PureThermal 2 - FLIR Lepton Smart I/O Board

The PureThermal 2 Smart I/O Board is a hackable thermal USB webcam breakout for the FLIR Lepton® thermal imaging camera core. Each PureThermal 2 ships pre-configured to operate as a plug-and-play UVC 1.0 USB thermal webcam that will work with a standard webcam and video apps on all major platforms. For developers, its reference firmware, viewer software, and hardware schematic are all open source!

Each PureThermal 2 is equipped with the reliable STM32F412 ARM microprocessor capable of processing images without any external system inputs. With a Lepton inserted into the PureThermal 2 you will be able to achieve 9Hz color video over USB using the USB UVC class. If USB isn't necessarily your desired medium, this board has also been fitted with 0.1" pins to interface over UART or I2C.

It's easy to get started with the PureThermal 2 with the open source software application, GetThermal. The PureThermal 2 and GetThermal both support the radiometric mode of Lepton 2.5 & 3.5 and can view Lepton data on x86 Linux and macOS platforms or even on a Raspberry Pi.

Note: The PureThermal 2 does NOT include a FLIR Lepton imaging module and will need to be purchased separately or in the Dev Kit. The Lepton module is extremely sensitive to electrostatic discharge (ESD). When inserting it into the breakout board be sure to use proper personal grounding, such as a grounding wrist strap, to prevent damage the module.

  • Get Thermal video over USB right out of the box using freeware apps like VLC on Mac, Linux, Windows, or Android
  • PT2 can do 9 Hz color video over usb using the USB UVC class
  • STM32F412 ARM microprocessor. Execute on-board image processing without the need for an external system
  • Through-holes for GPIO and peripheral breakouts to easily attach other devices
  • Device Firmware Upgrade (DFU) the STM32 ARM MCU over USB
  • Debug via JTAG through a 6-Pin plug-of-Nails port using a Tag-Connect TC2030-IDC-NL, an ARM20-CTX, & ST-Link V/2.
  • Powered via USB
  • UART, I2C, and GPIO Expansion via standard 0.1” holes
  • Compatible with all current 2.x and 3.x Lepton cores
  • Dimensions: 30mm x 18mm

PureThermal 2 - FLIR Lepton Smart I/O Board Product Help and Resources

FLIR Lepton Hookup Guide

March 26, 2015

See the invisible world of infrared radiation using the FLIR Dev Kit and Raspberry Pi.

GetThemal App installation videos

Core Skill: Programming

If a board needs code or communicates somehow, you're going to need to know how to program or interface with it. The programming skill is all about communication and code.

3 Programming

Skill Level: Competent - The toolchain for programming is a bit more complex and will examples may not be explicitly provided for you. You will be required to have a fundamental knowledge of programming and be required to provide your own code. You may need to modify existing libraries or code to work with your specific hardware. Sensor and hardware interfaces will be SPI or I2C.
See all skill levels

Core Skill: Electrical Prototyping

If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.

2 Electrical Prototyping

Skill Level: Rookie - You may be required to know a bit more about the component, such as orientation, or how to hook it up, in addition to power requirements. You will need to understand polarized components.
See all skill levels


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • dpaton / about 6 years ago / 2

    Does this support the Lepton 3.5 (160x120) or only the older units (80x60)?

  • Member #1574466 / about 4 years ago / 1

    Is it going to work with First gen of lepton from cat s60 smartphone And does it suport flir one App on android?

    • CF / about 4 years ago * / 1

      This will work with a computer, no idea if they work with a smartphone or any phone apps. You'd need to try that on your own and see.

  • Member #1559516 / about 4 years ago / 1

    How do I get the UART to work ??

    • santaimpersonator / about 4 years ago / 1

      For the simplest setup, users should use the USB interface.

      Otherwise, you will need check out the product page for more technical resources. Unfortunately, using only the serial pins is probably outside the scope of our support team and you will probably need to reach out to the manufacturer for assistance with that.

  • What's the order limit?

Customer Reviews

4.5 out of 5

Based on 6 ratings:

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1 of 1 found this helpful:


I had been working with the Lepton for a little bit. I'm using this with a robot - the USB interface is much more robust and easier to use and move between CPU classes. I have had issues when running it through a USB3 hub, where the image will freeze sometimes, but otherwise it does the job.

Review PureThermal 2 FLIR

I purchased this module a few weeks ago and it is the easiest way to connect your project to a lepton sensor. Highly recommended.

user friendly, easy to install

Extremely overpriced / basically useless - bad combo

I got this hoping to be able to use a salvaged Lepton sensor from a broken FLIR one camera. First of all, the board is smaller than a postage stamp and the ends are cut poorly with long, jagged strings of the previous board still attached. Labeling is not very legible. Uses old microUSB connection instead of USB-C. When using as webcam functionality, does not take RJPEGs, only regular JPEGs so using the images in FLIR tools is not an option since there is no embedded temp data. And the app they do provide as a GitHub download is really complicated to install, and only works on Mac / Linux. I was hoping to make a stand-alone camera using a Raspberry Pi, but that doesn't appear to be an option any more. Basically, I am way better off just buying a complete FLIR camera and using the app. I definitely wasted the hundred bucks on this tiny useless thing.

Completed a long-ignored project

I've had a Lepton 2.5 kicking around here with an older board that connected to the Raspberry Pi, and had been intending to 3D print a camera frame, add a rechargeable battery, and use a Pi screen to view the Lepton output. Think I've been contemplating that for about 2 years? A few weeks ago I bought this board, plugged my Lepton into it, and connected it to my laptop. BAM. Project completed. Well, completed enough to not keep thinking that someday I'll get around to building my own. So worth it. Thanks!