DIY mini STM32F030 development board

During the "Double 11" last year, I didn't grab a STM32F030 Nucleo32 development board, and later I felt a little regretful. Although I have Nucleo-64 and Nucleo-144, the small and exquisite Nucleo32 is indeed attractive, even if I buy it and don't use it.

In places where only extremely simple MCU functions are needed, a mini development board may be more useful. Just build one yourself. The 32-pin STM32F030 is very cheap. If you have fewer resources, you can choose a 20-pin one, but if there are too few, there is no need to make a board. 8-bit parallel data port, SPI, UART, I2C, one each, two LEDs, and two buttons.

OK, that's the design. The motherboard is smaller than Nucleo-32 because I separated the debugger. After separation, it is more flexible to use, but of course it may also lose the convenience of debugging, so I made it into a direct plug-in - ST-Link or J-Link OB, connected to mini F030 through 5 pins, plugged together horizontally.

The pins are SWCLK, GND, SWDIO, nRST, VDD3.3. I designed the J-Link OB F072 version here, which also has a USB serial port. If it needs to be connected to F030, a Dupont line is used separately. In this way, it is very simple to use J-Link alone to adjust other MCUs.

There is not much to say about the circuit diagram. The mini F030 is an I/O lead, and there is no crystal oscillator (later I thought, there is still room for a 3225 chip)

The two I/Os of the button and SWD are multiplexed, which will affect if you want to use the button and debug at the same time.

J-Link OB diagram, simpler than ST-link