基于stm32及L298芯片的电机驱动及pwm调速控制，可简单实现左转，右转，后转，停步-And motor-driven and based stm32 pwm speed control L298 chip can be achieved simply turn left, turn right, after the turn, stop

stm32 USART3用作RS485通信，7数据位，偶校验，1停止位。-USART3 STM32 used as RS485 communication, 7 data bits, parity check, 1 stop bit.