Using GPIO pins from Camera Expansion connector pins on AGX Orin

Autonomous Machines Jetson & Embedded Systems Jetson AGX Orin
1

Hello,

I want to use GPIO pins in the camera expansion connector pins.
There are 4 pins that I want to use : GPIO10(#85), GPIO6(#97), GPIO13(#96), GPIO7(#98)
I could see that they are for Camera FRSYNC, so I want to make “square wave”(PWM) to frame sync generation.
I tried to configure from /opt/nvidia/jetson-io/jetson-io.py but there was only #96 for dmic2 which I don’t know well.

How can I use these pins for PWM generator?
And I want to know if I can use it with python Jetson.GPIO module.

Thank you.

3

Hi,

Please enable these pins as GPIO by changing pinmux settings.
https://docs.nvidia.com/jetson/archives/r36.2/DeveloperGuide/HR/JetsonModuleAdaptationAndBringUp/JetsonAgxOrinSeries.html#pinmux-changes

4

Hello DaveYYY,

Thanks for your answer.
Since I don’t know well about kernel things, I have more questions.

I am using L4T 35.1 and python3 Jetson.GPIO to control GPIO.
Do I have to update gpio_pin_data.py?
If so, can you guide me how?

5

NO, I mean please learn more about pinmux.
You cannot use these pins now because they are not configured as GPIO, and you have to change it by specifying them in the pinmux spreadsheet.
It has nothing to do with Jetson.GPIO.

6

Oh, I understood.
I’ll try and ask you again. Thank you.

7

I think this way makes only the pins to normal GPIO, not PWM-able pin.
Since I want to use this as Frame synchronization,
is there any way to output desirable frame sync signal from these pins?
The original usage of CAM_FRSYNC1 (CIM PIN#85) is TSC_EDGE_OUT0 and I found out that TSC_EDGE_OUT signals are used as FSYNC signals supplied to sensors through the deserializer and the serializer.
for ex. I want to make 30fps frame sync signal.

9

hello hscho0316,

may I know what’s real use-case of your frame synchronization?

according to JAO: TSC with PPS or PTP - #12 by JerryChang.
we’ve not yet support using TSC_EDGE_OUT feature for camera frame sync on L4T.
however, there’s software approach, suggest to check Topic 1070823 for reference.

11

Hello JerryChang,
Thank you for your answer.
My use-case is to connect 4cameras, via custom made board,
and the cameras are slave mode, which takes the image when the edge signal comes. So I want to make this signal and synchronize all.
So I designed a board to pull the signals of CAM_FRSYNCs, and wanted to enable it.
It is okay with at least one signal, but I want to enable and control them.

13

Or I can try to use pin #91(EXTPERIPH1_CLK/GPIO PP0), if I can use.
Is there any chance to control?
J54 MCLK02 EXTPERIPH1_CLK GP52_CLK1 50k pd EXTPERIPH1_CLK Output Drive 0 Disable Camera Master Clock 1 MCLK02_MCLK

14

hello hscho0316,

let me double confirm.
are you asking the approach to create external trigger for camera FSYNC.

15

Hello JerryChang,

yes, I want to make external trigger signal to frame sync by using a pin of CSI Connector.

16

hello hscho0316,

assume you already have hardware connection to the FSYNC pin.

you’ll need to configure the pin as PWM, for example, you may use pin-15 on 40-pin expansion header. since this is by default configured as GPIO, you should also modify pinmux spreadsheet to update the customer usage as GP_PWM1.
please refer to Changing the Pinmux section for steps to change the pinmux.

besides, you may see-also Topic 229603 regarding to PWM configuration.

17

Hello JerryChang,

Is there any pin to use on CSI connector?
I want to use them directly since I have to make another extension cable line from 40-pin expansion header.

Or do you mean that if I change pin-15 to use as pwm, then the FSYNC pins have same signal?

18

hello hscho0316,

as you can see in the NVIDIA Jetson AGX Xavier Series Camera Module Hardware Design Guide

The developer kit camera connector does not have a pin with PWM capability.

so,
if FSYNC must be a periodic signal but does not need high accuracy (in terms of jitter),
you may use GPIO signal (the 120-pin camera connector) of AGX Orin developer kit.
please check design guide, [Table 3-3. GPIO Pin Description] for more details.

19

Hello JerryChang,

Oh, I didin’t notice that.
Thank you for the information.

21

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