Use Serial1 without including "Adafruit_TinyUSB.h"

[arms22]

Is your feature request related to a problem? Please describe.

the following code causes undefined reference to 'Adafruit_USBD_CDC::available()' when targeting the nRF52840 boards.
I understand that the header "Adafruit_TinyUSB.h" needs to be included, but I don't want to include it for power saving.

void setup() {
  Serial1.begin(115200);
}

void loop() {
}

This is because serialEventRun refers to Serial.

Adafruit_nRF52_Arduino/cores/nRF5/Uart.cpp

Line 27 in d75bb2a

if (serialEvent && Serial.available() ) serialEvent();

How about changing the call to Serial.available to a call to the weak symbol?

int Serial_available() __attribute__((weak));

void serialEventRun(void)
{
  if (serialEvent && Serial_available() ) serialEvent();
}

[hathach]

I think it is better to add the #if defined(USE_TINYUSB) && defined(NRF52840) for the Serial, if you make an PR. I will be happy to review/merge.

Update: USE_TINYUSB seems to always defined for nrf52840, i will check this out later. If you could, please make an PR for your suggestion that will make it quicker to adopt the changes.

[arms22]

I just compiled it.
I will make PR after the test.
arms22@1f4f503