Defining CDC_TRANSMIT_QUEUE_BUFFER_SIZE from .ino sketch

[mkals]

I'm using an STM32F4 board as a serial passthrough for programming other STM32 microprocessors. The buffer sizes set in the cdc_queue.h file are too small to allow for this application. Is there a way to set the two relevant parameters (CDC_TRANSMIT_QUEUE_BUFFER_SIZE and CDC_RECEIVE_QUEUE_BUFFER_SIZE) from the .ino sketch without modifying the library?

[fpistm]

Hi,
You can try to override it using build_opt.h but basically it is not allowed to redefine it as it is not protected by #ifndef so you should have a warning about redefinition and hope the one in build_opt will be used but I guess it should be safe for you to change it in the core.

Arduino_Core_STM32/cores/arduino/stm32/usb/cdc/cdc_queue.h

Lines 56 to 57 in 4b5098c

	#define CDC_TRANSMIT_QUEUE_BUFFER_SIZE ((uint16_t)(CDC_QUEUE_MAX_PACKET_SIZE * 2))
	#define CDC_RECEIVE_QUEUE_BUFFER_SIZE ((uint16_t)(CDC_QUEUE_MAX_PACKET_SIZE * 3))