Car dashboard introduction
The automobile instrument is composed of various instruments and indicators, especially the driver's warning light alarm, etc., to provide the driver with the required vehicle operating parameter information. According to the working principle of automobile instruments, it can be roughly divided into three generations. The first generation of automotive instrumentation is a mechanical movement watch; the second generation of automotive instrumentation is called an electrical instrumentation; the third generation is an all-digital automotive instrumentation, which is a networked, intelligent instrument with more powerful functions and display content. More rich, wire harness links are much simpler.
Most of the car instruments are third-generation instruments. It can drive the base pointer by stepper motor, or display the graphic or text information directly by using the LCD screen. At the same time he also has an intelligent processing unit that can interact with other control units of the car.
The function of the car instrument is to get the data you need and display it in a suitable way. Previous meters were generally limited to 3 to 4 displays and 4 to 5 warnings. The new meters now have about 15 displays and about 40 warnings. Different information is obtained by different acquisition methods and display modes. At present, there are three main methods for acquiring new instrument information: transmission through the body bus; conversion through A/D sampling; and acquisition through IO state change.
There are five main ways to display:
1. Drive the stepping motor to drive the ruling rotation;
2. Display graphic or digital information through a dot matrix LCD display;
3, through the segment LCD screen or digital tube display;
4, through the LED light switch display;
5. Indicate the current status by the different beeps of the buzzer.
According to the above requirements, the car dashboards designed in this paper are driven by MCU system, stepper motor LED display, LCD display, alarm function, memory function, button processing, LIN bus communication, low-speed fault-tolerant CAN bus communication and power supply. Aspects.