STM32L4-based RF-to-USB dongle using a low-power NRF24 2.4GHz transceiver.
4-layer PCB designed in KiCad. Video: https://www.youtube.com/watch?v=14_jh3nLSsU
You can order this board (incl. SMT assembly) at https://www.jlcpcb.com. Gerber and assembly files are in the relevant repo folders.