STM32F100 Breakout Board
What is it?
This is a small (1" x 3.25") board with an STM32F100C4T6B MCU, 3.3V regulator,
reset button, power LED, user GPIO LED, JTAG header and all pins brought out
to SIP headers suitable for use in a solderless breadboard. With this board
one can easily prototype small ARM Cortex M3 applications with minimum effort
What it isn't
This is not a full development system - you'll have to gather your own
programming tools, power supply, I/O devices, etc. This is not an Arduino
clone with all the low-level stuff already done for you. If you want to get by
on the cheap you'll have to be familiar with setting up an ARM GCC toolchain
as well as how to build your own copy of the latest OpenOCD JTAG downloader.
- 32-bit ARM Cortex-M3 CPU rated for 24MHz clock
- 4kB SRAM
- 16kB Flash
- 6 Timers
- 1 SPI
- 1 I2C
- 2 USART
- 1 CEC (Consumer Electronics I2C)
- 37 GPIO pins
- 10 Chl 12-bit ADC
- 2 12-bit DAC
- Note: Footprint is compatible with other 48-pin QFP parts in the STM32F100 family for additional resources.
- Onboard 3.3V Regulator (4.75V - 15V input range)
- Filtered Analog 3.3V Supply
- Power and User LEDs
- Reset button
- 20-pin JTAG compatible programming interface
- 6-pin FTDI serial compatible interface
- Fits standard solderless breadboard with 1 row exposed on each side
- J1, J2: 48 pins of direct access to the QFP pins of the MCU. Note
that J2-1 is a 5V input to the on-board regulator but all other pins
are directly connected.
- J3: 20-pin compatible JTAG connector This connector only provides
16 pins of the 20 standard, but pins 17-20 were not used so just let your
20-pin connector dangle. Be sure to align pin 1 on the cable and connector
- J4: 6-pin serial connector compatible with the FTDI USB/Serial pinout.
Use this to create devices that can talk directly to a USB host with
minimal cabling. Could also be used for bootloaders.
- JP1: Power jumper to allow the board to be powered by the FTDI
USB/Serial cable. Use caution to avoid connecting an FTDI device to local
- S1: Reset button - tied directly to the MCU reset input. Handy way to
quickly reboot your MCU after flashing new code into it.
- LED1: Power indicator - lights up when 3.3V is present.
- LED2: User GPIO - connected to GPIOB-11. Useful for diagnostics.
The STM32 family of parts are supported by a variety of commercial IDEs, all
of which are available in low-cost or limited free versions from the
I prefer to use open-source tools, so I've set up a development environment
based on the GNU C compiler for ARM, available for free from Mentor/Codesourcery.
For downloading to the target I use OpenOCD, coupled with an Olimex USB-TINY JTAG
pod. To ease development I also use the STM32 Standard Peripheral Library to
as a starting point for my code and then optimize out the heavyweight functions
as required. Links to all of these are here:
Interested? Gerbers are available in the Design Resources list above which can be used with most mail-order PCB fabs. Parts will run about $10 or so depending on
where you get them and which version of the processor you want.
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