RS485 Modbus library throwing errors

Hi,
I want to read some registers from a frequency inverter using a XMC4700 Relax Kit and the Arduino Modbus library. Unfortunately there are some warnings, notes and an error related to the ArduinoRS485 library. The same messages appear when compiling an example sketch of the RS485 libary.

C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp: In member function 'virtual void RS485Class::begin(long unsigned int, uint16_t, int, int)':
C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:67:34: warning: invalid conversion from 'uint16_t {aka short unsigned int}' to 'XMC_UART_MODE_t {aka XMC_UART_MODE}' [-fpermissive]
_serial->begin(baudrate, config);
^
In file included from C:\Users\me\AppData\Local\Arduino15\packages\Infineon\hardware\arm\1.6.0\cores/Arduino.h:256:0,
from C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.h:23,
from C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:20:
C:\Users\me\AppData\Local\Arduino15\packages\Infineon\hardware\arm\1.6.0\cores/HardwareSerial.h:75:10: note: initializing argument 2 of 'void HardwareSerial::begin(uint32_t, XMC_UART_MODE_t)'
void begin( uint32_t speed, XMC_UART_MODE_t config);
^
C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp: In member function 'void RS485Class::sendBreak(unsigned int)':
C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:163:29: warning: invalid conversion from 'uint16_t {aka short unsigned int}' to 'XMC_UART_MODE_t {aka XMC_UART_MODE}' [-fpermissive]
_serial->begin(_baudrate, _config);
^
In file included from C:\Users\me\AppData\Local\Arduino15\packages\Infineon\hardware\arm\1.6.0\cores/Arduino.h:256:0,
from C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.h:23,
from C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:20:
C:\Users\me\AppData\Local\Arduino15\packages\Infineon\hardware\arm\1.6.0\cores/HardwareSerial.h:75:10: note: initializing argument 2 of 'void HardwareSerial::begin(uint32_t, XMC_UART_MODE_t)'
void begin( uint32_t speed, XMC_UART_MODE_t config);
^
C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp: In member function 'void RS485Class::sendBreakMicroseconds(unsigned int)':
C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:173:29: warning: invalid conversion from 'uint16_t {aka short unsigned int}' to 'XMC_UART_MODE_t {aka XMC_UART_MODE}' [-fpermissive]
_serial->begin(_baudrate, _config);
^
In file included from C:\Users\me\AppData\Local\Arduino15\packages\Infineon\hardware\arm\1.6.0\cores/Arduino.h:256:0,
from C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.h:23,
from C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:20:
C:\Users\me\AppData\Local\Arduino15\packages\Infineon\hardware\arm\1.6.0\cores/HardwareSerial.h:75:10: note: initializing argument 2 of 'void HardwareSerial::begin(uint32_t, XMC_UART_MODE_t)'
void begin( uint32_t speed, XMC_UART_MODE_t config);
^
C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp: At global scope:
C:\Users\me\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:189:18: error: 'SERIAL_PORT_HARDWARE' was not declared in this scope
RS485Class RS485(SERIAL_PORT_HARDWARE, RS485_DEFAULT_TX_PIN, RS485_DEFAULT_DE_PIN, RS485_DEFAULT_RE_PIN);

A. XMC 4700 Relx Kit 5V
B. Lib Version 1.6.0
C. Arduino IDE Version 1.8.13
D. ArduinoRS485 Version 1.0.2: https://github.com/arduino-libraries/ArduinoRS485
ArduinoModbus Version 1.0.6: https://github.com/arduino-libraries/ArduinoModbus
Hardware: MKR 485 shield (connected only TX and RX pins)

Can you tell me where I would need to define the SERIAL_PORT_HARDWARE ?
Thanks.

Hi Kilian,

I believe those are not defined in the XMC-for-Arduino, but you can use the Serial1 instance:

XMC-for-Arduino/variants/XMC4700/config/XMC4700_Relax_Kit/pins_arduino.h

Line 476 in 4379305

extern HardwareSerial Serial1;

You can add that SERIAL_PORT_DEFINE to Serial1 and the rest of the constructor arguments (RS485Class RS485(SERIAL_PORT_HARDWARE, RS485_DEFAULT_TX_PIN, RS485_DEFAULT_DE_PIN, RS485_DEFAULT_RE_PIN);) in another #elif/#endif block here for the XMC4700 relax kit board:
https://github.com/arduino-libraries/ArduinoRS485/blob/9a6b830880a578292388f1bd36eb2ec836d29f93/src/RS485.h#L31-L40

Please be aware ArduinoRS485 is meant to be used with the Arduino MKR board with a Arduino MKR485 shield, despite claiming to be for all architectures some of the source in Arduino RS485 expects specific hardware structures that will probably only be possible for the Arduino MKR board implementation.

Personally the Arduino MKR485 board is a bit SLOW for RS485 having done several at 1Mbps and faster. 250kbps is also used over RS485 in DMX configurations for lstage lighting and effects controls

ModBUs is a communications protocol that works over many types of links RS232, RS485, Ethernet and USB for startes.

Thanks Juan and thanks @techpaul ,

The #elif method worked quite nice to eliminate the errors in the RS485 library.

#ifdef AVR
#define RS485_DEFAULT_DE_PIN 2
#define RS485_DEFAULT_RE_PIN -1
#elif defined(XMC4700_Relax_Kit)
#define RS485_DEFAULT_DE_PIN 6
#define RS485_DEFAULT_RE_PIN 8
#define SERIAL_PORT_HARDWARE Serial1
#else
#define RS485_DEFAULT_DE_PIN A6
#define RS485_DEFAULT_RE_PIN A5
#endif

Just selected pins 6 and 8 as they are currently not occupied in my application.
However about 16 new errors came up originating from the Modbus library afterwards. I was able to fix them by commenting the TRUE / FALSE definition part in modbus.h:
https://github.com/arduino-libraries/ArduinoModbus/blob/ba5d0beaec03243d26258f4edca4748ef1c3a428/src/libmodbus/modbus.h#L45-L51

Now I can compile the complete ModbusRTUClientToggle.ino example sketch without errors but with the warnings left. Need to check, if this could cause trouble, but looks good so far :)

If you are running out of pins and your devices can output 3V3 levels or handle 3V3 inputs you can have lots more pins see

https://github.com/techpaul/XMC-for-Arduino/wiki/XMC4700-Relax-Kit-X1-and-X2

Which warnings?

The ones above seem to be due to the usage of custom XMC types in begin() vs Arduino AVR core begin().

Only the warnings shown in my first post, yes.
Ahh okay then it should work. My only fear was, that a parameter declaration might exceed its memory allocation. Thanks :)