51 MCU Series Serial 3 - Digital Tube Static Display

Today I will mainly introduce digital tubes. In fact, after learning about light-emitting diodes, digital tubes are not difficult to understand, because the two are originally connected. First, let's take a look at the actual picture, which is basically familiar to everyone:

 

                                 

      Its internal structure is composed of 8 light-emitting diodes, but it is necessary to distinguish between common anode and common cathode, which is the same as the previous diode principle. Of course, pay attention to the order when arranging, usually from a to h.

 

                                    

       So what are dynamic display and static display? Let's take a look at the official answer. The so-called static display means that each segment code of the digital tube must occupy an output port with a latching function. The CPU sends the character code to be displayed to the output port, and the digital tube can display the corresponding character. Until the next time another character code is sent, the displayed content will not disappear; dynamic scanning is to connect the same segments of A-dp in the 8 segment codes of all displays together and connect them to a common output port, and the bit ends of the digital tube are connected to other output ports respectively, and the display effect is produced through the interaction of the two groups of signals from the two output ports. That is, let each digital tube display in turn in a certain order. As long as the scanning frequency is high enough, due to the "visual persistence" phenomenon of the human eye, it can be displayed continuously and stably.

      Next, write a few programs to make it light up:

1. One digital tube lights up

    #include

    sbit  duan=P2^2;

    sbit  wei=P2^3;

    void  main()

     {

      wei=1;

     P0=0x00;

     wei=0xbf; (The result of this statement is that the 7th digital tube lights up and displays 4)

     duan=1;

    P0=0x66;

    duan=1;

    while(1);

       }

2. Multiple digital tubes static display 

     #include

     #define  uint  unsigned  int

     #define  uchar  unsigned  char

     sbit  duan=P2^2;

     sbit  wei=P2^3;

     uchar  code  table[]=    {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};

    void  delay  (uint  z);

    void  main()

    {wei=1;

    P0=0xea;

    wei=0;

    while(1)

   {uint  num;

     for(num=0;num<16;num )

   {

   duan=1;

   P0=table[num];

   duan=0;

   delay(1000);

     }

     }

    }

 

   void  delay  (uint  z)

   {

    uint  x,y;

    for(x=z;x>0;x--)

     for(y=110;y>0;y--);

    }

 

   The above is a simple analysis of the static display of the digital tube. The dynamic one will be introduced later. In the digital tube, the main thing to solve is the bit latch and segment latch. Once you understand this, the rest is simple C language programming, which is actually not difficult!