Easiest Way To Display Video?

[George TechandTopics]

Whats the easiest way to display video on a mini lcd screen? Would it just be to use a breakout board, like purethermal or flir? Or do I need another machine between them, like an ESP32 or something? If I need another machine, which is easier to use, or has more support, with lepton - esp32, pi zero, ardurino?

[George TechandTopics]

Well, my plan for now is to just ise the SPI to send video to a small LCD screen that supports SPI. I'm not sure how vsync works. I'm hoping the breakout board handles all the vsync part and that any lcd will work with it. 

[Dan Julio]

You need some intelligence between the Lepton and the LCD display.  Code running on this device needs to read data from the Lepton via its VoSPI interface, convert it into an image (RGB data) and then push it to the LCD display via another SPI interface.  Conversion of the radiometric data from the Lepton to a RGB image generally requires scaling it into a set of 8-bit values and then using those to index a false-color palette lookup to get RGB values for display.  The VSYNC signal on the breakout board must be enabled by sending a command to the Lepton via its I2C CCI interface.  VSYNC is used to notify an external device there is a frame available to read.  Reading the VoSPI interface is not trivial although there is a lot of code out there on the internet showing how.  Minimum requirements are probably a 32-bit processor with > 32 kB of RAM.  An Arduino won't cut it.

People have used boards like the Raspberry Pi with both the raw Lepton breakout board and the USB UVC capable PureThermal boards but the Pi is a bit heavy (linux) for a simple display.

What might interest you is Damien Walsh's build: https://damow.net/building-a-thermal-camera/.  He used an ESP32.

And if you want to see various approaches I took over the years: https://github.com/danjulio/lepton.  I made a camera with a LCD display called tCam too (https://github.com/danjulio/tCam/tree/main/tCam)

Interestingly the PureThermal firmware (at least the source) seems to have some code related to displaying on an LCD but I'm not sure that's enabled and I've never seen one directly connected to a LCD.  You might check out the firmware repository though: https://github.com/groupgets/purethermal1-firmware

Finally, search github.  There are a lot of projects (of varying capability and completeness...).

Good luck!  Thermal imaging is very cool.

[George TechandTopics]

Thanks for the clarification! That tutorial is exactly what I needed.

[George TechandTopics]

Is there by chance a more detailed tutorial?

I'm having a hard time setting up the lepton to work with a little lcd. For whatever reason, the tutorials I do find don't seem to work for me. I always have some error around the setting up the two SPI channels (on two busses) before ever getting to the lepton part. 

[Dan Julio]

These are definitely not detailed tutorials but a long time ago I did a series of Teensy 3.2 Arduino sketches for a simple camera I built with an LCD module and a lepton breakout board.  Perhaps some of that code might inspire you.  Probably you'd start by looking at lep_test10.  If you didn't want to duplicate all the hardware you could strip out the power management code.

https://github.com/danjulio/lepton/tree/master/teensy3

[George TechandTopics]

Thanks. I'll give that a try, but I think I'm just too dumb to get this working.