Arduino for STM32

Have you tried library "SdFat" ? See below example.
viewtopic.php?f=39&t=1211

It looking interesting that the SPI clock is that slow. Usually when I run Arduino code on STM32 I need to review if the device can cope with the SP clock rate as STM32 is faster than Arduino.

Go to the 1.9.0 release: https://github.com/stm32duino/Arduino_Core_STM32/tree/1.9.0 Scroll further down and you shall see: Getting Started This repo is available as a package usable with Arduino Boards Manager. Use this link in the "Additional Boards Managers URLs" field: https://github.c...

I ran the Adafruit example on a blackpill but did not see your issues. I even did not add pull up resistors. The I2C address of my OLED is 0x3C instead of the default 0x3D in the code.

Have not encountered your issue with Adafruit library. Since I2C scanner did not always work it implied some sort of intermittent connection. You may also try reducing the values of the pull up resistors. Regarding the problem with u8g2 library, an user had found a fix by swapping 2 lines of code: h...

Vbus (USB) and 5V are connected together on the board. So you should either power the board via external 5V or via Vbus of the USB. Do not connect both at the same time.

Below is what I encountered: https://www.stm32duino.com/viewtopic.php?f=7&t=1196 In addition, depending on the drivers you use, the board will be recognized as: DFU if from early DeFuse Demo Bootloader if from STM32CubeProgrammer In the end I keep using ST-Link to flash the boards as DFU mode do...

The behaviour is expected on Nucleo F103RB and Generic F103RB because they have different pin number/name definitions.

By default Nucleo 64 STM32L053R8 has Serial2 connected to on-board STLink. So you need to change your code from Serial to Serial2 and connect your PC to the STLink USB port. If you want to use Serial1 you need to add below and connect the port to PC via a USB-Serial converter: HardwareSerial Serial1...

There are quite many users who don't know how to operate their new devices or gadgets because they don't read the manuals out of their excitement.

On the front page of this forum there is a section: NEW USERS START HERE ......