modbusRTU with STM32L4

[Rumen33]

I am trying to use the modbus RTU library with STM32L431RTC6 processor and it looks like the pulse on the direction pin of the processor is not long enough to achieve successful data transmission. I am using v. 4.1.0 of the library, but I also tried 4.1.1, without solving the problem. The processor is running at 16MHz clock freq. Data transmission speed is 9600 bps. The code was also tested with ESP32 and works great there.

I succeed to solve the problem by adding the following into ModbusSettings.h:

#if defined(ARDUINO_GENERIC_L431RCTX)
#define MODBUSRTU_FLUSH_DELAY 20
#endif

Is this a correct solution? Any support will be appreciated.