Setting up your Raspberry Pi (Assume Pi 3 Model B+)

All the steps below are performed on a Mac, but it should work with any OS of your choice!

This is the very first step as you need to prepare the SD card with the raspberry operating system. We wil use Etcher for this purpose. Just download Etcher for your operating system and follow the steps below:

1. Format the SD card! You should know how to do this!

2. Head on to the Raspberry website and download the latest version of the OS! You might want to consider the headless version to save some space and memory when running on your RasPi

3. Open Etcher and just flash the SD card with the Raspberry OS that you just downloaded

4. Insert the SD card on to your RasPi and it is now time to boot it up!

5. You now have to set up the WiFi password (Assuming that you are using Pi 3 Model B+ which has a built in WiFi module). Do the following:

   Type the following in the command line:

   sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
   

   Now, just add the following to the conf file. Refer your router for the ssid and psk details!

   network={
        ssid="The_ESSID_from_earlier"
        psk="Your_wifi_password"
   }
   

6. I normally prefer to change the default user and password to something to my liking! You can skip this step if you wish to work with the defaults! If in case, you wish to change the default user and password do the following steps:

   Enable root login by giving the following command

   sudo passwd root
   

   Logout of the pi user

   logout
   

   Now Login back in as the user 'root' using the password you just created. Now we can change the default user for the raspberry pi using the following command

   usermod -l newusername pi
   

   Now we have to also change the user's default home directory to reflect this new user! The command below should do that

   usermod -m -d /home/newusername newusername
   

   Logout and Login again with this new user and change the password for this new user! That's it!

Set up Docker in Raspberry Pi

Since all installations (Python, OpenCV) here are encapsulated in a Dockerfile, we need to install Docker!

Installing Docker in Raspberry Pi is pretty simple. Just open a terminal and run the following command:

curl -fsSL get.docker.com -o get-docker.sh && sh get-docker.sh

Optionally to run Docker without sudo, do the following:

1. Add a Docker group if it does not exist

sudo groupadd docker

2. Add the connected $USER to the docker group where $USER could be th current user

sudo gpasswd -a $USER docker

3. Run newgrp command so that the changes take effect

newgrp docker

4. Check if it worked

docker run hello-world

If it worked, you should see "Hello from Docker" printed out!

Installing Python and OpenCV

This step is fairly simple as you just have to build or run a Docker image! Yes, you have two choices here!

Either pull and run the docker image that is already created or use the source Dockerfile and build the image for yourself! You have to know that building the image with OpenCV is not a task that is done within minutes. On my Raspberry Pi Model 3 B+, it took me about 3 hours to fully build the image. So if you are looking for a quicker install, just grab the docker image from my docker hub repo from here

You probably need to first have the following components with you!

1. A Raspberry Pi - I prefer to use the Model 3 B+ that has a built in WiFi

2. A Pi Camera - I got the Raspberry Pi v2.1, 8 MP NoIR camera as this one can take pictures in the dark provided it has an IR filters

3. A proper case to protect the Pi and the camera. I ordered a RasPi camera case from ModmyPi. If you are going to mount the setup outdoors, you might also want to consider the following factors:

   3.1 How are you going to get WiFi coverage at the outdoor location 3.2 How are you going to get the Power supply to the Pi 3.3 Would the case tolerate harsh weather conditions

So for me, it was just going to be mounted indoors. So I should be fine with the ModMyPi case for now!

Here is a snapshot of my Pi assembled with the camera! Note that I have a PIR sensor as well, but I'm not using it for the moment!

Once everything is assembled, check if the camera is working using the following command on your Pi

```
raspistill -o output.jpg
```

Ok! So if you are thus far here, then proceed to building your OpenCV Docker image. Click here for the instructions.