Hot Camera Contest

A contest for open drivers for the ESP32 and Raspberry Pi Zero W for the FLIR Lepton in Radiometric mode

Wednesday, July 18, 2018 12:00 am GMT - Monday, August 20, 2018 12:00 am GMT Local time zone:
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I have tried to port the existing Radiometric Lepton 2.5 drivers/software to two battery-powerable platforms (the Raspberry Pi Zero W and the ESP32 Arduino implementation), but it seems to require more brainpower than a sleep deprived new father can muster.  And so I present to you, the informal Battery-powered Radiometric Lepton Contest!


The FLIR Lepton is a thermal camera made accessible to the maker community by the wonderful folks at GroupGets, who (in addition to making the Lepton available in small quantities), also produce a breakout board for the lepton, as well as a board called the Purethermal 2 that exposes the Lepton as a USB device. 

The Need

While there's been a great deal of work in creating open source drivers for the Lepton (such as pylepton and GetThermal for the Raspberry Pi, and this Arduino Lepton driver), there's currently a limitation in capabilities.  To the best of my knowledge, there are not working, easily-replicable demonstrations (including code) to use the Lepton in radiometric mode (that's where each pixel has an associated temperature value, not just a relative value) for platforms that can be battery powered and have a low barrier to entry-- specifically here, the Raspberry Pi Zero W, and the ESP32 Arduino implementation.  

The purpose of this contest is to help improve this situation by asking folks to publish open source drivers and instructions to drive the Lepton 2.5 in radiometric mode for these platforms, with battery power in mind. 


Two $125 prizes (in the form of Sparkfun credit) are available: one for the Raspberry Pi Zero W platform, and one for the ESP32 Arduino platform.


Create a project with all the relevant materials, and add a link to it in the comments to this contest!


The deliverables:

  1. An open source driver and example code for running the FLIR Lepton 2.5 in radiometric mode, on either the Raspberry Pi Zero W, or the ESP32 (under the Arduino IDE). 
  2. The drivers and software must be published using an open, permissive license (e.g. BSD)
  3. Hardware: The drivers must interface with the commodity, easily-available breakout board.  For the Raspberry Pi Zero W, you may alternately choose to use the PureThermal 2 (which may simplify keeping the camera in sync).  The drivers must interface with the radiometric Lepton 2.5 .  Also being able to interface to the brand new Lepton 3.5 in addition to the 2.5 is a bonus, but not required. 
  4. Software (Pi Zero W): You must provide the source of a console program that runs on Raspbian that outputs space-delimited temperature values, one per pixel, in plain text (e.g. 24.5 20.2 18.8, ...), with successive frames delimited by a carriage return (\n).  The program should be able to be piped such that the values can be saved to a text file, or called/read in by another program.  
  5. Software (ESP32 Arduino): You must provide the source of a program that reads frames from the Lepton, and stores them in an 80x60 array.  The values can either be floats (e.g. 24.5) or 8-bit uint8_t's (for space) that are easily converted to raw temperature values with the supplied code.  The software should work on the standard ESP-WROOM-32 modules (with a minimum of pin requirements). 
  6. Battery power: Either through simple hardware or software, you must demonstrate being able to put the FLIR Lepton into low power (or zero power) mode, and wake it (and repeated cycles of this), so that both systems can run on batteries, and only power the FLIR when required.   Use a current meter to demonstrate that this is working and provide measures of the power draw.  Clarification: the low-power mode, whether implemented...
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  • About one week (two weekends) remain

    peter jansen08/11/2018 at 03:47 0 comments

    Hi all,

    A quick note -- about one week (and two weekends) remain for the Hot Camera Contest.  There are very few submissions at this point (and, to the best of my knowledge, none that are complete), so if you're able to meet the criteria, the chances are currently high for you to walk away as the winner. 

    Thanks to all contributors, and best wishes. 

  • Merging prizes, helpful notes

    peter jansen07/25/2018 at 04:29 0 comments

    Hi all,

    We have about four weeks to go in the Hot Camera contest!  Here are a few quick announcements, notes, and helpful resources: 

    1. In the event of only one winner, the prizes will merge

    In light of the very different platforms (ESP32 Arduino vs Raspberry Pi Zero W) and very different available open resources for these platforms, I'd like to make a favourable rule modification:  If, at the end of the contest, one platform doesn't receive a complete submission, then the total of both prizes ($250 in Sparkfun credit) will go to the winner of the platform that does submit a complete and winning entry.  That means (for example) that if there are no complete ESP32 Arduino submissions, but there is a complete/winning Raspberry Pi Zero W submission, then the Raspberry Pi Zero W winner will receive $250 in Sparkfun credit instead of $125. 

