least by what the diagrams specify) by any digital cape, and they show up no matter how many times I restart the board.
And what is even more odd (to me at least), when I go to /sys/devices/platform/bone_capemgr and cat the slots file, I see:

root@beaglebone:/sys/devices/platform/bone_capemgr# cat slots

  • 0: PF---- -1

1: PF---- -1

2: PF---- -1

3: PF---- -1

4: P-O-L- 0 Override Board Name,00A0,Override Manuf,cape-universaln

I don’t see the HDMI or eMMC capes.
I could have used some other pin but I really would like to understand this.

With 4.1 HDMI and emmc is enabled and built in by default…

Read

https://github.com/beagleboard/bb.org-overlays/blob/master/readme.md

Under compatibility section how to disable thru /boot/uEnv.txt

Does anyone know what is going on here? I haven’t done anything on it after flashing the eMMC with the new software other than installing msmtp, which I was going to use for my project. There’s nothing connected to it other than the ethernet cable (usb network doesn’t seem to work on OSX El Capitan).
Thanks for taking the time to read this long (and probably stupid) post.

Known issue, Apple broke it…

https://github.com/jwise/HoRNDIS/issues/42

Regards,

https://github.com/cdsteinkuehler/beaglebone-universal-io

The above link should help a lot.

Regards,
Greg

Oh I see! This plus what Robert said about HDMI and eMMC does explain a lot.

Thanks!

Regards,

Augusto