tCam - An open-source thermal imaging camera - Page 1
Forum section: electronics / projects

author: globoy
author_rank: Frequent Contributor
timestamp: November 06, 2022, 10:23:49 pm
content: [tl;dr] I open sourced a design for a thermal imaging camera. Pics & links below the long explanation... Thanks to Group Gets you can build one if you are interested. Or you could use my code in your own project.For some years I've been playing with the Flir Lepton 3.5 thermal imaging module (when I started the Lepton 3.5 was $300 and now it's $150). At the time I started, the Lepton was really the only affordable module. I made a bunch of cameras with it starting with the Teensy 3.2 to the Pi, the Beaglebone family and finally with the ESP32. All of my travails were documented in a hackaday.io project and the source code pushed to github.The camera I spent the most effort on and am most proud of is tCam which is based on two boards I designed (gCore and tCam-Mini), a bunch of code and 3D printed or laser cut case. It has a 480x320 pixel capacitive touch display with a LVGL-based GUI, the ability to store images and videos to a Micro-SD card and a WiFi interface that lets it talk to applications running on Desktop Computers and Smart Phones (iOS currently, Android in development). There's also a python driver and people have written R and Matlab interfaces as well. One of my biggest interests came from the idea of making radiometric data available for various applications outside the traditional thermal imaging market (since it's already so well served) so the main data format for tCam (and tCam-Mini) file output contains the raw radiometric and telemetry data from the lepton. Pretty pictures are made from that. Unfortunately due to licensing issues I don't yet have the ability to write out Flir compatible image files from any of my apps.Before I finished tCam, I finished a simpler version called tCam-Mini that only had a WiFi interface at first. I published its design and Group Gets offered to build them and ran some campaigns and carries it in their store. It complements their distribution of Leptons. I ended up making a little royalty money which was nice.Originally I wanted one ESP32 to serve as the core of a tCam with display and storage but it wasn't up to the task of reliably dealing with the Lepton VoSPI interface, streaming via WiFi or to a Micro-SD card and updating the LCD at the same time at the Lepton's maximum 8.7 FPS so I split the problem into two parts. tCam-Mini got a hardware interface consisting of a serial port for commands and SPI slave to output the camera data and I designed another board, a more generic ESP32 Dev board for portable graphics gadgets, called gCore and rewrote the tCam firmware to run on it and talk to a tCam-Mini as a high-level thermal imaging camera module (tCam firmware doesn't have to deal with the low-level bandwidth intensive VoSPI interface). Splitting the effort between two boards works really well and enables the necessary performance.Most of this work occurred during the pandemic which was great for time, not so great for parts availability.With the parts shortage easing, Group Gets offered to run a campaign for gCore which means people could build a tCam if they wanted so I have published its design and code to github and am publicizing it a little in case anyone is interested. I realize that there's a commercial element here and I hope I'm not violating the rules of this board by posting in this forum. Not my intent. I'll certainly delete the post if it's in the wrong place but mainly I'm very proud of this project and wanted to share it. I finally got the camera I wanted and I learned a lot.Github repository:https://github.com/danjulio/tCamhackaday.io project:https://hackaday.io/project/159615-lepton-35-thermal-imaging-cameraOriginal github repository (with my older lepton projects):https://github.com/danjulio/lepton

author: moffy
author_rank: Super Contributor
timestamp: November 06, 2022, 11:21:56 pm
content: Thank you for sharing this, it looks like an enormous amount of effort. With the use of thermal cameras in fault finding it could be usefull to many. I will certainly have a good look at your Github repository.

author: globoy
author_rank: Frequent Contributor
timestamp: November 07, 2022, 12:38:31 am
content: Thank you. As a EE I have definitely used it and other cameras to look at PCBAs to see how hot something is getting or where something like a short is. And for fun I ran a tCam-Mini off of solar power with a detection algorithm and recorded various wildlife that traversed our property. I was hoping to see a bear or mountain lion but never caught one of those. Plenty of dogs, deer and foxes though. Some people fly the tCam-Mini on drones and do stuff like look for failing cells in big solar arrays (they don't get as hot). I've worked with research scientists who image burning forests to create computer models of how the energy is distributed and then released to help forestry planning and fighting fires. And I spoke to a guy who trained a ML model to spot elephants who sometimes come too close to villages in India. A thermal camera was chosen because it works in all light and many weather conditions. Thermal imaging is really neat.