Mbed is a prototype development platform for ARM processor. It includes three parts: free software library (SDK), hardware reference design (HDK) and online tools (WEB). The specific introduction of each part is as follows: SDK: mbed designs a hardware abstraction layer to mask the differences between microprocessors provided by different MCU manufacturers In other words, the application based on mbed can be easily replaced by arm microprocessors from different manufacturers, thus leaving users more choices.