Jetson Nano Developer Kit 40-Pin Expansion Header Configuration - Enabling SPI, modifying GPIOs, etc...

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

Hi,

Has anybody got any success following Jetson Nano Developer Kit 40-Pin Expansion Header Configuration Application Note and enabling SPI, modifying GPIOs (pull-up/pull-down), etc?

I went through the application note but after

sudo ./flash.sh jetson-nano-qspi-sd mmcblk0p1

Nano won’t boot it got stuck on BIOS/Nvidia Screen

I tried to use

./flash.sh -r -k DTB jetson-nano-qspi-sd mmcblk0p1

and

sudo ./flash.sh --no-sytemimg -k DTB jetson-nano-qspi-sd mmcblk0p1

But these haven’t modified device tree as there was no /dev/spidev*

I think there is a missing step in Jetson Nano Developer Kit 40-Pin Expansion Header Configuration Application Note and I would be great if somebody could share their experience (it would be good if Nvidia would update this App Note)

Went through over topics to but I have not found solution that would work for me.

Also if anybody knows a better way of modifying the SoC pinmux, maybe on the fly through device tree files etc., please share them as well.

2

Please follow below link to enable SPI.

3

Thanks for that it is quite easy way of enabling SPI.

But what if I want to enable/disable I2C or modify internal pull-up/down resistors (I would like to be able to modify these things as well). Does changing pinmux through the spreadsheet still fails as described by in topic 1063105? https://devtalk.nvidia.com/default/topic/1063105/jetson-nano/can-t-get-jetson-nano-to-boot-with-custom-pinmux-configuration-per-nvidia-instructions/

If I want to enable/change internal pull-up/down resistors, do you have to only make changes in pinmux-config-p3450-porg.h or do you have to modify any .dtsi files as well. Do you have any datasheets/app notes which describes process of manually modifying these files in details?

GPIO 7, 31 are normally set to be pulled up, would removing internal res. on those pins or modifying them can cause any other functionality of the Nano to misbehave?
GPIO 12, 36 cannot be controlled from Jetson.GPIO python lib, got stuck on 1.5V, is there any reason behind it?

Just on the side note is the process of modifying GPIOs, enabling SPI, etc. similar for TX2 as for Nano?

4

I think you may need to modify both of them due to the dtsi may override it.