Repurpose GPIO(controlled by SPE) to UART on 40-pin header

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Orin
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1

Hi,
I am using AGX Orin devkit.
I want to repurpose pin 16(GPIO08) and pin 32(GPIO09) on 40 pin header from GPIO to UART
I tried 2 method

  1. manually config by Jetson-io.py, but those two pin has no option to be configured as UART
  2. using pinmux spreadsheet: Orin_Jetson_Series_Pinmux_Config_Template_2.0.
    but both pin doesn’t have option to be configured as UART
    would you advise that does it means from hardware perspective there is no way to repurpose the 2 GPIO pin to UART?
    *I did found UART driver in spe-freertos-bsp, and wonder if it’s possible to modify that driver to drive those 2 GPIO pin as UART?

Thanks!

2

Hi,

If you are designing a custom base board, then it means some adaptation configurations are needed.
Otherwise, your board may not work fine.

For Orin AGX series, you could refer to below document

(please be aware that above link is for rel-36.3/jetpack6.0)

This document includes below configuration

  1. pinmux change & GPIO configuration
  2. EEPROM change as most custom boards do not have an EEPROM on it.
  3. Kernel porting
  4. PCIe configuration
  5. USB configuration
  6. MGBE configuration
  7. RGMII configuration

Thanks!

3

Hi,

  1. I am not using custom board, I am using AGX Orin devkit
  2. as document mentioned I should refer to pinmux-spreadsheet and I did check it out, there is no such option, does it mean from hardware perspective it’s not feasible?
6

Hi tsuchieh.chen,

What’s the Jetpack version in use?

They are both expected since these 2 pins can not be used as UART.

I’ve checked the NVIDIA Jetson AGX Orin Developer Kit Carrier Board document(SP-10900-001_v1.2).
It seems these 2 pins can not be used as UART.
If you have the requirement for UART, please use PIN8/PIN10 of 40-pins header instead.
image

7

Hi Kevin,
1.What’s the Jetpack version in use? it’s r35.3.1
2.I understand it’s not default configurable to UART, but wonder if it’s possible I can modify existing driver to configure it to UART. because I need UART controlled by SPE instead of main CPU(UART suggested by you controlled by main CPU). I wonder if it’s hardware limit that it’s impossible to configure pin 16 & 32 as UART or it’s just pinmux firmware/software setting limit which might be feasible to modify it.

Thanks!

8

pinmux spreadsheet allows you to configure how do you want to use the pins.
All available functions are listed in pinmux spreadsheet, they are determined from hardware.

For UART, please refer to Jetson AGX Orin Series Modules Design Guide.
Table 15-1. Orin Module UART Pin Description in Chapter 15. UART shows the available UART interfaces for AGX Orin.

1 Like
10
  1. would you share the file link you are referring to? I can’t find what you mentioned.
  2. per your comment about pinmux spreadsheet, does it means the 2 GPIO pins(pin 16 & 32) have no way to reconfigured as UART?
11

Log in | NVIDIA Developer
You can find it from Jetson Download Center

Correct.

Could you elaborate on your use case?
Are you trying to to SPE to control UART? What’s your connection?

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  1. I can only find these without “Jetson AGX Orin Series Modules Design Guide”
    image
    image1455×280 44.2 KB
  2. camera, I want SPE to get some pictures
13

There is no update from you for a period, assuming this is not an issue anymore.
Hence, we are closing this topic. If need further support, please open a new one.
Thanks ~0409

Have you logged-in to your account?
Please check the following link with search keyword included.
Jetson Download Center | NVIDIA Developer

Does your camera use UART as communication interface?
Why you don’t want to use existed UART from CPU?