Arduino for STM32

Nucleo boards do not have software bootloader. They use ST-Link programmer.

@Sparky
mini/micro USB is just a connector. You don't need it to use USB. Just connect D+, D- and GND.

myksj1105 Same thing. Parallel threads can be achieved only on multi core MCUs. Concurrent threads can be achieved using RTOS. There is a FreeRTOS for STM32duino: https://github.com/stm32duino/STM32FreeRTOS But concurrent multithreading should be used only if there is no other way. Jumping between ...

Nucleo board have a built-in ST-Link programmer and you probably used it to flash board.
F411 board (probably "black pill") does not have one. You need to manually reset board into bootloader mode and use DFU as an upload method.

It's saved into flash memory until it's rewritten. If you flash a big program that will need almost whole memory and without virtual EEPROM it may overwrite data saved in virtual EEPROM. Also: 1. Flash memory has limited (more then EEPROM) erase/write cycles. If you'll write lots of data or very oft...

There are no threads without a RTOS that supports threads.

@myksj1105
If you use Roger's/Steve's core then with most hardware setup you are limited to standard setup.
With STM32 core all pins connected to timers work in PWM mode.

@myksj1105
What do you mean by "desired results".
At 0 it's off, at 255, it's on.

There is no such thing as PWM mode for pins.
You can set pin in INPUT or OUTPUT (with pull-up or pull-down also) mode.
For analogWrite you don't need to set pin mode, as analogWrite does it.

How do you check if PWM works ??

... By any chance, if you want to do Serial1 through 'PB6 and PB7', How should I set it as source code? can you give me an example? (You must be busy, sorry for asking.) With STM32 core it's easy: Serial1.setTX(pin); Serial1.setRx(pin); You'll find it on STM32duino wiki: https://github.com/stm32dui...