For years I’ve only used Microchip PIC and recently Arduino, but today I’ve received my first ARM board, exactly a STM32F0-Discovery board, equipped with an ARM Cortex-M0 32-bit. Surely isn’t the most powerful and complete example of ARM architecture but for less than 10€ is a nice deal!
The board itself has a very interesting price/quality ratio, we have:
- ARM Cortex-M0 32-bit RISC
- 64 Kbytes FLASH
- 8 Kbytes RAM
- RTC, timers, ADC, DAC, comparators, communication interfaces
- ST-Link USB Debugger
Both bottom headers are alligned regularly so is possible easily attach to a breadboard, leaving more time for experimenting and prototyping! On the other hand not every GPIO pin is 5V tolerant, so level-shifters (or tricks) must be taken into account in daily usage.
This green piece integrate a ST-Link USB debugger/programmer, really good since we don’t need any external stuff to start playing! ST-Link hardware is high-ligthed with red in the following picture
Embedded ST-Link
The embedded ST-Link is connected to STM32F051 processor using SWD protocol (we talk about this later) that uses only two pins for program and debug purposes. Removing jumpers from CN2 connector let us use the embedded ST-Link to program and debug other STM32 microprocessors, connecting them through the header CN3… A big deal 😉
When plugged in, automatically starts a demo program that blinks two LEDs (blue and green) and with a button is possible to change the blinking effect. Nothing special at all, but two outputs (LEDs) and an input (USER BUTTON) on board are really useful when developing firmwares (and when debugging…)
The internal mcu’s hardware architecture is completely different from the others that I’ve ever used, so it’s time to get patience and study the manual(s)
Some material can be retrieved from: http://www.st.com/web/en/catalog/tools/PF253215