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Setup

Environment

  • Raspberry Pi Zero
  • Raspberry Pi Camera V2
  • Raspberry Pi OS Lite

Setup of the OS

Raspberry Pi Imager enables brief preparation for booting Raspberry Pi OS.

Steps for writing an OS image to micro SD

  1. Install Raspberry Pi Imager.
  2. Open Raspberry Pi Imager.
  3. Select Raspberry Pi OS Lite (32bit) as OS.
  4. Select a SD card the OS is written in.
  5. Click WRITE.

raspi-imager

Essential system setttings in raspi-config

Users can configure some essential settings using raspi-config. raspi-config can be executed by the command (note that it should be executed as the root user):

sudo raspi-config

raspi-config enables users to configure settings interactively, showing the interface like below:

raspi-config

Users of obcam should configure:

  1. WiFi setting for network connection.
  2. Enabling legacy camera support.

Rebooting after configuration.

Most configuration in the raspi-config requires rebooting. Thus, you should reboot the system before executing the flight camera application.

WiFi setting

In the raspi-config interface,

  1. Select System Options.
  2. Select Wireless LAN.
  3. Select your country (e.g. JP Japan).
  4. Enter SSID.
  5. Enter passphrase.

Tethering

Tethering by your smart phone is a good choice for WiFi access point and router. If you want to use tethering, you enter its SSID and passphrase while the setting above.

Enabling legacy camera support

In the raspi-config interface,

  1. Select Interface Options.
  2. Select Legacy Camera.
  3. Select Yes.
  4. Select OK.

Legacy camera support

The latest version of Raspberry Pi OS supports new camera interface using libcamera, so it deprecates using legacy camera support. But picamera, which is a Python module for using Raspberry Pi Camera and used in obcam, is implemented using the legacy camera interface. Therefore, you should enable it.

Brief setup for the flight camera mode

Using this method, you can install obcam and activate the flight camera mode simultaneously. The brief setup gets under way using the script install.sh in the repository. If you want to know the steps of activation of the flight camera mode, see the section

First you should download the repository using git clone (which requires network connection):

git clone https://github.com/FROM-THE-EARTH/obcam.git

And then, you can execute the brief setup like below:

cd obcam
sudo ./install.sh

That's all setup of the flight camera mode of obcam. You can reboot the Raspberry Pi and run the flight camera program.

Installation of git

If git is not installed in the system, you can run the commands below and install git:

sudo apt update
sudo apt install git

Install only obcam module

obcam can be installed using pip.

pip install git+https://github.com/FROM-THE-EARTH/obcam.git

After the installation, you can use the obcam command to start the flight camera application.

If pip is not installed in the system

Right after the first booting of Raspberry Pi, pip might be not installed yet. In the situation, you can install pip following the procedures below:

  1. Download the script to install pip. After the command below is executed, the script get-pip.py is to be downloaded in the current directory. 
    wget https://bootstrap.pypa.io/get-pip.py
  2. Execute the script get-pip.py. 
    python get-pip.py

Activate the flight camera mode

About the flight camera mode

In the flight camera mode, the application of the flight camera automatically starts when booting a Raspberry Pi. To activate the flight camera mode, the procedures below is required:

  1. Network and camera settings.
  2. Install obcam.
  3. Writing a gileum file for the flight camera.
  4. Activate the flight camera mode.

Writing a gileum file

Gileum files are kinds of setting files of the application. You should write a gileum file glm.py before activation of the flight camera mode. The gileum file glm.py is in the repository, so you can overwrite the file after downloding the repository. Details of the setting parameters are written in the page. But please note that the settings are already done in the glm.py when downloading the repository, so you doesn't have to change the settings if there are no certain reasons.

Just activate the flight camera mode

Using the script scripts/activate_flightcam.sh, you can activate the flight camera mode. The scripts/activate_flihgtcam.sh is also in the repository.

sudo ./scripts/activate_flightcam.sh

Update obcam

Update just obcam

You can update obcam following commnd:

pip install --upgrade git+https://github.com/FROM-THE-EARTH/obcam.git

Update obcam and activate the flight camera mode

  1. Delete the local repository: 
    rm -rf obcam/
  2. Follow the operations referencing the section

Details of the activation

In this section, details of the activate process is described. The process is not complicated so much. The point is to update the /etc/rc.local file in the system. The file /etc/rc.local is a shell script to be executed at booting.

The script scripts/activate_flightcam.sh inserts the line to /etc/rc.local, in order to execute the obcam program like that:

# /etc/rc.local

# Some lines ...

/usr/bin/python -m obcam /usr/local/src/obcam/glm.py
exit 0

As you can see, the obcam program is executed giving the gileum file /usr/local/src/obcam/glm.py, which is copied when executing scripts/activate_flightcam.sh. Therefore, there is no effects in terms of the flight camera application if you change the content of the glm.py in the downloaded repository, because obcam refers /usr/local/src/obcam/glm.py. If you want apply the change of the glm.py in the downloaded repository, just run scripts/activate_flightcam.sh again, or copy the glm.py to /usr/local/src/obcam/glm.py.