Add TCP port files to provide Modbus TCP interface for communication
Add freemodbus add tcp support for common master/slave iface and tcp example based on socket API
The communication between master and slave checked for each example serial_master, serial_slave (use ModbusPoll TCP)
update tcp example according netif changes, fix ci issues
update TCP slave implementation
update example_test.py to to set IP through stdin
update API documentation
event bit instead of semahore to lock communication resource
update default options and master/slave port files
Closes https://github.com/espressif/esp-idf/issues/858
Closes IDF-452
This example adds functionality to support basic communication in RS485 networks using Modbus protocol.
This example uses FreeModbus stack and regular UART driver API to communicate in RS485 half duplex mode.
Added initial support of modbus controller pure C api to access device parameters over Modbus transport.
Move freemodbus stack and port files into components folder
Move the modbus_controller interface into components idf folder
Source files updated after review.
Add modbus interface documentation docs/en/api-reference/protocols/modbus.rst
porttimer.c: fix bug with timer1 selected in the Kconfig
Add support of cmake system (added cmake files)
Closes https://github.com/espressif/esp-idf/issues/858
