Streaming MIPI Color Camera with RPI4 Through GStreamer & Control Through V4L2

This document describes the complete procedure to interface and stream video from the BOLT-1335CRA camera module using Raspberry Pi 4. 

The process includes: 

• Installing required utilities 

• Adding device tree overlay files 

• Compiling kernel overlays 

• Installing the camera driver 

• Loading firmware 

• Streaming video using GStreamer 

The steps must be followed sequentially to ensure the camera is detected and streamed correctly. 

Hardware Requirements 

Before starting the setup, ensure the following hardware components are available. 

Component	Description
BOLT-1335CRA Camera Module	Camera module used for image capture and streaming
Raspberry Pi 4	Embedded processing platform used to interface and stream the camera
Micro SD Card (32GB / 64GB)	Used to install Raspberry Pi OS and store required files
15 cm FFC Cable	Flat Flexible Cable used to connect the camera module to the Raspberry Pi CSI interface
External Display Monitor	Required to view the Raspberry Pi desktop environment and camera streaming output

Hardware Connection 

• Insert the Micro SD card (32GB / 64GB) with Raspberry Pi OS into the Raspberry Pi 4. 

• Connect the BOLT-1335CRA camera module to the Raspberry Pi CSI camera port using the 15 cm FFC cable. 

• Ensure the FFC cable orientation is correct and firmly inserted on both the camera and Raspberry Pi connectors. 

• Connect the Raspberry Pi 4 to an external display monitor using HDMI. 

• Connect a keyboard and mouse if required. 

• Power on the Raspberry Pi. 

Once the hardware setup is completed, proceed with the software configuration steps described in the following sections. 

Installing Required Utility 

Before starting the camera integration, install gedit, which will be used to edit configuration files and Makefiles. 

• Install the gedit library using the following command: 

sudo apt install gedit 

Copy DTBO File 

• To interface BOLT-1335CRA with RPI-4, download the dtbo file. 

• The downloaded dtbo file must be copied into the /boot/overlays directory using the following command. 

sudo cp BOLT_1335CRA.dtbo /boot/overlays 

Configure Raspberry Pi Boot Settings 

• Navigate to the /boot/firmware directory and open the config.txt file. 

cd /boot/firmware  

sudo nano config.txt  

• Add the following line at the end of the config.txt file. 

dtoverlay=BOLT_1335CRA,media-controller=0 

• Press Ctrl + S to save and Ctrl + X to exit the editor. 

The config.txt file controls hardware initialization during Raspberry Pi boot. 

The line dtoverlay=BOLT_1335CRA,media-controller=0 loads the BOLT-1335CRA camera overlay and configures the driver to operate in standard V4L2 mode. 

Verify I2C Nodes 

• Power off and then power on the Raspberry Pi to verify whether the I2C nodes are generated. 

• Use the following command: 

ls /dev/i2c-* 

• The output should look similar to the following. 

/dev/i2c-0  /dev/i2c-1  /dev/i2c-10  /dev/i2c-20  dev/i2c-21  dev/i2c-22 

• I2C nodes indicate that the camera control interfaces have been initialized successfully. 

• The driver communicates with the image sensor and other camera components through the I2C bus. 

Adding Firmware (BIN File) 

• Download the firmware package and extract it. 

• The extracted package will contain the file: BOLT_1335CRA.bin 

• Copy the firmware file into the /lib/firmware directory. 

sudo cp BOLT_1335CRA.bin /lib/firmware 

sync 

• The .bin file contains sensor firmware or configuration parameters required by the camera driver during initialization. 

• /lib/firmware is the standard Linux location where device drivers retrieve firmware files during runtime. 

Update Boot Configuration 

• Navigate to the firmware directory and open the config.txt file again. 

cd /boot/firmware  

sudo nano config.txt  

• To stream BOLT-1335CRA, comment the following line if it is present: 

camera_auto_detect=1

• Press Ctrl + S to save and Ctrl + X to exit. 

• camera_auto_detect enables the Raspberry Pi's default camera detection mechanism. Since the BOLT-1335CRA uses a custom driver, this option must be disabled to prevent conflicts. 

Reboot the Raspberry Pi 

• Restart the Raspberry Pi to apply the configuration changes. 

reboot 

• Alternatively, power off and power on the Raspberry Pi. 

Install GStreamer 

• If GStreamer is not installed, install it using the following command. 

sudo apt-get install gstreamer1.0-tools 

Load the Camera Driver 

• Download the driver package and extract it to the home directory. 

• Open the terminal and navigate to the directory containing the driver file. 

