Leptonic

A web GUI and several utilities for working with FLIR® Lepton® 3 LWIR camera modules.

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Leptonic can:

• Stream a live view from a Lepton® 3 camera to any modern web browser.
• Be integrated into your own C projects to work with Lepton® 3 cameras.

Currently supported features:

• VoSPI interface (RAW14 format only, code could be adapted to support RGB888)
• Telemetry (header-location only)
• I2C CCI (partial)

Currently supported hardware:

• FLIR® Lepton® 3 (160x120 resolution) [link]

The code is written in such a way that adapting it to work with the original 80x60 camera modules should be fairly straightforward. Unfortunately I do not currently own one to develop with, so haven't embarked upon this endeavor just yet.

Pull requests are of course welcomed!

Dependencies

Recommended platform is Raspberry Pi with Raspbian. That's currently the only hardware I've tested this out on, but others should work fine too.

Generally:

• Linux, SPI support (via spidev)
• ØMQ/ZeroMQ (libzmq3-dev) for the camera interface/frontend IPC [guide]
• I2C support enabled for CCI interface use.
• NodeJS for the frontend stuff (yarn/npm to install dependencies)

Specifically:

• spidev's bufsiz module parameter must be set to a value large enough to receive an entire Lepton® 3 VoSPI segment (10004 bytes with telemetry enabled, 9840 without). By default this isn't the case, so please do check before running the code.

Building

• Check out the codebase.
• Make sure you've satisfied the dependencies, namely libzmq3-dev
• Run make to build the Leptonic IPC server. Run make examples to build the examples in the examples directory.
• Install the NodeJS dependencies with yarn install or npm install in the frontend subdirectory.

Running

• Start the IPC server with ./bin/leptonic /dev/spidev0.0 (switching out the name of your spidev device file as appropriate). You may optionally also supply a socket address to bind to as a second argument (I.e. tcp://127.0.0.1:5555).
• Start the frontend app with yarn start or npm start from the frontend subdirectory. You may optionally also supply a socket address to connect to as a second argument (I.e. tcp://127.0.0.1:5555).
• The Web UI should now be running on port 3000.

Performance

The camera communication process is extremely time-sensitive. There are strict parameters pertaining to how quickly frames and segments must be clocked out of the camera's SPI interface. Any slowdowns/scheduling caused by a master based on a multitasking OS such as Linux can cause the code to lose VoSPI synchronisation. While my code does reacquire synchronisation immediately, this does cause a visible amount of frame-drop in the output.

Empirically, I've found that the Raspberry Pi 3 Model B struggles a little running both the camera interface and the frontend together. You might find it best to run the frontend server on a separate machine and have the ØMQ traffic go over the network.