The USB port is powered by 5V, and the pin can be powered by 3.3V 5V.STM32F103C8T6 development board information: Core: ARM 32-bit Cortexx- CPU; High 72MHz operating frequency; Single cycle multiplication and hardware division; Memory:From 64K or 128K bytes of Flash program memory; Up to 20K bytes of SRAM; Clock, reset and management; 2.0~3.6V supply and I/O pins; -on/-off reset (POR/), programmable voltage monitoringLow consumption:Sleep, shutdown and standby modesV BAT powers the and backup registers2 12-bit analog-to-digital converters, 1us conversion time (up to 16 Conversion range: 0 to 3.6V,Dual sample and hold function,temperature sensor)DMA:7-channel DMA controller,Peripherals supported: timers, , SPI, I 2 C andUSART,Up to 80 fast I/O ports,26/37/51/80 I/O ports, all I/O ports can be mapped to,16 external interrupts; almost all ports are 5V tolerantDebug mode:Serial Single Wire Debug (SWD) and JTAG interfaceUp to 7 timers,3 16-bit timers, each with up to 4 forChannels for input capture/output compare/PWM or countand incremental encoder input,1 16-bit with deadband control and emergency for motorControlled PWM Advanced Control Timer,2 watchdog timers ( and windowed)System : 24-bit -decrementing counterUp to 9 communication interfacesUp to 2 I 2 C interfaces (supports SMBus/PMBus)Up to 3 USART interfaces (support ISO7816 interface,, IrDA interface and modem control)Up to 2 SPI interfaces (18Mbitsc)CAN interface (2.0B active)USB 2.0 full speed interface calculation unit, 96-bit chip codeColour: blackMaterial: ABS+metalSize: 5x3x0.2cmPackage Contents:1 * Motherboard (send pin headers but not solder)Only the above package content, other products are not included.Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.