Control the user LED using the user Boot button on the BeagleBone Black

General Discussion
1

Hi Support

Is it possible to use the user boot button to turn off/on the user LEDs?
Which pin on the processor is the user boot button connected to?
I want to use the boot button for control, since then I do not have to
connect any wires on the board.

Kind regards
Aravindh

2

the SD boot button is connected to the LCD_DATA2 pin. This is also GPIO0_22 so yes you can access this assuming you configure the pin as GPIO and are not using an LCD.

3

Thanks for the info. But according to the latest BeagleBone Black schematics in Github, LCD_DATA2 pin is the same as GPIO2_8 (pin 72).

image
image1427×105 52.8 KB

4

Yes you are correct. I did a search for LCD_DATA2 on the schematic, but failed to noticed it matched on LCD_DATA23. So you need to read GPIO2.8 to get the button status.

So you would need to export gpio 72 and set the direction to in.
edit can’t count today, 72 not 74

5

Thanks for the support. I configured pin 72 as GPIO In and also attached an edge rising flank interrupt to it. It works good.