KEIL C51开发，自用程序，完美测试通过，STC8A8K64S4 读取SHT20温湿度 BMP280气压数据，I2C协议，STC8A8K64S4 时钟选22.1184M(STC8A8K64S4 read SHT20 temperature and humidity BMP280 air pressure data, I2C protocol)

STC8A8K单片机与上位机，电脑进行485通信，485进行发送，485进行接收(Stc8a8k single chip microcomputer communicates with upper computer and computer in 485, sends and receives in 485)