Single chip microcomputer nixie tube stopwatch

  Single chip microcomputer operation ： Using the timer of single chip microcomputer to design a 0-99 Stop watch , Press the button S1 The stopwatch starts counting from zero , Press the button S2 The stopwatch stops , And display the final second timing value . Run the video in seconds ( We can pay attention to the official account MCU Learning notes reply Nixie tube stopwatch Get job engineering )：

1. Interface information

      The code breaking terminal of nixie tube is connected with the of single chip microcomputer P0 mouth , Bit selective termination is connected to the of single chip microcomputer P2.4、P2.5、P2.6、P2.7. The thousand and hundred bits of the nixie tube display the second count , Ten bit timer interrupt count .

2. Program code

The timer is initialized to the working mode 1, The timer timing time is 20ms, That is, the time of each overflow of the timer is 20ms, Then overflow 50 The second is the second 1 Second . By querying the value of the overflow flag bit .

void timer_inial()

{

TMOD = 0X01;//

TH0=0XB8;// timing 0.02s

TL0=0X00;

}

Timer overflow handler ： After each overflow , To manually clear the overflow flag bit , Then reinstall the initial value . At the same time, the second count value is added 1, Add up 50 Once in a second .

void second_cal_show()

{

  if(TF0==1)

{

TF0=0;

       TH0=0XB8;

TL0=0X00;

time_count++;

if(time_count>=50)//50 One second at a time

{

  time_count=0;

 time_S++;

}

}

}

The main function ： Mainly timer initialization , Then cycle the key to start 、 Key stop 、 Timer overflow processing and refresh nixie tube display function .

void main()

{

timer_inial();

  

while(1)

{

 start();

 stop();

 second_cal_show();

 LEDdisplay(time_S*100+time_count*2);

}

}

The following is the full code of the job ：

#include <reg52.h>

#include <stdio.h>

// Define two bit variables , Corresponding to the start button and stop reset button respectively

sbit key_set=P3^2;

sbit key_reset=P3^3;

unsigned char time_count=0;

unsigned int time_S=0;

#define LED_PORT P0

sbit wela_1 = P2^4;

sbit wela_2 = P2^5;

sbit wela_3 = P2^6;

sbit wela_4 = P2^7;

sbit dp=P0^7;

//LED Display font 0-F Gongyang mode

unsigned code table[]= {0Xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e};

void timer_inial();// Timer initialization

void delay(unsigned int i);// The time delay function

void start();

void stop();

void second_cal_show();

/*******************************************************************************

* Letter Count name ：Delayms

* The functionality ： Realization ms Level delay

* transport     Enter into ：ms

* transport     Out ： nothing

*******************************************************************************/

void Delay_ms(unsigned int ms)

{

unsigned int i,j;

for(i=0;i<ms;i++)

#if FOSC == 11059200L

for(j=0;j<114;j++);

#elif FOSC == 12000000L

  for(j=0;j<123;j++);

#elif FOSC == 24000000L

for(j=0;j<249;j++);

#else

for(j=0;j<114;j++);

#endif

}

/*******************************************************************************

* Letter Count name ：LEDdisplay

* The functionality ： Cycle the data on each bit

* transport     Enter into ：num Data to display

* transport     Out ： nothing

*******************************************************************************/

void LEDdisplay(unsigned int num)

{

unsigned char qian,bai,shi,ge;

qian=num/1000;

bai=num%1000/100;

shi=num%100/10;

ge=num%10;

     

wela_1 = 1;   // Turn off all nixie tubes

wela_2 = 1;

wela_3 = 1;

wela_4 = 1;

wela_4=0;  // Display thousands

LED_PORT=table[qian];

Delay_ms(1);

LED_PORT = 0xff;

wela_4=1;

wela_3=0;  // Display hundreds

LED_PORT=table[bai];

Delay_ms(1);

LED_PORT = 0xff;

//dp=0;

wela_3=1;

wela_3=0;  // Display hundreds

dp=0;

Delay_ms(1);

LED_PORT = 0xff;

wela_3=1;

wela_2=0;  // Show ten

LED_PORT=table[shi];

Delay_ms(1);

LED_PORT = 0xff;

wela_2=1;

wela_1=0;  // Display a bit

LED_PORT=table[ge];

Delay_ms(1);

LED_PORT = 0xff;

}

void main()

{

timer_inial();

  

while(1)

{

 start();

 stop();

 second_cal_show();

 LEDdisplay(time_S*100+time_count);

}

}

void timer_inial()

{

TMOD = 0X01;//

TH0=0XB8;// timing 0.02s

TL0=0X00;

}

// The time delay function

void delay(unsigned int i)

{

unsigned int k;

  for(k=0;k<i;k++);

}

void start()

{

if(0==key_set)

 {

 delay(1200);//10ms Desquamation

 if(0==key_set)// Check whether the key is pressed again

 {

while(!key_set);// Wait for the key to release

  TR0=1;

  time_S=0;

  time_count=0;

 }

 }

}

void stop()

{

  if(0==key_reset)

 {

 delay(1200);//10ms Desquamation

 if(0==key_reset)// Check whether the key is pressed again

 {

while(!key_reset);// Wait for the key to release

  TR0=0;

 }

 }

}

void second_cal_show()

{

  if(TF0==1)

{

TF0=0;

  TH0=0XB8;

TL0=0X00;

time_count++;

if(time_count>=50)//50 One second at a time

{

  time_count=0;

time_S++;

}

}

}