No clue- Sounds like you just changing values without understanding what they supposed to be doing. This software you talk about and the arbitrary values. If you need a refresher on how the GPIO pins are oriented, visit our Raspberry Pi GPIO tutorial. (They recommend 25Mhz) Did you provide that? Connect the FLIR breakout to the Raspberry Pi GPIO according to the diagram below. I suspect they did not include a crystal in the LEPTON to keep the size down and embedded devices usually have access to some kind of constant clock any way. Now we know Raspbian is not very great at generating consistent clock rates consistently so you may be experiencing problems with this - The same way may other FLIR'ers are experiencing. I assume you got it hooked up to SPI correctly but one of the problems seems to be the Input Clock rate. Raspberry Pi 4 with Ubuntu server 18.04.01 for RaspberryPi installed with Spinnaker SDK consisting of Spinnaker 2.3.0.77 Ubuntu 18.04 for arm64 and Spinnaker python for python 3.7 The camera is a FLIR Blackfly S-U3-244S8M-C (24MP, 4/3 Sensor, USB3.0) and connected to one of the USB3 ports. I removed and connected the camera, and still no image is shown. I bought it with the PureThermal 2 - FLIR Lepton Smart I/O Board, and therein is a problem when connected to my Ubuntu Linux as a USB camera, that board eventually locks up badly, and has to be disconnected from power to bring it back to life. So looking around really I noticed the protocol used on the Lepton is VoSPI (Video over SPI) Frankly never heard of that before but its plausible because the frame size is 80 x 60, which is not a crazy amount of data with some kind of AGC applied format which is selectable (Did you select the correct one?) I am having problems with connecting FLIR Lepton to Raspberry PI 2. FLIR Lepton Official Product Link Wiring Guide For installation on Raspberry Pi, NanoPi, Beaglebone, Thinker Board, Snapdragon Board, Lemon Pi, LattePanda, Banana Pi, Orange Pi. This is a very compact and high resolution IR imager.

Flir raspberry pi