DIY-THERMOCAM — OPEN-SOURCE THERMAL IMAGING CAMERA (FLIR LEPTON)
A real thermal camera you solder yourself, using a genuine FLIR Lepton sensor and open firmware.
by Max Ritter
WorkshopOpen-hardware
- difficulty
- ●●●●○
- time
- a weekend-plus
- license
- GPL-3.0
- repo
- repo ACTIVE1,206 stars
●●●●○ · a weekend-plus · GPL-3.0 · 1,206 stars · repo ACTIVE
WHAT YOU’LL NEED
- 3D printer + filament — printable parts — files are in the repo
- Electronic parts — full list with part numbers in the repo BOM
- Dev board / microcontroller — runs the project firmware
Partner
COMPAREE VERDICT
This is the real thing: a handheld thermal camera built around a genuine FLIR Lepton sensor, a Teensy 4.1, and a 2.4-inch touchscreen. The firmware is open, the documentation is exhaustive, and the result is a tool that shows heat leaks in walls, failing components on a board, or water pipes behind plaster. The build is advanced — expect forty-five soldering steps, surface-mount components, and careful cable routing. The biggest trap is sourcing: the official kit is gone, so you order the PCB from the Gerbers and buy parts yourself. The Lepton 3.5 sensor is still in stock at GroupGets, but at over a hundred dollars it dominates the cost. If a part goes out of stock or you pick the wrong Lepton variant, the build stalls. The project has been open for over a decade and the design is proven, but it is no longer actively developed. If you want a thermal camera and are comfortable with intermediate soldering, this is still the best-documented open-source option. If you expected a plug-and-play kit or your soldering skills stop at through-hole, look elsewhere.
IN THE REPO
NOT IN THE REPO
- —PCB Gerbers, enclosure STLs, full BOM, and firmware source are all in the repository.
- —The 45-step build guide at diy-thermocam.net walks through assembly, soldering, and calibration.
- —The ready-made kit is discontinued — you order the PCB yourself and source parts from the BOM.
- —The FLIR Lepton 3.5 sensor is still available from GroupGets as of July 2026, but the Lepton 2.5 is harder to find.
- —GPL-3.0 licence — you can build and modify freely, but derivatives must stay open.
- —Project is in maintenance mode — the last repository push was in 2023, though the core design is stable.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Partner · KickstarterHeyGears G1: 10M+ colors and transparent parts in one print, plus UV printing on flat objects. Figures, parts and labels — no painting.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the build guide at diy-thermocam.net (Start here — the guide is long but exhaustive, and you need to know which Lepton variant to buy before ordering parts.)
- 2.Check Lepton sensor availability(GroupGets still stocks the Lepton 3.5 as of July 2026, but availability changes — confirm before ordering the PCB.)
- 3.Order the PCB from the Gerbers in the repository (The ready-made kit is discontinued, so you fabricate the PCB yourself and source all other parts from the BOM.)
- 4.Source the full BOM (The BOM is in the repository — check every part number before buying, as some may be obsolete.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- The Lepton sensor is expensive and availability is inconsistent — if the 3.5 goes out of stock, the build stops. Check GroupGets or other suppliers before starting.
- The official kit is discontinued — you cannot buy a complete package anymore. You order the PCB, source every part yourself, and handle all assembly.
- The build guide assumes intermediate soldering skills — surface-mount components and careful cable routing are not optional.
- The project is in maintenance mode — the last repository update was in 2023. The design is stable, but do not expect new features or active support.
- The Lepton 2.5 is harder to find than the 3.5, and mixing sensor variants requires firmware changes — stick to the 3.5 unless you know what you are doing.
- Calibration is manual and matters — if you skip it, the temperature readings will be wrong. The guide walks through it, but it adds time.
Can I still buy a kit?
No — the ready-made kit is discontinued. You order the PCB from the Gerbers in the repository and source all parts yourself from the BOM.
Which FLIR Lepton sensor should I buy?
The Lepton 3.5 is still in stock at GroupGets as of July 2026 and is the recommended variant. The 2.5 is harder to find, and mixing variants requires firmware changes.
Is this easier than buying a commercial thermal camera?
No — commercial units are plug-and-play. This is a soldering project with 45 steps, and you handle sourcing, assembly, and calibration yourself. You build this because you want the experience or need the open firmware.
What resolution do I get?
The Lepton 3.5 is 160×120 pixels — far below a phone camera, but enough to see heat leaks, failing electronics, or water pipes behind walls.
Can I modify the firmware?
Yes — the firmware is GPL-3.0, so you can modify and redistribute it freely. Derivatives must stay open.
Is the project still maintained?
The repository is in maintenance mode — the last push was in 2023. The design is stable and the documentation is complete, but do not expect active development.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
The Lepton 3.5 sensor is still in stock at GroupGets as of this week, but at over a hundred dollars it dominates the budget. If you have built this or are planning to, which parts were hardest to source?
Max Ritter
Max Ritter built the DIY-Thermocam as a documented, reproducible thermal camera for makers. The project has been open source for over a decade, and the design pairs a genuine FLIR sensor with accessible microcontroller hardware.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM1mo agoedited
Practical notes from our verification: the project is in maintenance mode and the repository has not been updated since 2023, but the design is stable and the 45-step build guide at diy-thermocam.net is still complete. The ready-made kit is discontinued — you order the PCB from the Gerbers in the repo and source every part yourself. We confirmed the Lepton 3.5 sensor is still in stock at GroupGets as of July 2026, but availability is unpredictable and that single part is over a hundred dollars. This is an advanced build — intermediate soldering skills are not optional, and if you have never worked with surface-mount components or careful cable routing, expect a steep learning curve.