Modbus RTU to Home Assistant with TTL to RS485 electronic card and ESP01 Relay (Soft and Hard)

Some equipment such as: energy meters, solar inverters or semi-industrial equipment incorporate Modbus communication. Modbus is the protocol and RS485 is the wiring. To communicate with Home Assistant in this case we will use a TTL to RS485 card and an ESP01_Relay that consists of a card with the ESP8266 microprocessor, a 3.3V voltage regulator and a relay. In this video we will only read records from an energy meter and of course we will control the relay. First we will see how to configure and flash the microprocessor (we have to have ESPHome installed in Home assistant), then we will see how the connection is made and a little practical application. It can be mounted in a junction box without a support but we have made one with a 3D printer. Below we leave the support link: This version of the support has a space for an electronic card to house the connections and the resistance for DS18B20 temperature probes, if you are interested, ask for it in the comments and we would make another video. Electrical connection diagrams: Here code to paste: In any case, both the communication parameters, baud parity... and the addresses of the registers to be read, units, data names, etc. must adapt to the connected equipment. Parameters sensor: "Home assistant" "Modbus rtu" "tutorial" "RS485" "ESP8266" "ESP01" "Relay" "RS485 to TTL" "TTL to RS485" "ESPHome" "esp8266" "esp32" "Kostal Smart Meter"