Commit adaad5af authored by neilneil2000's avatar neilneil2000 Committed by Phil Elwell
Browse files

GPIO and gpio-poweroff clarifications 

Notes added:
1) All GPIO references use the hardware numbering scheme
2) Enabling gpio-poweroff prevents the ability to boot the pi by driving GPIO3 low
parent 0ec723f8

arch/arm/boot/dts/overlays/README

+5 −1
Original line number Diff line number Diff line
@@ -33,6 +33,9 @@ needed. 
Configuring additional, optional hardware is done using Device Tree overlays

(see below).



GPIO numbering uses the hardware pin numbering scheme (aka BCM scheme) and 

not the physical pin numbers.



raspi-config

============
@@ -496,7 +499,8 @@ Params: gpio_pin Input pin number. Default is 18. 




Name:   gpio-poweroff

Info:   Drives a GPIO high or low on poweroff (including halt)

Info:   Drives a GPIO high or low on poweroff (including halt). Enabling this

        overlay will prevent the ability to boot by driving GPIO3 low.

Load:   dtoverlay=gpio-poweroff,<param>=<val>

Params: gpiopin                 GPIO for signalling (default 26)