Blue Pills are nice, except that most Chinese Blue Pills have an out-of-spec pull-up resistor on D+. So, if you want to use the USB port, you have to replace th

Blue Pills are nice, except that most Chinese Blue Pills have an out-of-spec pull-up resistor on D+. So, if you want to use the USB port, you have to replace the resistor. Also, on many of them the micro-USB connectors are not soldered to they board properly and break easily. Many Blue Pills have cheap knock-off voltage regulators. Finally, recently Blue Pills have showed up with fake STM32 chips [1]. As far as I understand Black Pills fix these deficiencies, though I wouldn't be surprised if some manufacturers break Black Pills to cut some costs. I have good experience with RobotDyn's Blue Pill boards. They have the correct pull-up resistor value and a micro-USB connector that is properly attached to the boards. They also sell them with the stm32duino bootloader pre-flashed, so that you directly use them with stm32duino (Arduino for STM32) without ST-Link: https://robotdyn.com/catalog/development-boards/stm-boards-and-shields.html https://robotdyn.com/catalog/development-boards/stm-boards-a... [1] https://embeddedtronicsblog.wordpress.com/2018/12/29/fake-stm32-blue-pill-boards/ https://embeddedtronicsblog.wordpress.com/2018/12/29/fake-st...