This 3D-Printed Roof Mounting System Turns a Raspberry Pi Into an Aurora-Capturing Flight Tracker
A maker's first attempt showed moisture and thermal issues, which led to a redesign to move the Raspberry Pi indoors.
Pseudonymous maker "Do_Hard_Things," hereafter referred to simply as "Things," has been working on roof-mounting a Raspberry Pi-powered sensor system in a 3D-printed carrier — and has advice on what you'll need to think about if you're doing the same.
"I made a rooftop mounting system for some different [Raspberry] Pi-based sensors," the maker explains of the project, which sees two sensor packages — one for radio and one for visible light — mounted to the apex of a wooden roof. "Had to solve some interesting thermal and moisture issues."
The project is driven by a Raspberry Pi 4 Model B single-board computer, with the optional Power-over-Ethernet (PoE) HAT to make delivering electricity simpler while the board is externally mounted. To this, there's a software-defined radio (SDR) dongle that serves to pick up Automatic Dependent Surveillance-Broadcast (ADS-B) signals to track passing aircraft and a Raspberry Pi HQ Camera Module connected to an extreme fish-eye lens.
That lens, on an M12 mount, points directly upwards — capturing a view of as much of the sky as possible. To make that work took a little thinking: the electronics are housed in a length of ABS tubing, cleverly arranged on a 3D-printed shuttle that can slide directly into the tube. An off-the-shelf end-cap is then modified by drilling it out and adding an acrylic dome — allowing the camera to see out but keeping the weather from making its presence felt within.
At the base of the tube, which is mounted to an antenna bracket, the system's cables appear. "[I] mounted a cable gland in the bottom of a screw-in plug in hopes of keeping it watertight," Things explains. "It didn't work very well, as I tried to get two wires through it at the same time."
Another issue was temperature: despite being painted a lighter color than its stock black, the tube proved effective at capturing the sunlight — hitting over 60°C (140°F) on sunny days. Coupled with moisture gathering inside the tube, which turned out to be less well-sealed than expected, Things set about redesigning things for improved ventilation — and to separate the camera sensor from the single-board computer.
"Thanks to Tinkercad, I made a housing exclusively for the [Raspberry Pi] HQ [Camera Module], adapted to a[n] HDMI cable (Arducam HDMI-CSI adapters), so I could put the [Raspberry] Pi inside the house with good air movement around it." A 3D-printed weatherproof cable gland and a freshly-printed tube — housing some silica gel to absorb any moisture that may have snuck in during assembly — completed the build, which delivered some impressive shots of the Northern Lights.
The full write-up is available in Thing's Imgur post.
Freelance journalist, technical author, hacker, tinkerer, erstwhile sysadmin. For hire: freelance@halfacree.co.uk.