RTU rework
Changes
Serial handling
This release brings a major rework of the ModbusRTU handling. The arduino-esp32 core has integrated some more ESP-IDF modifications for UART handling from version 2.0.x on that we have adopted for eModbus.
Problem was, we fixedly required a HardwareSerial as the communication object for our RTU classes. This prevented other channels like SoftwareSerial to be used instead.
Now the RTU calls will accept any object that is derived from Stream - including a HardwareSerial. Moreover the Stream object now will be passed in the begin() calls of ModbusClientRTU and ModbusServerRTU and is not needed any more in the definition of these objects..
Minor: the start/stop calls of ModbusServerRTU have been moved to begin/end for consistency with ModbusClientRTU.
Pro:
- there is no more fiddling with UART configurations inside the library any more
- other channels, like are possible now