The ARM PRO MINI is a tiny, open source, board based on a Cortex M0 MCU. The whole project, including schematics and BOM, is available on github.
The MCU is an NXP ARM M0 LPC11U35FHI33/501. This means that the Eclipse-based LPCXpresso IDE can be used to develop code in C/C++. Another alternative is to use the ARMmbed Online IDE (you will have to register to get to the compiler section, it is free). The ARM PRO MINI comes with a convenience library, making development easy.
The pins can be multiplexed between various functions, so the potential configurations differ a bit. The possibilities can be summarized as follows:
- 0-8 ADC channels
- Up to 26 GPIO pins
- 0-2 SPI interfaces
- 0-1 UARTs
- 0-1 I2C interfaces
- 1 USB port
- Power pins (4.5-16V in, regulated 3.3V and 5V out)
Via dangerousprototypes.