Drop official support for AVR for this library.

[aentinger]

This is imho necessary since even one of our own examples does not link anymore, due to the required memory exceeding the available ressources of the ATMEGA328P based Arduino Nano.

[github-actions]

Memory usage change @ ab8d8f8

Board	flash	%	RAM for global variables	%
arduino:mbed_nano:nano33ble	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:mbed_portenta:envie_m7	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:megaavr:uno2018:mode=off	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrwifi1010	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0

Click for full report table

Board	examples/RTU/ModbusRTUClientKitchenSink flash	%	examples/RTU/ModbusRTUClientKitchenSink RAM for global variables	%	examples/RTU/ModbusRTUClientToggle flash	%	examples/RTU/ModbusRTUClientToggle RAM for global variables	%	examples/RTU/ModbusRTUServerKitchenSink flash	%	examples/RTU/ModbusRTUServerKitchenSink RAM for global variables	%	examples/RTU/ModbusRTUServerLED flash	%	examples/RTU/ModbusRTUServerLED RAM for global variables	%	examples/RTU/ModbusRTUTemperatureSensor flash	%	examples/RTU/ModbusRTUTemperatureSensor RAM for global variables	%	examples/TCP/EthernetModbusClientToggle flash	%	examples/TCP/EthernetModbusClientToggle RAM for global variables	%	examples/TCP/EthernetModbusServerLED flash	%	examples/TCP/EthernetModbusServerLED RAM for global variables	%	examples/TCP/WiFiModbusClientToggle flash	%	examples/TCP/WiFiModbusClientToggle RAM for global variables	%	examples/TCP/WiFiModbusServerLED flash	%	examples/TCP/WiFiModbusServerLED RAM for global variables	%
arduino:mbed_nano:nano33ble	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0
arduino:mbed_portenta:envie_m7	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0
arduino:megaavr:uno2018:mode=off	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0
arduino:samd:mkrwifi1010	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0

Click for full report CSV

Board,examples/RTU/ModbusRTUClientKitchenSink<br>flash,%,examples/RTU/ModbusRTUClientKitchenSink<br>RAM for global variables,%,examples/RTU/ModbusRTUClientToggle<br>flash,%,examples/RTU/ModbusRTUClientToggle<br>RAM for global variables,%,examples/RTU/ModbusRTUServerKitchenSink<br>flash,%,examples/RTU/ModbusRTUServerKitchenSink<br>RAM for global variables,%,examples/RTU/ModbusRTUServerLED<br>flash,%,examples/RTU/ModbusRTUServerLED<br>RAM for global variables,%,examples/RTU/ModbusRTUTemperatureSensor<br>flash,%,examples/RTU/ModbusRTUTemperatureSensor<br>RAM for global variables,%,examples/TCP/EthernetModbusClientToggle<br>flash,%,examples/TCP/EthernetModbusClientToggle<br>RAM for global variables,%,examples/TCP/EthernetModbusServerLED<br>flash,%,examples/TCP/EthernetModbusServerLED<br>RAM for global variables,%,examples/TCP/WiFiModbusClientToggle<br>flash,%,examples/TCP/WiFiModbusClientToggle<br>RAM for global variables,%,examples/TCP/WiFiModbusServerLED<br>flash,%,examples/TCP/WiFiModbusServerLED<br>RAM for global variables,%
arduino:mbed_nano:nano33ble,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0
arduino:mbed_portenta:envie_m7,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0
arduino:megaavr:uno2018:mode=off,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0
arduino:samd:mkrwifi1010,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0

[aentinger]

I'm taking action on this one. Since we are not going to fix support for Ethernet/Modbus its misleading to advertise as having compatibility with AVR when its in fact not true. Better to be honest up-front than to be dishonest and have disappointed users.