My brother uses an Invacare TDX wheelchair, which is easy to maneuver in all directions, but due to limited visibility to the back it is difficult to drive backwards in limited spaces. Goal of the project is to build a rear view camera using IP streaming to a mobile phone.
Needed components:
- power supply and distribution using the wheelchairs power
- rear view camera and video streamer
- mobile phone holder for the conrol pad.
Power is supplied by the wheelchair itself, which uses 24V lead batteries. The charging port is misused to plug in a power converter to USB, which powers the Raspberry which does the streaming and the mobile phone if needed.
Streaming is done by a Raspberry Pi Zero W, which serves as a wireless access point and streams the video to any device connected to the wireless network.
The mobile phone which displays the image is mounted with a 3d printed adapter to the wheelchair control unit.
Components
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Raspberry Pi Zero W
Main component for streaming video
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SainSmart Wide Angle Fish-Eye Camera Lenses for Raspberry Pi
Arduino Camera compatible wide angle camera (170° FOV)
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Plastic housings
One smaller housing for the raspberry and the camera, one bigger housing for the power distribution
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XLR Plug
To connect to the charging port of the wheelchair
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Car USB Port (eg. TurnRaise 12-24V 3.1A)
A 24V to USB converter in a small housing for car and motorcycle use. Can be anything which uses 24V input and provides USB output.
Install all updates by running the following two commands from a terminal:
sudo apt-get update; sudo apt-get dist-upgrade
Shut down, connect the camera. Start the raspberry again. In the Raspberry Setup panel enable the camera and enable SSH access to the raspberry. The sainsmart camera works as the official Pi camera, you can follow the instructions found here: https://www.raspberrypi.org/learning/addons-guide/picamera/
Unfortunately you are not done yet. We need a v4l driver for the raspi-cam, which is not enabled out of the box. First you should do a firmware update of your raspberry to get the latest firmware and kernel driver - run the following in a terminal: