Template library for reading SDM120 / SDM220 / SDM630 Modbus Energy meter.

Reading via Software Serial library (https://github.com/plerup/espsoftwareserial)
and rs232<->rs485 converter with automatic flow direction control (look at hardware_sdm220.jpg)
NOTE: Not work with simple max485-only converters because this lib does not control max485 DE/RE lines (at this moment)

Tested on wemos d1 mini->ESP8266 with Arduino 1.6.9 & 2.3.0 esp8266 core

crc calculation by Jaime García (https://github.com/peninquen/Modbus-Energy-Monitor-Arduino/)

2016 Reaper7

UPDATE:

• (31.10.2016) new registers for SDM120 and SDM630 by beireken (https://github.com/beireken/SDM220t)