4*4 matrix keyboard input digital tube based on stc89c52

////////////////////////////////////////////////////////////////////////////////////////
 Function implemented: Complete the test of independent keys. When one of the twenty keys, key5-key20, is pressed, a
             specific value will be displayed on the first digital tube of the development board. The displayed value is
    defined as follows: when key5 is pressed, 0 is displayed; when key6 is pressed, 2 is displayed; and so on,
    until the corresponding value is displayed when the corresponding value is pressed.
 Experiment board model: BS-XYD-C52
 Experiment name: Static digital tube
 Author: TabLee
 Date of writing: 2014-3-21     
////////////////////////////////////////////////////////////////////////////////

#include
#include
                   
#define uchar unsigned char //Define unsigned char as uchar
#define uint unsigned int

sbit Duan = P2^6; //Define the segment selection enable terminal of the digital tube
sbit Wei = P2^7; //Define the bit selection enable terminal of the digital tube

#define Digital_tube_Wei_Enable Wei=1; //Turn on the bit select enable terminal for controlling the digital tube
#define Digital_tube_Wei_Disable Wei=0; //Turn off the bit select enable terminal for controlling the digital tube

#define Digital_tube_Duan_Enable Duan=1; //Turn on the segment selection enable terminal for controlling the digital tube
#define Digital_tube_Duan_Disable Duan=0; //Turn off the segment selection enable terminal for controlling the digital tube

#define Digital_tube_Duan P0 //Define the digital tube data port

#define KEY_DOWN 0
#define Keyport P3

uchar code Dis_table[]= //Convert BCD code into array of digital tube scan code
{0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,
                                                            0x79,0x71};
uchar code Dis_Position[]= //Define array of digital tube position selection
{0xfe,0xfd,0xfb,0xf7,0xef,0xdf};
 ///
...
​
​
          ​
    ​
​No
precautions: This experiment realizes millisecond delay under the premise that the crystal oscillator used is 12M. This function is completed in
          the form ,      so  if the frequency  of  the crystal oscillator is changed, please make corresponding  changes
 /      ...  ////////////////////////////////////////////////////////////////////////////////

Function name: One_DigitalTube_display
Function function: Complete the specified display of the digital tube on the experimental board, that is, display a specific number on a specific digital tube, than
          displaying 0 on the first digital tube
Parameter introduction: uData: BCD code array of the number to be displayed
          uNumber: Select which digital tube to display, that is, let a specific digital tube display
Return value: None
Notes: The digital tube on the experimental board is a common cathode digital tube. If you use a common anode digital tube, be careful
          not to get it reversed
 / ...

void One_DigitalTube_display(uchar uData,uchar uNumber)
{
  Digital_tube_Duan=Dis_Position[uNumber]; //Light up a specific digital tube
  Digital_tube_Wei_Enable; //Enable the bit selection of the digital tube
  Digital_tube_Wei_Disable; //Disable the bit selection of the digital tube
  DelayMs(5); //Adjust the timing to achieve stable display
 
  Digital_tube_Duan_Enable; //Enable the segment selection of the digital tube
  Digital_tube_Duan=Dis_table[uData]; //Enter the value to be displayed
  Digital_tube_Duan_Disable; //Disable the segment selection of the digital tube
}
 ///
...
​    ​
          ​​​ ​

