The Teledyne FLIR Lepton camera module is a powerful thermal imager no matter what level you pick, from the FS to the 3.5, or the new 3.1R. To make sure you’re taking advantage of all it has to offer, we wanted to go over our available Lepton boards, so you can pick the best one for your project.
There are four categories that we are going to focus on: breakout boards (BoBs), USB boards, wireless boards, and handheld cameras. At the bottom of the article is a small table laying out their price, dimensions, Lepton module compatibility, and more.
Breakout Boards:
Breakout boards are simple boards with no microcontroller. They handle the clock and power supplies to operate the Lepton; they will require something to connect to, and interface with, the Lepton - such as a RaspberryPi. Breakout boards include the PureThermal (PT) Breakout Board, the PT Mini BoB, the Lepton Breakout Board V2.0, and the OpenMV Lepton Adapter
PureThermal Breakout Board
The PureThermal Breakout Board was the first GroupGets BoB for the FLIR Lepton LWIR. It is an easy-to-interface evaluation board used to quickly evaluate the FLIR Lepton thermal camera modules. It is easy for quick prototyping, yet small and versatile enough for final projects.
FEATURES:
- Compatible with Lepton 2.x and 3.x
- Access to SPI and I2C camera module interfaces
- Provides 25-MHz reference clock
- Provides Power Regulation from 3.3-5V input
- 32-pin Molex camera socket for Lepton® Module
- PureModules compatible connector
- VSync and Enable Pins
PureThermal Micro Breakout Board
This little guy is the smallest Lepton board on the market, just slightly bigger than the Lepton that fits in it. It can be soldered onto a PCB using the castellated breakout or connect it via a 10-pin flat flexible cable (FFC) or flexible printed circuit (FPC) to communicate with the Lepton via I2C and VoSPI. This module takes care of the Lepton voltage supplies and 25MHz master clock, simplifying the integration process for designers.
FEATURES:
- Open-source reference code is on the GroupGets GitHub for getting started
- Compatible with all current 2.x, 3.x, and FS Lepton cores
- Super compact 12.2x14mm form-factor that can be embedded into other modules
- Castellated edges for integrating the module with a PCB
- 10-pin FPC/FFC connector
- KiCAD footprint available on GitHub for easy integration into new designs
Lepton Breakout Board V2.0
The FLIR Lepton® Thermal Camera Breakout Board is an easy-to-interface evaluation board to quickly connect the FLIR Lepton camera module to common platforms like RaspberryPi or custom hardware. It provides on-board power supplies, generated from 3 – 5.5V, and a master clock. Local power supplies, the master clock, and the power-up sequence components can all be bypassed using a jumper.
Fun fact: Our engineer says it has the most breakout pins out of the available BoBs. 
OpenMV Lepton Adapter Module
The FLIR® Lepton® Adapter Module allows your OpenMV Cam to interface with the FLIR Lepton 2.x and 3.x thermal Imaging sensors for thermal vision applications.
This is similar to the thermal vision of the OpenMV Cam H7. It can also control the Lepton with MicroPython and use OpenMV’s machine vision.
This fits perfectly on the OpenMV Cam H7 through the connector on the back of the adapter. More information can be found in this video by OpenMV.
USB Boards:
USB Boards are plug-and-play, and act as a UVC webcam. USB Boards include the PureThemal 3, the PT Mini USB, the PT Mini Pro JST-SR, and the PT Mini Pro No-Connector.
PureThermal 3
The PureThermal 3 is a hackable thermal webcam for the FLIR Lepton thermal camera cores. If you liked the PT2, then you’re bound to like the PT3, as it functions nearly the same, but comes with additional features. It is the most versatile of the listed USB boards, and our engineer Griffin says it is the most hackable.
FEATURES:
- STM32F412 ARM microprocessor: Execute on-board image processing without the need for an external system or SBC.
- USB UVC works on Windows, Linux, Mac, and sometimes Android
Open source reference firmware is on the GroupGets Github - 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
- PC15, PA0, PH1
- Breakout for SPI to communicate directly with the Lepton
- SPI bus is 3V with a 56 Ohm series resistor
- Partially MikroBUS™ compatible breakout pin configuration
- See the mikroBUS™ standard PDF.
- +5V is V_IN and +3.3V is +3V on PureThermal 3
PureThermal Mini USB
The PureThermal Mini USB is a hackable thermal USB webcam for the FLIR Lepton® thermal imaging camera core. It ships pre-configured to operate as a plug-and-play UVC 1.0 USB thermal webcam that will work with standard webcam and video apps on all major platforms.
The PT Mini USB runs on the same firmware as the PT3 and the PT Mini Pro JST-SR. It gives you the same functionality in a much smaller form. The only drawback is thermal performance, as this runs slightly warmer than the PT3 due to there being less space to dissipate heat.
FEATURES:
- Get Thermal video over USB right out of the box using freeware apps like VLC on Mac, Linux,
- Windows, or Android
- PTM 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
- Open source reference firmware is on the GroupGets Github
- Device Firmware Upgrade (DFU) the STM32 ARM MCU over USB
- Powered via USB Compatible with all current 2.x and 3.x Lepton cores
- Compact 19.5 x 15.32mm form-factor that can be embedded into other modules or inconspicuously housed as a standalone web, research, or security camera
PureThermal Mini Pro JST-SR
PureThermal Mini Pro JST is a hackable thermal webcam for the FLIR Lepton LWIR camera core. It has multiple connection options such as soldering straight to the board or with a custom cable using the JST-SR port.
