Features:

• USB-B connector for providing +5V + UART communication
• On-board FTDI FT232RL for UART communication & programming (attached to the MCU's USART1)
• Dedicated LP2985-3.3 for providing 3V3 (i.e. for powering the MCU and peripherals
• On-board 24LC08 8kbit I2C EEPROM
• Dedicated SWD header for interfacing with the board via ST-Link (v2)
• 2 user-programmable on-board LEDs (triggered via MOSFETs to limit current sourcing via the MCU)
• Dedicated power status LEDs for indicating presence of: VCC, VBUS, +5V (VBUS after the USB protection diode), 3V3 via the LP2985 LDO, 3V3 via the FT232RL
• Boot mode selector jumpers
• 3V3 selection jumpers
• Reset button
• STM32F103CBT6 MCU (128K flash)

Code samples: https://github.com/l00pu5/ARMduino

This project will be superseded by its successor, ARMduino2: https://hackaday.io/project/165184-armduino2