Olimex STM32-P103

Features:

MCU

STM32F103RBT6 ARM 32 bit CORTEX M3™ 
with 128K Bytes Program Flash, 
20K Bytes RAM, 
USB, CAN, x2 I2C, x2 ADC 12 bit, 
x3 UART, x2 SPI, x3 TIMERS, 
up to 72Mhz operation

Connectors

Standard JTAG connector with ARM 2x10 pin layout for programming/debugging with ARM-JTAG
USB connector
CAN driver and connector
RS232 driver and connector
UEXT connector which allows different modules to be connected (as MOD-MP3, MOD-NRF24LR, etc)
SD-MMC connector
Backup battery connector

On-board

RESET button
Status LED
Power supply LED
Voltage regulator 3.3V with up to 800mA current
Single power supply: takes power from USB port or power supply jack
8 Mhz crystal oscillator
32768 Hz crystal and RTC backup battery connector
Extension headers for all uC ports

PCB

FR-4, 1.5 mm (0,062"), red soldermask, silkscreen component print

Dimensions

100 x 90mm (3.94 x 3.5")

Fonte: [1]