In june 2018 I made my first SMD PCB to create a Bluepill clone. The goal was to 1) get more familiair with the ARM processors and 2) Reproduce my ATtiny84 LoRa node with less power consumption and same or smaller PCB size.
It took some time to get on the right track. With periods I had other interests of course. Now I have made a Mini Bluepill – development board version 1.0. It’s not perfect but I was able to let a blink LED every 30 seconds and in the “rest period” to get the processor in STOP mode. The power consumption was down to 3uA. On boot it was even 1.2uA.
I used the STML051C8T6 processor.
The advantage of this board is that I can solder a STM32F103CBT6 on it for more power application.
Before I made this Mini Bluepill there was another version the STM32 Development board. With this one I did not manage to get the low power consumption of a LoRa node working.
The middle 4 pins on the PCB have the same pinout as the original Blue pill*
I use the ST-LINK/V2 and and STLINK-V3MINI to program the controller. As IDE I use now STM32CubeIDE. This is a combination of STM32CubeMX and the Eclipse IDE. You can find it at st.com.
I still have to learn a lot about STM32 Arm Microcontrollers but with this achievement of low power I got a little boost to go further.
*) info on the original Blue Pill:
https://stm32-base.org/boards/STM32F103C8T6-Blue-Pill.html
https://satoshinm.github.io/blog/171212_stm32_blue_pill_arm_development_board_first_look_bare_metal_programming.html
Sometimes it is called Black Pill. They are very cheap and can be found on Aliexpress.