• Load the driver using the following command. 

sudo insmod BOLT_1335CRA_v1_6.ko 

• insmod inserts the kernel driver module into the Linux kernel. 

• After successful initialization, the camera will typically appear as: /dev/video0 

Stream Video from BOLT-1335CRA 

The camera supports the following output resolutions. 

Resolution	Aspect Ratio
640 × 480	4:3
1280 × 720	16:9
1920 × 1080	16:9
2600 × 1952	4:3
3840 × 2160	16:9
4208 × 3120	4:3

• Use the following GStreamer pipeline to stream video from the camera at VGA resolution. 

gst-launch-1.0v4l2srcdevice="/dev/video0"!videoconvert!video/x-raw,framerate=30/1,width=640,height=480,pixelformat=UYVY  ! autovideosink 

Supported UVC / V4L2 Controls 

• The BOLT-1335CRA camera supports the following UVC compatible V4L2 controls. 

Control	Type	Minimum	Maximum	Default
Brightness	Integer	-15	15	0
Contrast	Integer	0	30	3
Saturation	Integer	0	60	18
White Balance Automatic	Boolean	0	1	1
White Balance Temperature	Integer	1000	10000	4500
Horizontal Flip	Boolean	0	1	0
Vertical Flip	Boolean	0	1	0
Auto Exposure	Menu	0	1	0
Exposure Time Absolute	Integer	1	10000	625

1. Brightness Control 

• Brightness adjusts the overall luminance of the image. 

Parameter	Value
Minimum	-15
Maximum	15
Step	1
Default	0

Example Command 

v4l2-ctl --device=/dev/video0 --set-ctrl=brightness=5 

• Increasing the value makes the image brighter. 

• Decreasing the value darkens the image. 

2. Contrast Control 

• Contrast controls the difference between the brightest and darkest parts of the image. 

Parameter	Value
Minimum	0
Maximum	30
Step	1
Default	3

Example Command 

v4l2-ctl --device=/dev/video0 --set-ctrl=contrast=10 

• Higher contrast improves visibility of edges and details. 

3. Saturation Control 

• Saturation controls the intensity of colors in the image. 

Parameter	Value
Minimum	0
Maximum	60
Step	1
Default	18

Example Command 

v4l2-ctl --device=/dev/video0 --set-ctrl=saturation=25 

• Low saturation → dull colors 

• High saturation → vivid colors 

4. Auto White Balance 

• Auto white balance adjusts the image color automatically based on lighting conditions. 

Example Command 

• Enable Auto White Balance 

v4l2-ctl --device=/dev/video0 --set-ctrl=white_balance_automatic=1 

• Disable Auto White Balance 

v4l2-ctl --device=/dev/video0 --set-ctrl=white_balance_automatic=0 

• When enabled, the camera automatically adjusts color temperature to maintain natural color reproduction. 

5. Manual White Balance Temperature 

Manual white balance allows direct control of the color temperature. 

Parameter	Value
Minimum	1000
Maximum	10000
Step	500
Default	4500

Example Command 

v4l2-ctl --device=/dev/video0 --set-ctrl=white_balance_temperature=5000 

• Lower values represent warmer tones (yellow/red), while higher values represent cooler tones (blue). 

6. Horizontal Flip 

Horizontal flip mirrors the image across the vertical axis. 

Example Command 

v4l2-ctl --device=/dev/video0 --set-ctrl=horizontal_flip=1 

• This is useful when the camera is mounted in a mirrored orientation. 

7. Vertical Flip 

Vertical flip mirrors the image across the horizontal axis. 

Example Command 

v4l2-ctl --device=/dev/video0 --set-ctrl=vertical_flip=1 

8. Auto Exposure Control 

The camera supports both automatic and manual exposure modes. 

Example Command 

• Enable Auto Exposure 

v4l2-ctl --device=/dev/video0 --set-ctrl=auto_exposure=0 

• Enable Manual Exposure 

v4l2-ctl --device=/dev/video0 --set-ctrl=auto_exposure=1 

• Auto Mode → Camera automatically adjusts exposure based on lighting. 

• Manual Mode → Exposure must be manually controlled. 

9. Exposure Time Control 

Exposure time defines the amount of time the sensor collects light for each frame. 

Parameter	Value
Minimum	1
Maximum	10000
Step	1
Default	625

Example Command 

v4l2-ctl --device=/dev/video0 --set-ctrl=exposure_time_absolute=1000 

 Important Note 

This control becomes active only when manual exposure mode is enabled.