Keyboard scanning-digital tube incremental display program-EEWORLD

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/*
Program effect: The 51 single-chip computer key scans the digital tube display input, and the digital tube is displayed in increments, just like
inputting a number when making a phone call. The program is simple and compact
and relatively difficult to understand, but as long as you understand the previous program, this program
can be understood.
Programmer: http://www.51hei.com Please keep the copyright when reprinting.
Note: If you can't compile in Keil, please delete all leading blanks in each line,
*/
#include //Header file
#include
#define uchar unsigned char //Macro definition
#define uint unsigned int
sbit jdq=P3^5; //Bit declaration, drive relay pin
sbit fmq=P3^4; //Bit declaration, drive buzzer pin
code uchar table[]={0x3f,0x06,0x5b,//Number displayed by digital tube
0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,
0x77,0x7c,0x39,0x5e,0x79,0x71};
code uchar key_tab[17]={ //This array is the keyboard code
0xed,0x7e,0x7d,0x7b, // 0，1，2，3，
0xbe,0xbd,0xbb,0xde, // 4，5，6，7，
0xdd,0xdb,0x77,0xb7, // 8，9，a， b，
0xee,0xeb,0xd7,0xe7,0xff}; // c，d，e，f，
uchar l_tmpdata[8]={0,0,0,0,0,0,0,0,0};
uchar l_key=0xff; //Define variables to store key values
uchar l_keyold=0xff;//As a credential for whether the key is released
void readkey(); //Sub-function to get the key value
void display(uchar *lp,uchar lc); //Display sub-function
void delay(); //Delay sub-function
void init(); //Initialization sub-function
void main() //Main function
{
init(); //Call the initialization sub-function
}
void init()
{
uchar i,j; //Define local variableswhile
(1)
{
readkey(); //Call the key value acquisition sub-function, that is, scan the keyboard and obtain the key
valueif((l_keyold!=0xff)&&(l_key<10)) //Only the keys 0-9 are processed
{
if(j<8) //Use j to represent the number of keys pressed, no more than 8j
++;
for(i=j-1;i>0;i--) //Circular shift
datal_tmpdata[i]=l_tmpdata[i-1];
l_tmpdata[0]=l_key; //After shifting the data, add the newly input data to
the taill_key=0xff;
}
display(l_tmpdata,j); //Output the obtained key code value
}
}
void readkey() //Sub-function to obtain the key value
{
uchar i,j,key;
j=0xfe; //Set the initial
valuekey=0xff;
for(i=0;i<4;i++) //The lower 4 bits of port P0 output 0 in a loop and scan the keyboard
{
P0=j;
if((P0&0xf0)!=0xf0) //Judge whether a key is pressed, if so: the upper 4 bits cannot all be 1
{
key=P0; //Read the value of P0 and exit the loop, otherwise continue the loop
break;
}
j=_crol_(j,1); //The function of this function is: left shift and circular shift
}
if(key==0xff) //If the value of port P0 cannot be read, such as interference, no processing is done
{
l_keyold=0xff;
fmq=1; //The button is released and the buzzer stops
ringingreturn;
}
if(l_keyold==key) //Check whether the button is released, if they are equal, it is not releasedreturn
;
fmq=0; //The button is pressed and the buzzer
soundsl_keyold=key; //Get the key code as a certificate
for releasefor(i=0;i<17;i++) //Look up the table to get the corresponding hexadecimal value and store it in l_key
{
if (key==key_tab[i])
{
l_key=i;
break;
}
}
}
void display(uchar *lp,uchar lc)//display sub-function
{
uchar i;
P2=0;
P1=0x07; //light up the eighth digital tubefor
(i=0;i {
P2=table[lp[i]];
delay();
P2=0;
if(i==7)
break;
P1--;
}
}
void delay()//delay sub-function, that is, five empty instructions
{
_nop_();_nop_();_nop_();_nop_();_nop_();
}
Note: If it cannot be compiled, please delete all leading spaces in each line.

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