STC89C52 MCU matrix keyboard experiment

 Function implemented:  Complete the test of independent buttons. When one of the twenty buttons key5-key20 is pressed,
            the 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,
   to achieve the function of pressing the corresponding value to display the corresponding value.
 Experimental board model: BS-XYD-C52
 Experiment name:  Static digital tube
 Author:  Xie Yingdong
 Writing date:  2012-4-26       
/// ...

#include
#include  
                    
#define uchar unsigned char  //定义unsigned char 为 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};
 ///
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​ This is done in the same way , so if you change the frequency of the crystal oscillator , please
         make corresponding changes
 / ...


 
 
 
    
    
 

 

Function name: One_DigitalTube_displayFunction
: Complete the specified display of the digital tube on the experimental board, that is, display a specific number on a specific digital tube, such as
         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
Note: 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 reverse it
 /// ...

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
}
 ///
...
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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 is 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
 }
}