The Thermal Imaging Camera is my diploma project which was necessary to get my Engineer Diploma (BSc). I got the idea for the project whilst working at Continental where I found that using a TIC (Thermal Imaging Camera) is fast and useful for hardware debugging, especially for power electronics.
I was given the MLX90621 sensor (actually 2 pcs) by Melaxis as samples for being a student, for which I am very grateful. Therefore, the development begun.
After careful consideration, I chose the components and the resulting specifications of the device can be seen below:
One thing that I have omitted from the specifications is the VGA CMOS Camera Sensor, which can be seen in the rendered picture above. Unfortunately, due to time constraints I did not have time to finish implementing this in software, but it is functional from a hardware standpoint (with proper power supplies and clock input). Otherwise, the device is fully functional. At the end of this page there is a video where you can see it working.
I have designed the PCB in Altium as I have never used it before and wanted to familiarise myself with it as it is seen as a professional tool. Below you can the unpopulated and the populated PCB. I've had them made at Elecrow and they turned out pretty great. I soldered them by hand.
I have implemented several features for this camera:
- Ironbow color palette (Similar to what FLIR uses):
- Minimum and maximum temperature selection: Manual or Automatic; Maximizing the usage of the color palette -> Better contrast
- Save data (.csv) / image (.bmp) to SD Card (the BMP implementation was such a pain to write from scratch)
- Interpolation: Nearest Neighbour and Bilinear (because the imaging sensor only has a resolution of 16 x 4). The top of two fingers:
- Panorama feature: Simply stiches 4 images which the user has to align. Panorama thermal image of my hand:
- Serial passthrough using the USB port (There is a USB to Serial IC onboard - CH340g)
- Desktop application written in electron, so the TIC becomes sort of a thermal webcam by using the serial passthrough
- Variable LCD brightness via PWM and many minor things (show FPS, select whose pixel temperature to see)
If you want to read my whole thesis based on this project I would 1. Be pleasantly surprised 2. Totally send you a copy. Use the contact form for more details, I usually try to reply as fast as possible. Finally, you can see a video of the device below: