RS232 and RS485

ESP32 Open IoT and IIoT Gateways (P01 & P02)

The gateway is equipped with 2 transceivers MAX481 that handle transsmision in RS485 standard on each channel independently. Similar to RGB, each channel can be enabled by SIPO shift register 74HC595BQ.

To ensure transmission in RS232 standard there is also ST3232BTR IC which allows transmission on each channel independently. 

It is possible to use only one pair of each interface at the same moment, because RS232 and RS485 use the same UART pins on the MCU.