基于飞思卡尔单片机的车用里程传感器测试系统设计

系统采用飞思卡尔单片机MC9S12G128MLL作为下位机核心控制芯片，通过D/A控制变频器驱动交流电机并带动里程传感器，从而模拟汽车运行环境，获得里程传感器输出信号并进行处理，将处理的数据通过RS232转USB传输到PC上显示，上位机采用C#语言设计显示界面和通信程序，设计界面包括传感器运行时间，工作电压的设置、以及传感器输出信号的频率、占空比、上升沿及下降沿时间以及高低电平幅值的显示，并于相应传感器参数设置值进行比较，实现不合格参数的报警，而且测试的传感器数据可保存并能回放，上位机界面友好，操作便捷。

DESIGN OF THE AUTOMOBILE MILEAGE SENSOR TESTING SYSTEM BASED ON THE FREESCALE MICROCONTROLLER

This system uses the freescale microcontroller MC9S12G128MLL as the core control chip of the subordinate comput-er and applies D/A to controlling frequency transmitter and to driving the mileage sensor. The automotive working environment can be simulated and the signals given by the mileage sensor can be obtained and processed. Then the processed data is trans-mitted to the PC screen through RS232 to USB. The master computer uses C# language to design the display interface and the communication program. The designed interface includes the sensor running time, the operating voltage setting, the frequency of the sensor output signal, the duty ratio, the rising and falling edge time and the display of high and low amplitude, which are compared with the setting parameters of the corresponding sensor to realize the warning of unqualified parameters. Besides, the data of the tested sensor can be stored and replayed. The master computer interface is user-friendly and easy to operate.