STM32 Minimum Development Board

Overview

The STM32 Minimum Development Board, is a popular and inexpensive breadboard-friendly breakout board for the STM32F103x8 CPU. There are two variants of the board:

Zephyr applications can use the stm32_min_dev_blue or stm32_min_dev_black board configuration to use these boards.

STM32 Minimum Development Board

STM32 Minimum Development Board

As the name suggests, these boards have the bare minimum components required to power on the CPU. For practical use, you’ll need to add additional components and circuits using a breadboard, for example.

Pin Mapping

This port is a starting point for your own customizations and not a complete port for a specific board. Most of the GPIOs on the STM32 SoC has been exposed in the external header with silk screen labels that match the SoC’s pin names.

Each board vendor has their own variations in pin mapping on their boards’ external connectors and placement of components. Many vendors use port PC13/PB12 for connecting an LED, so only this device is supported by our Zephyr port. Additional device support is left for the user to implement.

More information on hooking up peripherals and lengthy how to articles can be found at EmbedJournal.

STLinkV2 connection:

The board can be flashed by using STLinkV2 with the following connections.

Pin STLINKv2
G GND
CLK Clock
IO SW IO
V3 VCC

Boot Configuration

The boot configuration for this board is configured through jumpers on B0 (Boot 0) and B1 (Boot 1). The pins B0 and B1 are present in between logic 0 and 1 lines. The silk screen on the PCB reads BX- or BX+ to indicate 0 and 1 logic lines for B0 and B1 respectively.

Boot 1 Boot 0 Boot Mode Aliasing
X 0 Main Flash Memory Main flash memory is selected as boot space
0 1 System Memory System memory is selected as boot space
1 1 Embedded SRAM Embedded SRAM is selected as boot space

Supported Features

The on-board 8Mhz crystal is used to produce a 72Mhz system clock with PLL. The stm32_min_dev board configuration supports the following hardware features:

Interface Controller Driver/Component
NVIC on-chip nested vectored interrupt controller
SYSTICK on-chip system clock
UART on-chip serial port
GPIO on-chip gpio
I2C on-chip i2c
PWM on-chip pwm
SPI on-chip spi
USB on-chip USB device

Other hardware features are not supported by the Zephyr kernel.

I2C

The STM32 Minimum Development Board board supports two I2C devices. The default I2C mapping for Zephyr is:

  • I2C1_SCL : PB6
  • I2C1_SDA : PB7
  • I2C2_SCL : PB10
  • I2C2_SDA : PB11

Programming and Debugging

Applications for the stm32_min_dev_(blue|black) board configuration can be built and flashed in the usual way (see Build an Application and Run an Application for more details).

Flashing

Here is an example for the Blinky Application application.

Using west:

# From the root of the zephyr repository
west build -b stm32_min_dev_blue samples/basic/blinky
west flash

Using CMake and ninja:

# From the root of the zephyr repository
# Use cmake to configure a Ninja-based buildsystem:
cmake -B build -GNinja -DBOARD=stm32_min_dev_blue samples/basic/blinky

# Now run ninja on the generated build system:
ninja -C build
ninja -C build flash

Debugging

You can debug an application in the usual way. Here is an example for the Hello World application.

Using west:

# From the root of the zephyr repository
west debug

Using CMake and ninja:

# From the root of the zephyr repository
# If you already ran cmake with -Bbuild, you can skip this step and run ninja directly.
cmake -B build -GNinja -DBOARD=stm32_min_dev_blue samples/hello_world

# Now run ninja on the generated build system:
ninja -C build debug