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GPIO PPS
#1
The WIKI gives an example of using Pin 22 for GPS PPS  https://tinkerboarding.co.uk/wiki/index....tle=NEO-6M I would like to change to Pin 18 for PPS. The overlay is /debian_kernel/arch/arm/boot/dts/overlays/pps-gpio-overlay.dts.  I don't know what to change or how to build.  I believe I just need to build the overlay not the entire kernel with the device-tree compiler.  I'm using a GPS HAT that has PPS on Pin 18 (RPi GPIO24/Pin 18)).  Thank you for any advice. 

dk23
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#2
https://github.com/TinkerBoard/debian_kernel/issues/30
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#3
Summary of what I did to change PPS to pin 18 from pin 22:

I'm using a GPS RPi hat that has PPS on pin 18, the pps-gpio.dtbo for TB has PPS on pin 22.

on RPi
dtoverlay=pps-gpio,gpiopin=24
maps to pin 18 of RPi
need PPS on pin 18 of TB

Get tools 

Code:
[/font][/size]

[size=medium][font=Consolas, monospace]$ sudo apt-get install pps-tools device-tree-compiler[/font][/size]

$ cp /boot/overlays/pps-gpio.dtbo ~/src/pps-gpio/

$ cd ~/src/pps-gpio/

$ dtc pps-gpio.dtbo > pps-gpio.dts # might see warnings

How to MAP TB pin 18 to GPIO:

see: https://github.com/TinkerBoard/debian_kernel/issues/30

pin 18 → GP5B3 = 11 (0xB)

$ vi pps-gpio.dts

replace 0x13 with 0xB (2 locations)

$ dtc pps-gpio.dts > pps-gpio18.dtbo # might see warnings

$ sudo cp pps-gpio18.dtbo /boot/overlays

$ sudo vi /boot/hw_intf.conf

intf:dtoverlay=pps-gpio18

$ sudo reboot

# ppstest /dev/pps0

source 0 - assert 1584653968.177904025, sequence: 143 - clear 0.000000000, sequence: 0

...
[size=medium][font=Consolas, monospace]


I was unable to compile 
/debian_kernel/arch/arm/boot/dts/overlays/pps-gpio-overlay.dts

so I decompiled pps-gpio.dtbo 

dk23
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