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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

FULL CAD BOM FIRMWARE DOCS

WorkshopOpen-hardware

Built withTeensy3D printing

difficulty
●●●●○
time
a weekend-plus
license
GPL-3.0
repo
repo ACTIVE1,224 stars

WHAT YOU’LL NEED

1
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COMPAREE VERDICT

This is the real thing: a handheld thermal camera built around a genuine FLIR Lepton sensor, a Teensy 4.1 and a 3.2-inch touchscreen. The firmware and desktop software are open, the documentation is thorough, and the result shows heat leaks in walls, failing components on a board, or water pipes behind plaster. The build is a 45-step guide of through-hole soldering, header strips, plug-in modules and careful wiring inside a tight enclosure. You order the PCB from the Gerbers and buy the parts from the partlist yourself; the Lepton sensor is the expensive part, and you can use a Lepton 3.5 or 3.1R (160×120) or the lower-resolution Lepton 2.5. The project has been open for years, the V3 design is proven, and the repository still gets software updates. If you want a thermal camera and are comfortable with a soldering iron, this is still one of the best-documented open-source options. If you expected a plug-and-play kit, look elsewhere.

GOOD TO KNOW

  • —PCB Gerbers, enclosure files, firmware and desktop software are in the repository; the full partlist is on diy-thermocam.net.
  • —The 45-step build guide at diy-thermocam.net walks through soldering, assembly and flashing the firmware.
  • —The ready-made kit is discontinued — you order the PCB yourself and source parts from the BOM.
  • —The partlist accepts a FLIR Lepton 3.5, 3.1R or 2.5; availability changes often (the GroupGets Lepton 3.5 listing was sold out when we checked), so confirm a source for the sensor before ordering anything else.
  • —GPL-3.0 licence — you can build and modify freely, but derivatives must stay open.
  • —The V3 hardware design is stable; the repository was last updated in December 2025, with software updates and merged community PRs earlier in 2025.

Parts to buy

8 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • Custom PCB (order from Gerbers)from the repo files
  • FLIR Lepton sensorFind
  • Lepton Breakout Board V2Find
  • Teensy 4.1Find
  • 3.2-inch TFT touch displayFind
  • LiPo batteryFind
  • Charging and step-up modulesFind
  • Rest of the partlistFind

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Can I build this?

PrintEnclosure parts (STLs in the repository)
BuyCustom PCB (order from Gerbers), FLIR Lepton sensor, Lepton Breakout Board V2, Teensy 4.1, 3.2-inch TFT touch display, LiPo battery, charging and step-up modules, and the rest of the partlist
ToolsSoldering iron, solder, cutting pliers, a sharp knife, screwdriver, tweezers, a multimeter, and a PC with Teensy Loader to flash the firmware
SkillsConfident through-hole soldering, basic electronics troubleshooting, and the patience to follow a long 45-step build guide
TimeA weekend-plus — the assembly guide alone is 45 steps, plus waiting for the PCB and parts and flashing the firmware.
CostMid-range budget — the FLIR Lepton sensor dominates the budget; the rest is a Teensy 4.1, a 3.2-inch touch display, the PCB, battery, modules and small parts from the partlist. The project does not publish a total.
SafetyLow-voltage DC only — no mains, no lasers, no chemical hazards. Standard electronics care.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

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Gallery

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 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. 2.Check Lepton sensor availability(Check current availability of the Lepton 3.5 or 3.1R (or the 2.5) with distributors before you order the PCB.)
  3. 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. 4.Source the full BOM (The partlist is on diy-thermocam.net (Documentation > Partlist); note that the PCB was designed for a TP4057 charger, which is out of stock, so the list substitutes a TP4056.)

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 you are comfortable with a soldering iron. It is all through-hole and module soldering, but the wiring inside the enclosure is tight and needs care.
  • The V3 hardware design is stable and is not getting frequent revisions. Updates in 2025 went mostly to the desktop software, so do not expect a new hardware version soon.
  • Pick the sensor deliberately: the build supports the Lepton 3.5 or 3.1R (160×120) and the Lepton 2.5 (80×60), so the 2.5 gives a much coarser image.

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 partlist accepts a FLIR Lepton 3.5 or 3.1R (both 160×120) or a Lepton 2.5 (80×60), all in the same Lepton Breakout Board V2. The 3.5 gives the higher resolution; check current availability with distributors before you order the other parts.

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 core V3 hardware design is stable, and the repository still receives updates: the desktop software got new features and merged community pull requests in 2025.

Community builds

No community builds yet — be the first, we feature the best ones.

Discussion1

FROM THE COMPAREE TEAM

A FLIR Lepton sensor, a 3.2-inch touch display and a 45-step guide built with ordinary hand tools. If you have built this or are planning to, which parts were hardest to source?

CompareeTEAM2mo agoedited

Practical notes from our verification: the repository is still maintained — it was last pushed in December 2025, with software commits and merged pull requests during 2025 — and it holds the open-source firmware, the desktop software, the enclosure files and the printed circuit board. The full build guide on diy-thermocam.net runs to 45 steps, from soldering through firmware flashing (step 42) to the enclosure (steps 43 and 44), and the parts list is on the same site. The build is more approachable than it looks: the guide's tool list is a soldering iron, solder, cutting pliers, a sharp knife, a screwdriver and tweezers, and the soldering is header strips and through-hole parts rather than fine surface-mount work, with a multimeter used along the way. The single part that dominates the budget and your sourcing effort is the FLIR Lepton thermal sensor, so check its availability before you order anything else. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.

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.

GitHub Web

Star the project on GitHub

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.
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