GMSL Connection between Camera and PX2

Dear Sir/Mdm,

I have the following questions regarding Fakra Cable Assembly that will carry GMSL signal between camera and PX2 Drive board.

  1. Which plug code type to use (A,B,C……) for each end (camera --> PX2 ) respectively?

  2. What is the recommended cable type (Coax/Twisted pair) ? Please share cable specifications as well

Thanks you for your attention…

BTW , it is possible to attach documents (pptx or pdf files) if needed during Q&A? Sometimes using diagrams will help in explaining queries…

Hello AL-AMR,

Please find below link for your questions. You can get more information via below link. Thanks.

Dear Sir/Mdm,

I understand that power is carried over Coax cable to GMSL camera.
What it is maximum length of cable allowable between PX2 Drive and GMSL camera?

Hello AL-AMR,

15meters. That’s the GMSL spec from Maxim. Thanks.

Dear Sir/Mdm,

I am facing the following issue with using GMSL camera with PX2.

Test Setup as follows

  1. GMSL Camera SF3323 Camera Module Assy
  2. GMSL cables of length 13 m and 15 m respectively

https://www.pasternack.com/fakra-jack-fakra-jack-pe-c100-cable-assembly-pe38746z-p.aspx
(Cable specs as according to sample received with PX2)

  1. PX2 running Nivdia sample code“ sample_camera_gmsl “

Observation

With 15 meter cable, I observe “Video freeze after a short while (directly timeout)”
With 13 meter cable, I observe " PX2 hang up (directly timeout)"
With <10 meter cable, no issue observed

Please advise solution…
Please advise what cable specs can support upto 15 meter application.

Regards
Ally Amir

Dear Sir/Mdm,

To add on , we are testing video capture at 30 frames per second…

Thank you for your attention

Hello AL-AMR,

GMSL spec is 15meters from MAXIM however the spec for DPX2 is 12 meters.
Could you please refer to DPX2 datasheet? Thanks.

Dear Sir/Mdm,

In my application I need to be able to run GMSL cables upto 15m (due to vehicle size).

Can you recommend some GMSL repeater equipment that I can use ?

Thank you for your attention.

Hello AL-AMR,

Could you please let me know which camera is being used and do you have vendor/spec of the cable? Thanks.

Hi,

a)Camera : LI-AR0231-GMSL 1080p HDR GMSL Serial Camera from Leopard Imaging

https://www.leopardimaging.com/LI-AR0231-GMSL.html

These were the cameras that came together with Drive PX2 computer

b)GMSL Cable : Water Blue FAKRA Jack to FAKRA Jack Cable Using PE-C100-LSZH Coax

https://www.pasternack.com/images/ProductPDF/PE38746Z.pdf

We ordered various lengths of GMSL cable, in summary
With 15 meter cable, we observe “Video freeze after a short while (directly timeout)”
With 13 meter cable, we observe " PX2 hang up (directly timeout)"
With <10 meter cable, no issue observed

Hello AL-AMR,

Did you enable the pre-amp setting on the serializer(camera module GMSL Tx) during the cable testing?
This can be done by writing register 0x6 (pre-emp setting) of address 0x40 (serializer addr).
Could you please re-test it after enable the pre-emphasis and setting it at 6dB on the camera’s serializer?
Please see below commands for settings. Thanks.

The register can be access thru i2c. So please do have to start the capture first in order to make sure the camera module is power on and the GMSL reverse control channel is available.

If you are running our Linux PDK, i2c utility should already be available. Using another terminal while the capture is on-going, you can enter the i2c utility command as below to check and/or enable pre-emphasis on the camera’s serializer:

To check the pre-emphasis setting on the camera’s serializer for GMSL group A:
i2cget -f -y 7 0x40 0x6

To enable the pre-emphasis and setting it at 6dB on the camera’s serializer for GMSL group A:
i2cset -f -y 7 0x40 0x6 0xac

For GMSL group B – use above command but replace highlighted number to “2”
For GMSL group C – use above command but replace highlighted number to “1”

@SteveNV, could you tell me where GMSL camera control via I2C documents are? I got lost on these magic numbers,
To enable the pre-emphasis and setting it at 6dB on the camera’s serializer for GMSL group A:
i2cset -f -y 7 0x40 0x6 0xac

We are trying to find a way to synchronize 8 GMSL cameras (AR0231) with a 16-beam LIDAR. Please let us know if you have any sample config. Also is it possible to change cameras’s focus/exposure on the fly?

thanks a lot and have a good day,

Steve

Dear scheng,

Could you please help to check the following doc for your topic?

https://docs.nvidia.com/drive/nvvib_docs/index.html#page/NVIDIA%20DRIVE%20Linux%20SDK%20Development%20Guide%2Fipp_framework.html

And if you check out:
file:///usr/local/driveworks/doc/nvdwx_html/dwx_recording_library.html

There should be:
The params must follow the params given to a Driveworks sensor at initialization. In order to record in other formats besides h264, add output-format=[raw,lraw,h264,raw+h264,lraw+h264] with one of the listed output formats to the params. In order to record camera frames at a lower rate than the default, use frame-skip-count in the params.
For example, a value of frame-skip-count=1 records at 15 FPS if the camera hardware runs at 30 FPS. Setting record-frame-count=2 with frame-skip-count=1 records two (2) frames and skips 1, and then repeats.

For certain kinds of camera, e.g., ar0231-rccb, the camera framerate can be controlled by the required-framerate option. Valid values for now are 20, 30, and 36.

Hi SteveNV, thanks for the link. Right now we don’t worry too much about FPS. We want to change exposure, analog/digital gain, and ISO(?) on the fly. Not sure what’s the current status on PX2 cameras…

thanks,

Steve

Dear Steve,

Could you please refer to the following links?

Image Capture Calibrate (nvmimg_cc)
https://docs.nvidia.com/drive/nvvib_docs/index.html#page/NVIDIA%20DRIVE%20Linux%20SDK%20Development%20Guide%2FMultimedia%2Fnvmedia_nvmimg_cc.html

NvMedia IPP Framework
https://docs.nvidia.com/drive/nvvib_docs/index.html#page/NVIDIA%20DRIVE%20Linux%20SDK%20Development%20Guide%2Fipp_framework.html

https://docs.nvidia.com/drive/nvvib_docs/NVIDIA%20DRIVE%20Linux%20SDK%20Development%20Guide/baggage/structNvMediaIPPPropertyControls.html#afac91f638fc337afb27c7fe1a2209db3

Thanks, SteveNV.

I read about Image Capture Calibrate (nvmimg_cc) earlier this week but I couldn’t find this program on my PX2. There is one, /root/vibrante-t186ref-linux/samples/nvmedia/img_cc/nvmimg_cc, but it’s not compiled for ARM on PX2. Do you know where is the source code? Also my understanding is that nvmimg_cc can change camera configuration before using it. We can’t change camera configuration such as exposure on the fly. Is my understanding correct?

Have a good day,

Steve

Dear scheng,

Could you check below folder on DPX2 for Image Capture Calibrate(nvmimg_cc)?
/home/nvidia/driver_t186ref-linux/samples/nvmedia/img_cc/

We can’t change camera configuration such as exposure on the fly. Is my understanding correct?

Yes, correct.

Hi SteveNV,

thanks for the confirmation and link!

Steve

Hi~
Here is my sample_camera_gmsl’s output on DPX2.

The .h264 files I recorded looks the same.
It is affected by illumination condition as you can see in the picture.
When the lighting is too strong, it became like this and the detection results can be very poor.
Is there some tips for solving this? or I reply in a false discussion thread with some mistake?
Please give me some advices, thanks!