Blue Pill is an amazing board for its price with all the features it brings from the MCU STM32F103C8T6. However, it does not have any builtin programmer. What I have seen, there are 3 ways to upload code to Blue Pill via Arduino:
You have to tweak the resistors in the Blue Pill and use Maple Bootloader from Roger Clark. However, the Arduino Core for this Board is slowing in the end of its life (April 2019).
Or using the FTDI for uploading code. This method can be frustrated for beginners since you have to tweak the BOOT0 and BOOT1 pin to upload code. This method can wear me down very quickly since I have to go over it again and again to successfully upload the code without it erased the code itself.
Or you can use a cheap STLink V2. This method is great. However, cheap STLink on the market does not have any UART capability. Because of that, you will have to get an additional FTDI to see the values on monitor in Arduino IDE. This method can also wear me down.
With this, I decided to create my new board: Green Pill
Green Pill solves this problem by bringing the Open Source Black Magic Probe into its design. Since Black Magic Probe has SWD Programmer and UART, this will make beginners like me to feel much easier when entering STM32 World. Also, since the board already has a builtin SWD Programmer, it is easier for me to use different MCU in STM32 family with Arduino. Currently, it supports STM32F103C8T6 and STM32F103CBT6. In the short future, I will create support for a new MCU to the Green Pill: STM32L431CCT6. A much better MCU comparing to the old STM32F103C8 with much more RAM, Flash and 5V Tolerant Pins and Power Efficiency.
Similar to MINHF4, I do not have any plans to sell this product in the future. But all of my designs and BOM file are here. If you want to manufacture this board, feel free to use this. I do hope that this design will come out as a replacement to the much love Blue Pill. And it will attract more beginners to the STM32 MCU.
Note for Potential Manufacturer: My design has two pads note as DCLK and DIO. These pads are responsible for uploading Black Magic DFU code to the IC1.
This is the Test Video for uploading code to Green Pill