PureThermal Mini Pro No Connector
Just like the other models, except without either a USB or a JST connector. The No Connector version of this board is perfect for anyone planning to solder it to a different circuit board or attach wires straight onto the PureThermal Mini.
Wireless boards:
t-Cam Mini rev4 (Onboard Antenna)
Designed by Dan Julio, the t-Cam rev 4 is a small board for wireless streaming with the Lepton thermal camera.
There is a cross-platform app with radiometry tools for wirelessly viewing thermal video. And, if you’re so inclined, the t-Cam can be hacked to transmit over radio
FEATURES:
- Hardware interface which allows the device to communicate directly with another microcontroller or
- SBC without having to use Wifi
- Now uses USB-C
- Comes with version 2.1 firmware
- The camera can operate in either Radiometric/TLinear (each pixel contains temperature data) or AGC modes (no temperature data in each pixel but better images).
- Simple json-based command set with communication of a TCP/IP Socket. Makes interfacing with the camera very simple from a custom application.
- AP or STA (client) Wifi modes (static or DHCP-served IPV4 address).
- Single image or streaming data modes.
- Control over sensor emissivity, gain and spotmeter location.
t-Cam Mini rev4 (external antenna)
The t-Cam Mini rev4 with the external antenna functions the same as the onboard antenna variant. This item is technically not available in our store at the moment, but if it is necessary for you to have the external antenna, please reach out to contact@groupgets.com so that we can make something work.
Drone Thermal
Lightweight and wireless, this is the answer to all your flying thermal imaging needs.
FEATURES:
- Supports all 160x120 pixels and 80x60 pixels Lepton thermal cores.
- 8 different Color Palettes for different requirements from surveillance to roof insulation.
- 2.4ghz WiFi module and the antenna onboard. (only for the firmware updates in the current firmware. The WiFi camera option will be added soon.)
- Weight is only 2.3gr (without the Lepton core)
- Dimensions: 20mm x 20mm x 10mm
- 3 wire simple output connection for FPV (V+, Ground, Video Out)
- Supply Voltage: 3.3V - 5V (3.6-4.2v 1S LiPo is ideal)
- Supply Current: 160mA continuous (350mA when FFC shutter closed)
- 25Hz PAL / 30Hz NTSC video signal output
- <9Hz Thermal image refresh rate (Maximum rate of Lepton)
- Automatic Temperature Gain Control
- Single-button interface for the modes and FFC
- 3.3v TTL Serial port for the debugging & future applications
Handheld cameras:
The PT OpenMV is the only one of these three that is both a Lepton board and a handheld camera. The others are handheld camera kits that are designed for Lepton boards, and therefore we wanted to include them in the list.
PureThermal OpenMV
The PureThermal OpenMV is the most feature-packed of the Lepton boards. It can access the OpenMV machine vision features, and can run a visible thermal overlay at the same time.
This board is fully loaded with features (I’ve listed a few here, but there are far more on its product page). The PureThermal OpenMV can be programmed like any OpenMV Cam in Python to make it do anything you like via the MicroPython API.
FEATURES:
- The STM32H743XI Arm® Cortex®-M7 SoC running at 480 MHz
- The OV5640 5MP (2592x1944) Color Camera Sensor
- The VL53L0X Laser Range Finder (can measure up to 2 meters)
- The WINC1500 WiFi Soc (FCC Certified)
- A 4.3” 800x480 IPS TFT capacitive touch LCD
- HDMI Display Output - can mirror the display or run without the onboard display
t-Cam gCore Portable Thermal Imaging Kit
This Lepton board also comes in the t-Cam gCore kit, which consists of the gCore and the t-Cam Mini rev4 (onboard antenna). The gCore, also created by Dan Julio, is a battery powered camera with a local touchscreen, local storage, and WiFi interface capabilities.
Our engineer says this is the most versatile of the handheld cameras - once you’re done with thermal imaging you can use it for other projects as well.
This kit is comparable to the PureThermal OpenMV mentioned above.
DIY-Thermocam V3 Kit
This DIY kit is aimed for anyone, whether you are an educator, student, hobbyist, maker, or anything else in between. Both the software and hardware are open-source, which allows you to customize the kit to your needs.
It runs on the Teensy microcontroller and has a cool software interface.
This kit is designed for the Lepton Breakout Board V2.0, and works with the Lepton 2.5 or 3.5. These items are not included in the kit, but there are links to them on the DIY Thermocam’s product page.
FEATURES:
- Fast ARM Cortex M7 processor (600MHz), based on the popular Teensy 4.1 microcontroller
- Frame rate of up to 9 FPS (US export compliance)
- 18 different color schemes including rainbow, ironblack, grayscale, hot & cold
- 3.2 inch LCD touch display with bright colors, wide angle and resistive touch
- Save thermal images with a resolution of 640x480 pixels on the device
- Save real-time videos and interval images with different time-lapse settings
- Internal storage over microSD card, accessible as a Mass Storage device on any PC via USB
- 2000 mAh lithium polymer battery for long operation time (4-6 hours)
- Open-source firmware written in Arduino compatible C/C++ code
- Regular firmware updates with new features, flashable over a cross-OS firmware updater
- Continuously growing ecosystem of software and open-source libraries to extend the device capabilities on the PC
In conclusion, there are many flavors of Lepton boards to fit even the most discerning tastes. Whether you’re tracking heat leaks in your house, or using a drone to assist in search and rescue, there is a Lepton and a Lepton board for you. We’ve included a table below that helps put some of the details in one place for you to compare.
