Lepton-Pythonista-MicroPython

This project aims at streaming the thermal video of a FLIR Lepton on an Iphone. The video stream is retrieved by an ESP32 through the VoSPI of the Lepton and then the EPS32 sends to the Iphone through Wifi /UDP the video (no router is needed). A first program is written in Micropython for the ESP32. This one sets up the Lepton configuration through the CCI and gets the video data from the Lepton and sends it to the Iphone without any processing. A second program is written in Pythonista for the Iphone. This one processes the data received and displays the images/video. The program enables the user to choose the mode : 1) AGC (8 bit grayscale) 2) RAD /T Linear , RGB. In the second mode the user can get the temperrature through touching the screen. CAUTION : the program does not involve any calibration of the Lepton. The user can zoom, take screenshots and record videos (three buttons at the bottom of the screen for this purpose)

Hardware

• Iphone (8)
• ESP32 Wroom DevKit (from uPesy)
• jumper cables + breadboard
• Lepton 3.5
• Breakout board V2.0

Preparation

1. in boot.py set up the password and ssid
2. in main.py : set up the TIMEOUT, the streaming lasts the duration specified by TIMEOUT. If you want that the loop runs forever, replace the duration in the "while loop" by "true"
3. cabling according to the Lepton Breakout board V2.0 electrical scheme and https://lepton.flir.com/getting-started/raspberry-pi-lepton/ + MOSI grounded

Usage

• power up the ESP32, after 5 s, the blue LED blinks at 1 Hz, it means that the ESP32 waits for the mode selection coming from the Pythonista program

• in the Iphone , go to the wifi configuration panel and choose the relevant Wifi access point (that you have specified at 1) in "preparation" above). Check that the Wifi logo has appeared on the Iphone screen
• run the Pythonista program , select the mode, the blue LED of the ESP32 blinks faster (10 Hz) until the initilisation is complete

• when the initialisation is complete, the LED remains fixed, the video appears on the Iphone two seconds after
• the user can zoom (1 , 1.5, 2, 2.5, 3, whole width), take a screenshot (files are named screenshot0X.jpg, the previous files are erased)
• the user can record videos. The files are named vid0X.mp4, starting from X=0, if vid00.mp4 already exists the recording is not possible (cannot overwrite vid00.mp4) but this can be bypassed through tapping again on the record button (= will incremente the file name)
• in RAD mode (RGB), the user can get the temperature through touching the view
• Top screen : Bad CRC : information about the communication quality, usually around 20-25%. qsize :size of the queue shared between the thread that receipts the data and the one that processes the data, if everything is fine, qsize should be not more than 2 (=processing faster than data receiption). fps : frame per second, should be 9 (at least outside US, perhaps in US can be 27?). T (only in RAD mode) : temperature got after having touched the view (a white dot appears when the screen is touched, see video example)
• RGB : the palette used can be found in "Pythonista" folder, the program adapts the color range to the the current scene temperature range
• Streaming duration : see remark at 2) above in "preparation"
• during the video streaming, the user can stop the Pythonista program and run it again but the user has to choose the same mode as initially specified (it is not possible to change the mode during the streaming). Note: in this context, the view appears after 4/5 s once the mode is selected. If the user wants to switch to a different mode, the ESP32 must be reset (then the blue LED blinks at 1 Hz, etc...)