Arduino_core_stm32: stm32f030f4p6 Serial doesn't seem to work

[mcer12]

Serial.print() doesn't output anything at any baud rate. When I use SoftwareSerial at the RX and TX gpios instead of hardware, it works. I use serial to flash the chip so it's not a connection issue. Am I missing something? Using 1.7 arduino core.

#include <SoftwareSerial.h>

SoftwareSerial mySerial(10, 9); // RX, TX

void setup() {
  mySerial.begin(9600);
}

void loop() { // run over and over
    mySerial.println("TEST");
    delay(1000);
}

Basic Serial doesn't work.

void setup() {
  Serial.begin(9600);
}

void loop() { // run over and over
    Serial.println("TEST");
    delay(1000);
}

[fpistm]

Hi @mcer12
I guess you use the DEMO board ?
I did not test it as I do not have it. It is a contribution.
Looking at the variant, I can see this:
https://github.com/stm32duino/Arduino_Core_STM32/blob/6808f06a3c183f22784f0486a3034644535c5b2b/variants/DEMO_F030F4/variant.h#L53-L54

So I guess this is the one you used to flash over serial.
Anyway, the default Serial instance has been mapped to:
https://github.com/stm32duino/Arduino_Core_STM32/blob/6808f06a3c183f22784f0486a3034644535c5b2b/variants/DEMO_F030F4/variant.h#L83-L88

Probably because PA9/PA10 are reserved for I2C.
So, you can change the default Serial like this:

void setup() {
  Serial.setRx(PA10);
  Serial.setTx(PA9);
  Serial.begin(9600);
}

void loop() { // run over and over
  Serial.println("TEST");
  delay(1000);
};

or kept default pins and connect to PA3/PA2

[mcer12]

I see, it works now, thank you. This is pretty confusing, especially looking at the pinout of the demo board
https://user-images.githubusercontent.com/20950920/48308359-6e531480-e56b-11e8-9e92-98dba779e01b.jpg
Maybe it would be worth to add this as a switch in the compiler options, if user wants to use PA9/PA10 gpios for serial or i2c?

[fpistm]

Well, all can be done. Anyway as there is only one I2C, I guess this is the best option.