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The goal of this project is to create a relatively inexpensive camera platform that can be mounted on a drone, transmit a 1080p video feed, and remotely control pan, tilt, and optical zoom. An interface to this will make it simple to develop computer vision applications that require camera movements.
Here's the current layout of the system.
For video I'm using the Walksnail Avatar HD FPV video system. It's designed for low-latency FPV quadcopters, and can transmit a 1080p 60fps video feed back to a base station. The link has favorable qualities for this application, with the manufacturer claiming a range of around 2.5 miles, but some online have been able to achieve greater ranges than that.
The only issue with this system in this case is that the camera features an extremely wide-angle lens. Such a lens is optimal for flying an FPV drone, but I wanted a more flexible camera that could zoom in/out and still have detail. Ideally the camera could be replaced, but the link between the camera sensor and the video transmitter appears to be a proprietary protocol on some sort of coaxial cable, which I don't have the expertise to reverse-engineer. However, the camera lens is easily removed, and the micro camera version has a 1/2.7" sensor.
The solution was to attach the sensor to a larger lens which would allow for remote zoom and focus. I settled on one of these Raspberry Pi Pan/Tilt/Zoom camera lenses, which are designed for a 1/2.7" sensor, and have servo motors to control zoom and focus from a Raspberry Pi. I used a 3D printed mount to align the sensor and lens in a robust fashion.
The Walksnail Avatar video receiver outputs an HDMI signal, which I'm converting into a webcam feed using an Elgato Cam Link. This allows any computer vision application to easily get a video feed and treat it as a normal webcam.
The electronics setup is currently overcomplicated for what it does, and I'm working on developing a simpler system that reduces the amount of communication required between devices. More to come in the future.
To control the camera I'm using an ExpressLRS controller and receiver.