51 single chip microcomputer controls nixie tube display

Preface

Learning today 51 Digital tube module of single chip microcomputer
The digital tube on my learning board is 4 As a whole by 12 A pin controlled module .

Today, we will program and control it to display the output we want .

The nixie tube is essentially made of 8 individual LED Made by splicing , They are called a,b,c,d,e,f,g,dp( decimal point ）. Control the lighting of these eight segments to display different results . Take the common cathode as an example （ Anode is 1 Then bright ）,0 Namely abcdef bright ,g and dp destroy , Corresponding 8 Binary is 001 1111（a It's the lowest ）. Namely 0x3f.

Here is given 0-8 Of 16 Binary code , It can be calculated and confirmed .

This kind of digital tube has a common feature , That is, one pole is connected （ Common cathode or common anode ）, Control the nixie tube by controlling the other pole .

Old rules , First look at the circuit diagram

Here we can see that it is a common cathode .
Segment selection signal and a 38 Decoder connection ,E3 Is the enable signal ,Y0 To Y7 It's the output signal , adopt SEL0,SEL1,SEL2 Three signals control the output result .（SEL by 000 Corresponding Y0,SEL by 001 Corresponding Y1······SEL by 111 Corresponding Y7）.

SEl Another chip pin P2 The lower three , We control P2 You can choose which nixie tube output , control P1 You can choose which of the nixie tubes LED Light on , This is the basic idea .

There is also a problem , Although this connection of the circuit saves a lot I/O Interface , But at the same time, only one nixie tube can have results . But the diode can be refreshed quickly , Take advantage of human visual persistence , As long as the refresh is fast enough , We can see them “ meanwhile ” Light up .（8 When two nixie tubes are on at the same time , We turn on the mobile camera , The camera is close to the digital tube , It is obvious from the mobile phone that the nixie tube is flashing and refreshing , If you don't believe it, you can have a try ）

Put the code below ： Print HNU–510

#include <STC15F2K60S2.H>

void Delay(unsigned int xms)		//@12.000MHz
{
    
	while(xms--){
    
			unsigned char i, j;

		i = 12;
		j = 169;
		do
		{
    
			while (--j);
		} while (--i);
	}
}

unsigned char duanxuan[]={
    0x76,0x37,0x3e,0x40,0x40,0x6d,0x5b,0x3f}; 
unsigned char weixuan[]={
    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07};			 

void main(){
    
	P0M0=0xff;   
	P0M1=0x00;
	P2M0=0xff;
	P2M1=0x00;
	while(1){
    
		int k=0;
		for( k=0;k<8;k++){
    
			P0=duanxuan[k];
			P2=weixuan[k];
			Delay(2);
		}
	}
}

here duanxuan The array of is the hexadecimal code that you want to output characters ,weixuan Array from 0 To 7 control P2 The lower three . Using a loop can always refresh , Achieve the desired output .

Push-pull output should be set , Here is strong pull up . The first time I didn't write, the brightness of push-pull output nixie tube display was very low , The push-pull output is bright . And that is P2 All pins are used , So when setting push-pull output P2M0=0xff, Different from the previous use of P2.3 Of P2M0=0x80.

There is also a delay 2ms It also has its function , Because too fast refresh will lead to the combination of this segment selection signal and the last bit selection signal , Some places on the nixie tube that should not be bright will have a darker light . So we add a delay function to block this combination , This step is called “ Shadow elimination ”.

The picture above shows the situation without shadow elimination .

Now let's show the effect of my code ：

It's clear , Net in vain , pure 、 good 、 The cute digital tube is really beautiful , Hey ！

Postscript

The learning of digital tube display is about to end , It will be updated continuously .
If you have any questions, welcome to communicate .
To be continued ······