Single pixel camera can scan through the range of wavelengths

Standard digital cameras can register images of narrow range of spectra. Normally this is visible light and some of IR area. If you need more specific characteristics, then price of such cameras grows exponentially. Hobbyists always try to find cheap solutions in order to get desired results. One of them is to use single pixel camera which simply scans through all image and then combines it in to picture. Single pixel is nothing more than photo-diode which can be sensitive to different wavelengths. Artyom have built a simple prototype of single pixel camera where sensitive photodiode is moved to scan all image. The idea lies in to building dark box with tiny hole in it. Image passing through that hole can be projected on the opposite plane. In order to get better image resolution he had to test various photodiodes. They have to be small size to give more resolution, but bigger sensors give less noise. This single pixel camera is universal tool. For instance if you need to register images in infrared spectra, then use IR photo diode. Visible… Continue reading

Thermal imaging with Flir Lepton sensor

Thermal imaging devices are still too expensive for non commercial use. But this doesn’t mean that those images can’t be interesting to play with on a hobby level. You could use this for inspecting electronics hots spots, detecting low temperature resistance areas around the house and do other crazy things. Andrew got a chance to play with Flir Lepton thermal imaging sensor, so he have written a driver to make it useful. Sensor has 80×60 resolution with 14bpp. This may seem low, but having in mind that each pixel detect temperature level, then it is more than enough to get useful data. He’s chosen an STM32F4 processor on a Nucleo board. The he attached Gameduino 2 which features FT800 graphical processor with fairly large LCD on top. Sensor module communicates over SPI interfaces (there is an option for I2C). In order to extend images for full screen on LCD, he used interpolation methods like simplest “Nearest neighbor”. For better results he suggests using more advanced methods like Bilinear/Linear/Sinc interpolations. Continue reading

Cheap Arduino based Thermal camera

Thermal cameras are expensive stuff as they require special CCDs that work in Infrared (IR) or Near Infrared (NIR) range. They are specialized stuff and cost much more than regular CCD. But there is always a way out when speaking about hobby level. Terence Musho was looking for cheap solution of thermal camera and found on internet ( ) a starting point. So he started working this towards this direction. The idea is simple – device uses single IR sensor which using pan-tilt motors scans area and then combines all dots in to image. This takes time, but for personal use might be a good way out. Device is controlled by Arduino which reads sensor data, drives motors and sends data points using serial interface. Computer receives pixels and produces a nice image using gnuplot. Project has one interesting feature – an ultrasonic distance sensor which additionally sends a distance to current point measured. This allows adjusting the end image depending on spot distance. Continue reading