TI Starter Kit EVM Board TEVS Camera Usage Guide

Introduction

This article guides you how to get started using TechNexion camera modules on Ti starter kit.

Supported Camera Modules

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Overview

• Supported Ti Developer Kit
• Prepare for TechNexion cameras
• Using TechNexion Pre-built Image
• Instructions for Testing Camera
• Troubleshooting

Supported Ti Developer Kit

• Ti SK-AM62X
• Ti SK-AM62A-LP
• Ti SK-TDA4VM

Prepare adapter board and cable for TechNexion cameras

With different board you need  prepare match adapter board and cable for the connect pins.
Here is the table for you can easily to confirm what you need for your solution.

Follow this demo video to connect adapter and cable to the CSI connector on board.

Using TechNexion Pre-built Image

The Pre-built image contains the required device tree blobs and camera drivers to enable TechNexion TEVS Series cameras. It can be available for download via TechNexion's server.

SK-AM62X Image Download Link

SK-AM62A Image Download Link

SK-TDA4VM Image Download Link

Instructions for Testing Camera

Specify Camera DTB in uEnv.txt

1. Find 'uEnv.txt' file in SD card which you flash the image.

# Open on SK-TDA4VM, the directory should be here:
$ /run/media/BOOT-mmcblk1p1/uEnv.txt
# Open on HOST-PC, the directory should be here:
$ /media/username/BOOT/uEnv.txt

2. Add camera dtb  specifies the 'name_overlays' variable in uEnv.txt.

#SK-AM62X
   name_overlays= k3-am625-sk-csi2-tevs.dtbo
#SK-AM62A
   name_overlays= k3-am62a7-sk-csi2-tevs.dtbo
#SK-TDA4VM
   name_overlays= k3-j721e-sk-tevs.dtbo

Start Camera Video Stream via Gstreamer

We can check whether camera have been link via v4l2 control command :

$ v4l2-ctl --list-device

Get the device number of camera capture device.

# CSI 0 (cam1) 
j721e-csi2rx (platform:4504000.ticsi2rx):
       /dev/video{X}
       
# CSI 1 (cam2) 
j721e-csi2rx (platform:4510000.ticsi2rx):
       /dev/video{X}

The following is example.

Specify the capture device you just get (/dev/video2) and start gstreamer to get video stream with 640x480 on the display :

$ gst-launch-1.0 v4l2src device=/dev/video2 ! video/x-raw,width=640,height=480 ! waylandsink sync=false

Troubleshooting

Cannot Run Edge AI Demo Application

The Pre-built image build on Ti, so the initial demo application doesn't include TechNexion's cameras. you can disable this system service and call the Weston desktop again.

$ systemctl disable edgeai-init.service
$ systemctl restart weston
$ reboot

Find out the Camera

Boot up SK-TDA4VM and check initialization of camera driver.
it shows below messages, the driver is initialized correctly. If the drivers haven't been probed, please check the connector plugin correct.

$ dmesg -t | grep tevs

root@tda4vm-sk:/opt/edgeai-gst-apps# dmesg|grep tevs
tevs 7-0048: tevs_probe() device node: tevs@48
tevs 7-0048: Version:24.8.0.1
tevs 7-0048: Product:TEVS-AR0234, HeaderVer:3, MIPI_Rate:800
tevs 7-0048: probe success

And then try to using media-ctl framework to print the device topology from camera to CSI and the end to video device node.

$ media-ctl -d /dev/media1 -p

We can get which v4l2-subdev is camera in this print message and then we can use v4l2-ctl by it.

Change Resolution

For kernel 6.1 architecture you cannot easily change resolution in gsteamer pipeline. You must need to using v4l2-ctl to do this.

1. Check camera supported resolutions via v4l2-ctl

v4l2-ctl -d /dev/v4l-subdev2 --list-subdev-framesize pad=0

root@tda4vm-sk:/opt/edgeai-gst-apps# v4l2-ctl -d /dev/v4l-subdev2 --list-subdev-framesize pad=0
ioctl: VIDIOC_SUBDEV_ENUM_FRAME_SIZE (pad=0,stream=0)
Size Range: 640x480 - 640x480
Size Range: 1280x720 - 1280x720
Size Range: 1920x1080 - 1920x1080
Size Range: 1920x1200 - 1920x1200

2.Set Format

media-ctl --set-v4l2 "'tevs 7-0048':0 [fmt:UYVY8_2X8/1280X720@1/30 field:none]"