YUV Sensor (MediaTek Imgsensor)

Important

All the bash commands shown here are based on Genio 510/700-EVK. For Genio 510-EVK, users can follow the same step to do the whole setup by changing the naming term from 700 to 510.

Note

All command operations presented in this chapter are based on the IoT Yocto v24.0, Genio 700-EVK and Onsemi AP1302 ISP and AR0830 sensor. You might get different operation results depending on the platform you use.

Camera Package And Specification

The YUV camera DTB for Genio 510/700-EVK is CAM DTB-D6. It contains an Onsemi AP1302 ISP and an AR0830 Sensor.

Camera DTB D6 - Onsemi AP1302 ISP and AR0830 Sensor

Connect The Camera To The EVK

There are 2 MIPI-CSI sockets on Genio 510/700-EVK, which are CSI0, and CSI1. In the following figure, the camera DTB is connected to the CSI0 socket.

Connect Camera DTB D6 to Genio 510/700-EVK

The hardware connection is AR0830 ---> AP1302 ---> MIPI-CSI On EVK. The camera daughter board can be configured in ISP mode and Bypass mode. In ISP mode, the images from the AR0830 camera module are passed to AP1302 ISP before being received by the EVK. In Bypass mode, the images from the AR0830 camera module are transferred to the EVK directly. By default, IoT Yocto only supports ISP mode.

To configure the camera DTB D6 to ISP mode, you MUST set 6 jumpers and 1 camera sensor as shown in the figure below. The jumpers MUST be correctly set and the camera sensor MUST be connected to the CAMERA 0 slot.

Camera DTB D6 - ISP mode

Warning

Please make sure all the above settings, including the jumpers, camera slot, and MIPI-CSI socket, are correct. Otherwise, the I2C connection between the sensor, ISP, and SoC will fail.

Select Camera Device Tree Blob Overlay

The camera device is inactive by default, so the kernel has to load a specific device tree blob overlay to enable it. Please refer to bl33u-boot for more details.

YUV Camera DTBO for Genio 510/700-EVK

Platform	CSI0	CSI1	DTBO	Usage
Genio 510/700-EVK	AP1302+ AR0830	x	camera-ar0830-ap1302-csi0.dtbo	Enable 4-lane CAM-DTB-D6 w/ Onsemi AR0830 on CSI0
Genio 510/700-EVK	AP1302+ AR0830 (2 lane)	x	camera-ar0830-ap1302-2lanes-csi0.dtbo	Enable 2-lane CAM-DTB-D6 w/ Onsemi AR0830 on CSI0
Genio 510/700-EVK	x	AP1302+ AR0830	camera-ar0830-ap1302-csi1.dtbo	Enable 4-lane CAM-DTB-D6 w/ Onsemi AR0830 on CSI1

genio-flash --list-dtbo
List of available DTBO:
        - camera-ar0830-ap1302-2lanes-csi0.dtbo
        - camera-ar0830-ap1302-csi0.dtbo
        - camera-ar0830-ap1302-csi1.dtbo
        - ...
genio-flash --load-dtbo camera-ar0830-ap1302-csi0.dtbo --load-dtbo gpu-mali.dtbo --load-dtbo apusys.dtbo --load-dtbo video.dtbo

Warning

Please select the DTBO according to the CSI slot to which the camera sensor is connected. For example, if the camera is connected to the CSI0 slot, please load the dtbo camera-ar0830-ap1302-csi0.dtbo. Otherwise, the camera initialization will fail.

Supported Formats And Sizes

Platform	Sensor	Stream Type	Size	Frame rate	Format	MIPI Lanes
Genio 510/700-EVK	Onsemi AP1302 & AR0830	Preview	1920x1080	30	UYVY	4
Genio 510/700-EVK	Onsemi AP1302 & AR0830	Preview	2560x1440	30	UYVY	4
Genio 510/700-EVK	Onsemi AP1302 & AR0830	Preview	3840x2160	24	UYVY	4
Genio 510/700-EVK	Onsemi AP1302 & AR0830	Preview	1920x1080	30	UYVY	2
Genio 510/700-EVK	Onsemi AP1302 & AR0830	Preview	2560x1440	30	UYVY	2
Genio 510/700-EVK	Onsemi AP1302 & AR0830	Preview	3840x2160	12	UYVY	2

Note

The supported format, resolution, and frame rate are related to the capability of the sensor and SoC.

V4L2 Device Node

Camera ISP is a complicated feature that has a large number of device nodes. The camera ISP driver creates 130 video devices in total.

• MTK-ISP-DIP-V4L2 has 73 devices

• mtk-cam has 56 devices

• mtk-v4l2-camera has 1 device

MTK-ISP-DIP-V4L2 and mtk-cam are used by the camera ISP middleware. The user can just focus on mtk-v4l2-camera which is for streaming.

v4l2-ctl --list-devices
...
mtk-cam (platform:16000000.camisp):
        (56 video devices)
        /dev/media0

mtk-v4l2-camera (platform:mtkcam0):
        /dev/video74

Launch Camera

The V4L2 nodes with the name mtk-v4l2-camera can be used for streaming. For the YUV sensor, there’s only 1 V4L2 device which is for the preview stream. The user can find the devices by the following command:

v4l2-ctl --list-device
mtk-v4l2-camera (platform:mtkcam0):
        /dev/video74
cat /sys/class/video4linux/video74/name
mtk-v4l2-camera@0-Preview

Important

The above v4l2 device node number is for example. The node number may change every time the system boots.

To quickly fetch the correct node and assign the environment variable:

declare -a VIDEO_DEV=(`v4l2-ctl --list-devices | grep mtk-v4l2-camera -A 1 | grep video | tr -d "\n"`)
printf "Preview Node\t= ${VIDEO_DEV[0]}\n"
Preview Node    = /dev/video74

Section Supported formats and Sizes shows the supported formats and sizes. The user can also use the v4l2 utility, v4l2-ctl, to list formats.

v4l2-ctl -d ${VIDEO_DEV[0]} --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
        Type: Video Capture Multiplanar

        [0]: 'UYVY' (UYVY 4:2:2)
                Size: Discrete 1920x1080
                        Interval: Discrete 0.033s (30.000 fps)
        ...

To launch the camera, the user can use v4l2-ctl, gst-launch-1.0, or other V4L2 applications.

• Use v4l2-ctl

  v4l2-ctl -d ${VIDEO_DEV[0]} --set-fmt-video=width=1920,height=1080,pixelformat=UYVY --stream-mmap --stream-count=10 --stream-to=/tmp/ap1302.yuv --verbose
  

• Use gst-launch-1.0

  gst-launch-1.0 v4l2src device=${VIDEO_DEV[0]} ! video/x-raw,width=1920,height=1080,format=UYVY ! v4l2convert output-io-mode=dmabuf-import ! video/x-raw,width=1280,height=720 ! waylandsink sync=false
  

  

  Show Preview stream on Weston

Note

To use MediaTek video codec and MDP hardware, the user has to load video.dtbo. For more details, please refer to Genio 510/700-EVK Video Codec.

Sensor Launch Time

For the launch time of the Onsemi AP1302 ISP and AR0830 sensor. Please refer to Sensor Launch Time.