    2. FLIR Lepton Google Group

    A helpful resource for those developing software and drivers interfacing to the Lepton:!forum/flir-lepton

    3. Possible low-hanging fruit: The PureThermal 2

    The new PureThermal 2 board is advertised as having open firmware that can be updated over USB, and that already supports the Lepton 2.5 (and 3.5) in radiometric mode.  It also keeps track of all the sensitive timing of the sensor, making it significantly easier to interface with other platforms (like the Raspberry Pi Zero).   My sense of things is that getting this board to work with the Pi Zero in Radiometric mode (they already seem to work with the larger Raspberry Pi's), then making modifications to the firmware (and possibly simple modifications to the board itself) to support a low-power mode, might be one of the easiest paths to success, and most broadly useful for the community of users. 

    thanks for reading and contributing!

View all 2 contest logs

Enjoy this contest?



disasterarchy wrote 08/19/2018 at 07:35 point

My entry is here

I worked on the RPi Zero platform and tested against Lepton 2.5 and 3.5.  Checkout my current results in the project update.

  Are you sure? yes | no

Dan Julio wrote 08/16/2018 at 16:21 point

I can't enter the contest but I have some code that might be helpful for people using the Lepton 3.5 at  There's a port of the FLIR CCI library to arduino/Teensy3 (that should be easily ported to ESP32).  This allows control of the camera via the I2C interface.  There is also a port of Damien Walsh's leptonic program that allows streaming of images to a web browser using the VSYNC output and a user-space interrupt handler to synchronize the video stream.  It should be fairly easy to port to the Lepton 2/2.5 (no need for handling multiple segments).

  Are you sure? yes | no

pesh wrote 07/25/2018 at 19:37 point

Wouldn't putting the lepton to sleep effectively require a restabilization period post flat field correction event, where the incoming data is "jumpy"? I only mention this because radiometric data usually requires stability in data prior to actual data collection event. Putting the lepton to sleep too frequently might run counter to the need for radiometry.

  Are you sure? yes | no

tz wrote 07/18/2018 at 22:50 point

You mention BSD.

IS GPLv3 acceptable?

  Are you sure? yes | no

peter jansen wrote 07/18/2018 at 23:43 point

Hi TZ, the rules require an open, permissive license ( ) -- usually this means MIT, BSD, or Apache 2.0

  Are you sure? yes | no

Alejandro wrote 07/18/2018 at 19:56 point

Hi! nice contest!

I have my battery powered FLIR portable camera that I made with a lepton module and a Rpi3, can I compete?


  Are you sure? yes | no

peter jansen wrote 07/18/2018 at 23:47 point

Hi Alejandro, it sounds like a great project!  This contest isn't for a complete thermal camera, only for open drivers and documentation for two specific platforms (the Pi Zero W and the ESP32 Arduino platform) -- so if you (for example) have ported the drivers specifically to the Raspberry Pi Zero W platform, and meet the other requirements and deliverables listed above, then those would be what you submit.  

  Are you sure? yes | no

Pure Engineering wrote 07/16/2018 at 20:04 point

So does the stm32 count as a battery powered microcontroller, I would think so. 

All the source code is posed here.   you can output uart as well as usb, and embedded your application with the stm32 as well. 

  Are you sure? yes | no

Pure Engineering wrote 07/16/2018 at 20:07 point

also note, the pure thermal 1 has a built in li-ion charger via the USB port. and can power the whole camera with any single cell li-ion battery.  there is an On/off button as well to turn it on and off.

  Are you sure? yes | no

peter jansen wrote 07/18/2018 at 07:54 point

Thanks for this question -- I've clarified in the rules that the low-power mode must be software controlled, whether implemented as software only or a combination of hardware and software.

  Are you sure? yes | no

peter jansen wrote 07/18/2018 at 07:55 point

Thanks for this question: the rules specify two specific platforms for this contest, the ESP32 using the Arduino platform, and the Raspberry Pi Zero W.

  Are you sure? yes | no

Matthew Navarro wrote 07/16/2018 at 19:08 point

Cool contest, looking forward to see what people come up with! (edited)

  Are you sure? yes | no

peter jansen wrote 07/18/2018 at 07:56 point

You are awesome, thanks!

  Are you sure? yes | no

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