The PureThermal 3: The Perfect Pink Lepton Board for Any Project

The PureThermal 3: The Perfect Pink Lepton Board for Any Project

If you’ve been around GroupGets for a while, you’ve probably heard of the PureThermal 3, the successor of the PureThermal 2. If you’re new, though, please let me introduce you to what we consider the perfect Lepton board for any of your thermal projects. 


The PureThermal 3 FLIR Lepton Smart I/O Module is a hackable thermal webcam module for the Teledyne FLIR Lepton Longwave Infrared (LWIR) camera core. 



  • STM32F412 ARM microprocessor: Execute on-board image processing without the need for a external system or SBC
  • USB UVC works on Windows, Linux, Mac, and sometimes Android
  • Open source reference firmware is on the GroupGets Github
  • Open source reference image viewer software for Linux and macOS
  • USB-C connector
  • Flash custom firmware with USB DFU
  • Castellated edge with full JTAG breakout for rapid flashing
  • Better buttons for Boot and Reset
  • 3x STM32F412CG GPIO pins
  • Breakout for SPI to communicate directly with the Lepton
    • SPI bus is 3V with a 56 Ohm series resistor



This open source, hackable thermal webcam module is preconfigured to operate as a plug-and-play UVC 1.0 USB thermal webcam that will work with standard webcam apps such as VLC Media Player on PC, Linux, Mac, and Android. With a Lepton inserted into the PureThermal 3 you will be able to achieve 9Hz color video over USB using the USB UVC class.

 You can also enter bootloader - Device Firmware Upgrade (DFU) - mode if you're not compiling from source. You can find instructions on how to do so here. However our head engineer at GroupGets, Griffin Covert, designed the PureThermal 3 with a JTAG breakout along the top castellated edge. This, in combination with a custom jig (or a Tag-Connect EC-10 cable) allows for more rapid flashing at the fab compared to DFU over USB.



The PureThermal 3 is a jack-of-all-trades when it comes to thermal imaging - letting you experiment with including motion sensing, moisture detection, night vision, inspection of electronics, and even the recognition of gestures. 

We’ve taken a look through previous PureThermal 3 sales and the ways our customers make use of their PureThermal 3s: 

  • Hobby projects, such as a DIY thermal camera
  • Thermal image overlay onto regular/ IR camera, for AI image recognition with possible healthcare applications
  • Monitoring heat generation and dissipation of manufactured circuits
  • A number of Universities use it for academic purposes
  • Integration in autonomous robots
  • A fire detection and control system 

There are more than a few FLIR Lepton boards on the market, so why pick this one? Well, I decided to ask our head engineer, Griffin Covert that exact question, and he told me “If you’re looking for a hacker-friendly STM32F4 based FLIR Lepton development board that’s also suitable for end use, PT3 is for you. Integrate your peripherals with easy breakout access to the MCU’s GPIO and the Lepton’s I2C and VoCPI interfaces. The applications are limited only by your imagination… and the laws of physics. But don’t worry, we won’t tell the universe if you break them.” 

If that isn’t enough to convince you, I’ll let you know that out of the PureThermal family, the PT Mini, and the PT Mini Pro JST-SR do NOT have JTAG access, which is great for testing custom firmware that needs multiple iterations or for flashing a large batch. It also allows for JTAG debugging which can give deeper insights to what's going on as the code runs. 

 No matter what you pick, GroupGets is here to help, which is why we put together a fun bundle for you: the Teledyne FLIR Lepton 3.1R and the PureThermal 3. These two can be bought separately in the store, or you can get it at a steep discount by joining the  - hurry, it ends soon!


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