Hello,
I am semi new at using the BBB, and am finding a lot of conflicting information on the web regarding gpio pins and their use. My goal here is to input a 1pps signal into the BBB for time sync using ntp. I have found several tutorials online, but they all talk about using a custom overlay. I am not sure if this is old information and am I supposed to use the config-pin utility?
Ultimately, I am trying to read in NMEA (gps) time info along with the 1pps signal. I am also trying to use two ADC’s as inputs and use 4 GPIO pins as outputs. Does this require a custom DTS overlay or do I use the config-pin utility?
Thanks for the clairificaiton
Use an overlay, or patch your main *.dtb for pps device tree node..
here's one example i did with the PocketBeagle + GNSS 5 click
https://www.mikroe.com/gnss-5-click
https://github.com/beagleboard/bb.org-overlays/blob/master/src/arm/PB-UART4-GNSS-5-CLICK.dts
Regards,
With the PocketBeagle, "cape-universal" is built-into the base *.dtb..
For the BeagleBone Black, this will be the default for v4.16.x+
So for the BeagleBone Black, with a less then v4.16.x based kernel,
you don't need to 'disable' the taken pins, just define and use them.
An overlay, doesn't have to be "one" node, you can combine all your
modifications into one overlay aka pps and adc pins..
Regards,
Sounds good. Ill do some research on creating my own overlay.
Lastly, is the config-pin utility outdated and not needed anymore?
Seems that I am finding lots of tutorials that either utilize that
application or the device tree overlays. Just want to make sure I am
focusing on the correct method..
config-pin is more for the prototyping phase.. aka, let's try this
wired here and test it..
Where-as the overlay is more... I've built an adapter card, and just
want it configured on bootup.
Regards,