STMicro STM32F401CCU6 Arm Cortex-M4F MCU @ 84 MHz with 256 KB flash, 64KB SRAM

Specifications:
Based on F4 series cheapest chip STM32F401CCU6,  But faster speed and own the float calculation function Board lead out all IOs for use.

Features:
VB can connect coin battery power supply
On board 32.768Khz crystal, and 25Mhz main crystal
Typc-C programming port
V+/V- can connect external ADC reference voltage, default to power voltage.
B2 boot select pin is selectable for boot configuring or normal GPIO.
SW debug port
Reset buttons.