Features: 1. Using STM32F103R8T6 as main control IC (64 pins) 2. Pin-out all pins and mark its function 3. Supports JTAG SWD debug mode 4. Leads USART1 you can use the serial download 5. RTC part may choose to use battery power or the power supply system 6. Use a jumper to select whether to use the USB interface convenient USB Development Program 7. PBO pins connected a green LED light convenient to debug. The board pre-burn the test program green LED will flash evenly when power on and send data constantly to serial port; Baud rate: 115200; Convenient to detect whether the module work normally User Manual: http://m5.img.dxcdn.com/CDDriver/CD/sku.316848.zip