This repository is a fork of buildroot (https://buildroot.org/) intended to be used with a python tool named opencv-home-cam, to create a simple home surveillance system on a Raspberry Pi 3.
OpenCV and Python3 are added as well as the opencv-home-cam tool.
opencv-home-cam is a simple object detection framework/wrapper built on top of OpenCV.
See the opencv-home-cam git repository for more details:
https://github.com/erstrom/opencv-home-cam
OpenCV is the computer vision library used by opencv-home-cam:
Everything needed to build the entire system is included (directly or indirectly) in this repository (depending packages will be fetch automatically from the internet).
For more information about buildroot, please consult the official buildroot documentation:
https://buildroot.org/downloads/manual/manual.html
Below are step-by-step instructions for building an SD-card image containing opencv-home-cam and its dependecies (basically Python3 and OpenCV) for a Raspberry Pi 3.
Clone the buildroot-opencv git repository:
git clone https://github.com/erstrom/buildroot-opencv.git
The default branch is the recommended branch to use and thus, there is no need to checkout a custom branch.
Note that the default branch is not master which is normally used as default in most git repositories. Instead the default branch is rpi-opencv-dev. The master branch will be identical to the official buildroot master.
Use the defconfig raspberrypi3_opencv_home_cam_defconfig as a starting point for the configuration. It contains all the necessary configuration options needed to run opencv-home-cam on a Raspberry Pi 3.
cd buildroot-opencv make raspberrypi3_opencv_home_cam_defconfig
Some of the settings need to be customized. These settings are:
- Network configuration: wired or wireless?
- Settings for the opencv-home-cam action scripts: email addresses etc.
Run make menuconfig in order to start the interactive configuration:
make menuconfig
Typically, the device will use DHCP to obtain an IP address on the network (this is by far the most common setup in a home network).
Since the Raspberry Pi 3 has both wired and wireless support, we must select which interface to use when obtaining an IP address.
The alternatives are:
- eth0 (wired)
- wlan0 (wireless)
The interface to use with DHCP is selected under:
System configuration -> Network interface to configure through DHCP
Change the name of the network interface to either eth0 or wlan0.
The buildroot configuration option is: BR2_SYSTEM_DHCP (in case you
want to edit .config or configs/raspberrypi3_opencv_home_cam_defconfig
manually).
Most wireless home networks use WPA/WPA2 PSK security and we assume this is the case here as well.
If the wireless network interface is to be used, we must add the security credentials manually.
This is done by generating a wpa_supplicant configuration file and add it to the rootfs overlay.
The easiest way of adding the configuration file is to generate it with wpa_passphrase:
wpa_passphrase <network ssid> <passphrase> \
> board/raspberrypi/rootfs-overlay-opencv-home-cam/etc/wpa_supplicant.conf
wpa_passphrase takes the SSID and passphrase as arguments and writes the configuration to stdout.
The opencv-home-cam action script configuration is done under:
Target packages -> Interpreter languages and scripting -> python3 -> External python modules -> python-opencv-home-cam
The detector type can be selected under Detector to use.
The below screenshot shows a selection where the simple motion detector
is used. The simple motion detector detects motion by diffing consecutive
frames from the camera.
The sendemail action action is enabled by selecting:
Enable sendemail action
The configuration parameters for this action are presented below:
- From-address
- To-address
- SMTP server
- SMTP password
See example-actions/sendemail.sh in opencv-home-cam.git for a more detailed explanation of the options.
Once the system is configured properly it is time to build.
To build an SD-card image, just run make:
make
Buildroot will download and build all packages and create the SD-card image in one step.
The build will take some time (~40-60 minutes depending on the build machine).
The output will be available in output/images
Several files will be created, but we only need the SD-card image: output/images/sdcard.img
Write the image to the SD-card with dd:
dd output/images/sdcard.img /dev/sdX
/dev/sdX should be replaced with the path to the SD-card device.