[Introduction]：E290-400T20S is a wireless serial port module (UART) based on the PAN3060 RF chip, with multiple transmission modes, working in the ( 410.125 ~ 493.125MHz) frequency band (default 433.125MHz), using spread spectrum technology ChirpIoT™ , TTL level output.supports half-duplex wireless communication, and has the characteristics of high anti-interference and high sensitivity.