Last week I ordered an ST32VLDISCOVERY evaluation board out of curiosity - what can you do much wrong
when paying about US$ 10 for an evaluation board with
- a 32-Bit ARM Cortex-M3 MCU (128k Flash, 8k RAM) - STM32F100RBT6B
- an integrated SWD (Single Wire Debug) debug adapter (they use a more powerful STM32F103 than the actual MCU for this and call it Embedded ST-LINK)
that can be used as a stand-alone SWD debugger/emulator interface for other STM32 based boards as well
- all 64 pins of the STM32100 are brought out on extension headers
- 2 user LEDs and one user push button
The advertisement that caught my attention claimed: "Extension header for all QFP64 I/Os for quick connection to prototyping board or easy probing".
The board (I got from Farnell) comes in a transparent plastic sales box - with a card containing some short getting started instructions and links - without any visible static protection. After unpacking the board - you actually have to hold it by the pins to pull it out - I faced the first problem - it won't fit on any of my numerous breadboards! The two main header rows are spaced too wide apart (about 30,5 mm, exceeding the width of the breadboarding area) and the short header row at the small side opposite to the USB connector makes it completely impossible to insert the board into (a) breadboards (the 6 pins PB10 ... PB15 either collide with solid areas or will get shorted).
But then I took two half-sized breadboards and inserted each of the long header rows in one of them ... works perfect (see picture below)! An other good thing is that the pins stick out a good way above the board, enough to attach LA probe cables or female flywires directly!
Power can be either applied via the USB connector - an USB cable is not included in the kit! - or via the header pins (5V or 3V3 and GND) due two protection diodes. :)
How to get started? All essential documentation and links to the software can be found on the STM32VLDISCOVERY
page - user manual for the board and the STM32VLDISCOVERY firmware package. ST provides easy to follow introductions that explain how to develope and debug code for the STM32VLDISCOVERY for 3 development environments
- IAR Embedded Workbench
- Keil MDK-ARM
- Atollic TrueSTUDIO
Free versions can be downloaded from the manufacturers' websites - so they are code limited they are sufficient to compile all examples provided and to do some serious evaluation. It's a good starting point, later you can switch to a GCC based free toolchain. For this I chose Atollic TrueSTUDIO STM32 Lite
version as it's Eclipse/GCC/GDB based. However, the Lite version supports C only but not C++.
You may want to try the STM32 ST-Link Utility
) as well - it's a stand-alone tool that makes use of the onboard ST-Link interface and allows programming, erasing, tracing, single-stepping and viewing the MCUs core registers from outside the development environment.
For about US$ 10 you get a well designed basic 32-bit ARM Cortex-M3 evaluation board with an integrated SWD debug interface that's supported with good documentation and software. In contrast to many if not most other much more expensive evaluation kits you see these days, this one has (almost) no restrictions - all pins are easily available and can be used for experiments and designs. It's a perfect platform to start exploring the STM32 (value) line of MCUs and for your own perfboard projects.