void Scan_Keyboard()
{
 uchar cTemp_Value;
 //Scan the first column of the matrix keyboardKeyport
 =0xef; //Assign a specific value to the keyboard port to achieve the following detectioncTemp_Value
 =Keyport; //Assign the keyboard port value to a temporary variableif
 (cTemp_Value!=0xef)
 {
  DelayMs(10); //Eliminate jitter, that is, eliminate interferencecTemp_Value
        =Keyport; //Reassign to temporary valueif
        (cTemp_Value!=0xef) //Check againwhile
        ((Keyport&0x0F)!=0x0F) //Judge again whether a key is pressed
  {
      switch(cTemp_Value)   
      {
       case 0xee:
         One_DigitalTube_display(0,0);break; //The fifth key is pressed, display 0
       case 0xed:
         One_DigitalTube_display(4,0);break; //The ninth key is pressed, display 4
       case 0xeb:
         One_DigitalTube_display(8,0);break; //The thirteenth button is pressed, and 8 is displayed
       case 0xe7:
         One_DigitalTube_display(12,0);break; //The seventeenth button is pressed, and C is displayed
      }
  }
 }
 //Scan the second column of the matrix keyboard
 Keyport=0xdf; //Assign a specific value to the keyboard port to achieve the following detection
 cTemp_Value=Keyport; //Assign the keyboard port value to a temporary variable
 if(cTemp_Value!=0xdf)
 {
  DelayMs(10); //Eliminate jitter, that is, eliminate interference
        cTemp_Value=Keyport; //Reassign to the temporary value
        if(cTemp_Value!=0xdf) //Check again
        while((Keyport&0x0F)!=0x0F) //Judge again whether a button is pressed
  {
      switch(cTemp_Value)   
      {
       case 0xde:
         One_DigitalTube_display(1,0);break; //The sixth button is pressed, and 1 is displayed
       case 0xdd:
         One_DigitalTube_display(5,0);break; //The tenth key is pressed, and 5 is displayed
       case 0xdb:
         One_DigitalTube_display(9,0);break; //The fourteenth key is pressed, and 9 is displayed
       case 0xd7:
         One_DigitalTube_display(13,0);break; //The eighteenth key is pressed, and D is displayed
      }
  }
 }
 //Scan the third column of the matrix
 keyboardKeyport=0xbf; //Assign a specific value to the keyboard port to achieve the following detection
 cTemp_Value=Keyport; //Assign the keyboard port value to a temporary variableif
 (cTemp_Value!=0xbf)
 {
  DelayMs(10); //Eliminate jitter, that is, eliminate interferencecTemp_Value
        =Keyport; //Reassign to the temporary valueif
        (cTemp_Value!=0xbf) //Check againwhile
        ((Keyport&0x0F)!=0x0F) //Judge whether a key is pressed again
  {
      switch(cTemp_Value)   
      {
       case 0xbe:
         One_DigitalTube_display(2,0);break; //The seventh button is pressed, and the display shows 2
       case 0xbd:
         One_DigitalTube_display(6,0);break; //The eleventh button is pressed, and the display shows 6
       case 0xbb:
         One_DigitalTube_display(10,0);break; //The fifteenth button is pressed, and the display shows A
       case 0xb7:
         One_DigitalTube_display(14,0);break; //The nineteenth button is pressed, and the display shows E
      }
  }
 }
 //Scan the fourth column of the matrix keyboard
 Keyport=0x7f; //Assign specific values ​​to the keyboard port to implement subsequent detection
 cTemp_Value=Keyport; //Assign the keyboard port value to the temporary variable
 if(cTemp_Value!=0x7f)
 {
  DelayMs(10); //Eliminate jitter, that is, eliminate interference
        cTemp_Value=Keyport; //Reassign to the temporary value
        if(cTemp_Value!=0x7f) //Check again
        while((Keyport&0x0F)!=0x0F) //Judge again whether a key is pressed
  {
      switch(cTemp_Value)   
      {
       case 0x7e:
         One_DigitalTube_display(3,0);break; //The eighth key is pressed, and 3 is displayed
       case 0x7d:
         One_DigitalTube_display(7,0);break; //The twelfth key is pressed, and 7 is displayed
       case 0x7b:
         One_DigitalTube_display(11,0);break; //The sixteenth key is pressed, and B is displayed
       case 0x77:
         One_DigitalTube_display(15,0);break; //The 20th button is pressed, and F is displayed
      }
  }
 }
}
/// ...

Function name: mainFunction
function: Continuously scan the keyboard in a loop. When a key is pressed, the corresponding value will be displayed on the digital tube.
Parameter introduction: None
Return value: None
Notes: None
/ ...

void main()
{
 DelayMs(50);
 while(1)
 {
  Scan_Keyboard(); //Call keyboard scanning function
 }
}