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: PCandmetal 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. The measurement allowed error is 1-3cm.