STM32 W25Qxx
This page describes how to use W25Qxx Serial Flash/EEPROM chips with the STM32. The examples and code on this page has been developed on and for the Black Pill development board.
Black Pill EEPROM
The Black Pill boards, whether original or copy, all includes an unpopulated footprint on the back side, with space for a "generic eeprom". This footprint can be populated with a wide range of compatible EEPROM chips.
The examples on this page are all using a Black Pill with a Winbond W25Q128.
The original Black Pill board have been going through a few changes which can be a bit confusing. In all cases, the footprint is wired up to SPI1, but it is important to notice that on some boards the DO (MISO) pin of the W25Qxx is wired to PA6, and on some it is wired to PB4. Be certain to check which one is actually used.
In our case, the Black Pill board is clearly not an original, and PA6 is being used throughout:
