This small green object is the ST-LINK/V2 debugger, which is a common tool for downloading programs and online debugging for STM32 and other single chip computers in embedded development ~

the bright-eyed green shell you see is self-made through 3D design and 3D printing: first draw the shell according to the size of the ST-LINK in the modeling software (such as SolidWorks and Fusion 360), reserve the USB interface and debug pin positions, then use the 3D printer to select green consumables for printing and forming, and finally install the ST-LINK motherboard ~

this self-made shell can not only protect the debugger motherboard, but also make the interface clearer through lettering (such as "STLINK-V2" and "TX/RX" logo), which is very suitable for electronics enthusiasts DIY ~

In addition, those who need internal circuit boards can be private, and the board making documents can be provided free of charge.