基于STM32F1xx系列微处理器、RS485通信协议，Kill ARM开发环境下，可通过串口收发任意长度字符串的完整程序。下载至开发板后通过串口助手反复测试无误，代码清晰简洁，关键处有详细注释。-Based STM32F1xx series of microprocessors, RS485 communication protocol under Kill ARM development environment, complete program to send and receive se