OV7251 0.3MP Global Shutter Camera for Raspberry Pi

Introduction

Global shutter cameras eliminate rolling shutter artifacts to better capture moving objects, and OV7251 is just one of them. Arducam OV7251 MIPI cameras are mainly designed for the Raspberry Pi and connected directly to its CSI connector. They support the official V4L2 camera driver and Arducam userland driver.

Models in this Series

Currently, there are 2 models in Arducam OV7251 Series. The main difference between them is the sensitivity to infrared.

• If you operate only in visible light, get B0161.
• If IR is needed in your application, get B0206.

Common Specs

The following specs applies to all products in this series.

Image sensor

Lens

Camera Board

Connector & Cable

Driver Performance (With Official V4L2 Driver)

Introduction

Arducam OV7251 MIPI Camera Module is a 0.3MP monochrome camera module with a global shutter, and it can be used on all Raspberry Pi models with a camera interface.

Setup

Hardware Setup

For Standard Raspberry Pi Models with 15-pin connector

1. Locate the camera port (CSI). It’s between the HDMI and audio port of the Raspberry Pi board.
2. Pull up on the plastic edges. Do it gently to avoid pulling it off.
3. Push in the camera ribbon. Make sure the silver contacts are facing the HDMI port. Do not bend the flex cable, and make sure it’s firmly inserted.
4. Push the plastic connector down. Do it while holding the flex cable until the connector is back in place.

For Raspberry Pi Zero and Compute Module with 22-pin connector

1. Remove the default white ribbon cable
2. Push in the gold ribbon cable to the camera board’s connector
3. Connect the Module to the Raspberry Pi Zero/Compute Module

Software Setup

For Raspberry Pi Bullseye System

• Check your system information

uname -a

System information for referring:

[email protected]:~ s uname -a
Linux raspberrypi 5.15.32-v7l+ #1538 SMP Thu Mar 31 19:39:41 BST 2022 armv7l GNU/Linux

• Modify config file

sudo nano /boot/config.txt
Add dtoverlay=ov7251,media-controller=0 under the line [all]

• Python Script

play.py

import cv2

cap = cv2.VideoCapture(0)

while True:
    ret, frame = cap.read()
    cv2.imshow("Test", frame)
    key = cv2.waitKey(1)
    if key == ord('q'):
        break

play2.py

import cv2

cap = cv2.VideoCapture(0)

cap.set(cv2.CAP_PROP_CONVERT_RGB, 0)

while True:
    ret, frame = cap.read()
    frame = frame << 6
    cv2.imshow("Test", frame)
    key = cv2.waitKey(1)
    if key == ord('q'):
        break

• Install python OpenCV apps

sudo apt install -y python3-opencv
sudo apt install -y opencv-data

• Run the camera

python3 play.py
python3 play2.py

For Raspberry Pi Buster System

1. Check your firmware support

OV7251 is not native to the Raspberry Pi kernel, so it is not supported in the older firmware. Please first confirm whether you are on a proper firmware.

• Open your Terminal with CTRL+ALT+T
• In your Terminal, type the following command then hit Enter:

ls /boot/overlays/ov7251.dtbo

If you get a successful result like the following picture, then you are good to go.

sudo apt update
sudo apt full-upgrade
sudo reboot

2. Enable OV7251 overlay for your Raspberry Pi

We will edit the config.txt to enable the OV7251 overlay.

• In your Terminal, type the following command then hit Enter:

sudo nano /boot/config.txt

Edit config.txt to add OV7251 overlay.

• Use ↓ to navigate to the bottom of the config.txt file, and
• Add the following line to it as the picture shows.

dtoverlay=ov7251

Save the change and exit.

• Press Ctrl+o to save the changes, then hit Enter
• Press Ctrl+x to exit.

After you exit Nano, go back to the Terminal and reboot so the changes can take effect.

• In your Terminal, type the following command then hit Enter:

sudo reboot

3. Check your camera device

You can list the video device node to test whether your Raspberry Pi sees this camera module.

• Open your Terminal with CTRL+ALT+T
• In your Terminal, type the following command then hit Enter:

ls /dev/video0

To take a step further, you can use the following command to know the camera runs well.

• In your Terminal, type the following command then hit Enter:
• If you get successful results, press Ctrl+C to stop the program.

v4l2-ctl --stream-mmap --stream-count=-1 -d /dev/video0 --stream-to=/dev/null

First Use

Preview the camera feed

We will use yavta to preview the camera feed. yavta stands for “Yet Another V4L2 Test Application”.

We need to clone yavta and then compile it.

• In your Terminal, type the following command then hit Enter line by line:

git clone https://github.com/6by9/yavta.git
cd yavta
make

Preview the video feed in UYUV format.

• In your Terminal, type the following command then hit Enter:
• After you’ve done with the preview, hit Ctrl+C to exit.

./yavta --capture=1000 -n 3 --encode-to=file.h264 -f UYVY -m -T /dev/video0

What’s Next

Here are the things you can do after this quick start:

• Check the Datasheet for details like pin and mechanical definition.
• Check the Application Note for applications like using Arducam userland MIPI camera drivers.
• Check other Arducam global shutter cameras like OV9281 and OV2311.
• Join the discussion in our forum.

Use OV7251 with Arducam Userland MIPI Camera Driver

Arducam is among the earliest to enable the use of OV7251 cameras on the Raspberry Pi. Before the OV7251 camera driver was officially merged to the Raspberry Pi kernel tree, there had already been Arducam drivers.

Check our userland driver SDK and examples for more details.