This is the famous Arduino compatible board that based on STM32F103C8T6 ARM Microcontroller. STM32F103C8T6 is ARM Cortex-M3 core from STMicrcoelectronics. This board is often called the Blue Pill (Matrix reference). Of course with the 32-bit ARM CPU, it can easily beat Arduino UNO in performance. As an added bonus, you can easily program this board using your Arduino IDE.
With the pre-soldered header pin, you can start using this powerful Arduino compatible board out of the box :)
In case you like to watch video, here is another guide from Joop Brokking:
Warranty Period: 12 months
Features
MCU: STM32F103C8T6
Core: Single Core, Arm Cortex-M3
Operating Voltage: 3.3VDC
Max. Clock Speed: 72MHz
FLASH: 64KB
SRAM: 20KB
HSI: 8MHz
LSI: 40KHz
HSE: 8MHz
LSE: 32.768kHz
GPIO Pins – 32 with external interrupt capability
Timers – 3 16-bit Timers, 1 16-bit PWM Timer
PWM Pins – 15
Analog – 10 Channels of 12-bit ADC
I2C – 2 I2C Peripherals
USART – 3 USART Peripherals with hardware control
SPI – 2 SPI Peripherals
Other Peripherals – USB 2.0 Full Speed, CAN 2.0B
Power Sources
Any +3.3V pin (+3.3V)
Any +5V pin (+5V)
USB connector (+5V)
PCB Size: (w x l)23mm x 53mm
Note: The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time.
Note: This board may have a wrong value of resistor on the USB D+ pin. Instead of a 1.5kΩ, it has either a 10kΩ or 4.7kΩ resistor. This can be solved by replacing the resistor with the right value.