Product parameter Model: STM32F103RET6 : ARM 32-bit -M3 CPU Size: 50 x 50mm Adjustment mode: JTAG/SWD 1, ARM 32-bit -M3 CPU up to 72MHz. Operating frequency 2, 512K bytes of program memory (ROM), 64K bytes of power 32KHz oscillator 3, embedded factory calibrated 8MHz and 40KHz RC crystal oscillator, with calibration function of 32KHz oscillator 4, power on/power off reset (POR/), programmable voltage detector (PVD) 5, 2.0~3.6 volt power supply and 1/0 pin 6, sleep, shutdown and standby mode, VBAT for backup mail (inch power supply) 7, 2 12-bit analog converter, conversion time (up to 21 input channels) Conversion range: 0 to 3.6V, triple sampling and hold function, internal temperature sensor, 8, 7-channel DMA controller, supported peripherals, timer, ADC , SPI, 12C and USART 9, Serial single-line debugging (SWD) and JEAG interface, -M3 embedded tracking module () 10, 51 multifunctional bidirectional 1/0 port, 1/0 port can be mapped to 16 external interrupts, and almost all ports can tolerate 5V signals 11, 3 general , 1 strengthening timer 12, up to 2 12C interfaces (support SMBus/PMBus) 13. Up to 3 USART interfaces 14, up to 2 SPI interfaces (18M bits/second), 2 reusable 15, CAN interface (2.0B active) 16, USB 2.0 full speed interface color: blue Material: PC+metal Different batches may have different appearance, which does not affect use. Package Contents: 1 x Development Board Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.