完整的MP3设计代码，包括固件电路图分析和驱动程序。-MP3 complete the design code, including firmware and driver circuit analysis.

对步进电机原理和驱动方式的详细介绍及分析，对我们在做步进电机驱动程序和硬件电路时很有帮助-Principle of stepper motor and drive means a detailed descr iption and analysis, we are doing stepper motor driver and the hardware circuit helpful