You can find a lot of interesting project on the internet. Radar measurement of speed is a little bit unsual, but why can you made it?
With this tutorial, you use development board with STM32L476 and segmented LCD.
The principle of radar is Doppler efect.
The radar frequency is 10.525 GHz and you easily buy on stores for a few dolars, the name of radar module is HB100.
Whole article is here: https://www.rs-online.com/designspark/creating-a-radar-speed-detector-with-a-stm32l476-discovery-board
Github project: https://github.com/frisnit/STM32L476-radar
See also: For a much more advanced open-source radar approach using a 16-element phased array and FPGA signal processing, check out AERIS-10 – same X-band (10.5 GHz), but with up to 20 km range and full schematics under MIT license.
