C51 minimum system board infrared remote control LED light on and off

C51 Minimum system board infrared remote control led The light goes on and off

One 、 Preface

Because I haven't touched the SCM for a long time , And the previous code has not been well preserved , So we can't find a suitable one to refer to when we need to use infrared remote control . stay b Station to see a good effect video , But you need to add groups , After adding the group, I asked the group leader for code reference , The result is a fee , Because I am used to whoring for nothing , And the infrared remote control itself is not difficult , So I asked my classmates for the code of the infrared remote control car , I modified it , Change to control led Light out , It's basically the simplest one , If you don't understand the principle of infrared, you can use it easily . I am writing this article to facilitate migration to other projects .

Two 、 explain

1. This procedure does not include the acquisition of the key value of the infrared remote control , When buying a treasure, the merchant usually gives the key value .
2. I used a bread board to light up led Circuit , A resistor is used , The resistance value is 1k.
3. The code is not explained here , Will tell you where you can modify it and you can use it directly .

3、 ... and 、 connection

The wiring should be simple , I got the signal pin of the infrared receiver here P3^2 mouth . If you are not clear, you can comment and ask me .

Effect demonstration video ：https://www.bilibili.com/video/BV1j44y1p7Nq

Four 、 Code

#include<reg52.h> 

/* C51 Infrared remote control led The light goes on and off (51 Minimum system board )  Wiring instructions : P1^0 -- led P3^2 --  Signal terminal of infrared receiving module  */

// Function definition 
void delay(unsigned int z); 
void delay_us(unsigned int aa); 

/*====================================  Custom type name  ====================================*/
typedef unsigned char INT8U;
typedef unsigned char uchar;

typedef unsigned int INT16U;
typedef unsigned int uint;

/*====================================  Hardware interface bit declaration  ====================================*/
sbit IR  = P3^2;     // Define the infrared pulse data interface   External interrupt O Input port 
sbit led = P1^0;

uchar IRtime; 		// Detect the duration of infrared high level （ Pulse width ）
uchar IRcord[4];    // This array is used to store the separated 4 Bytes of data （ User code 2 Bytes + Key value code 2 Bytes ）
uchar IRdata[33];   // This array is used to store infrared 33 Bit data （ The first digit is the guide code and user code 16+ Key value code 16）
bit IRpro_ok, IRok;  // The first one is for infrared reception 4 Bytes complete .IRok Used to detect pulse width 

void init()	   // Initialize the timer 0  And external interruptions 0
{
    
	TMOD = 0x02; // Timer 0 Operation mode 2,8 Bit auto reassembly 
	TH0 = 0x00;  // high 8 Bit loading 0 Then the time that the timer overflows once is 256 Machine cycles 
	TL0 = 0x00;
	EA = 1;      // Total interruption 
	ET0 = 1;	   // Timer 0 interrupt 
	TR0 = 1;     // Start timer 0

	IT0 = 1;	   // Set external interrupt 0 It is the trigger mode of jump edge , A falling edge triggers once 
	EX0 = 1;	   // Start external interrupt 0
}

void time0() interrupt 1   // Define timer 0
{
    
	IRtime++; 			   // Detect pulse width ,1 Next is 278us
}

void int0() interrupt 0	  		// Define external interrupts 0
{
    
	static uchar i;	 			//  Declare static variables （ After jumping out of the function, the value will not be lost when it comes back to execution ）i Used for holding 33 The duration of the sub high level is stored in IRdata
	static bit startflag;		// Start storing the pulse width flag bit 
	if(startflag)	 			// Start receiving pulse width detection 
	{
    
		if( (IRtime < 53) && (IRtime >= 32) ) /* Determine whether it is a boot code , Bottom level 9000us+ high 4500us  I can count myself as 11.0592 Come on NEC The boot code of the protocol is low 8000-10000+ high 4000-5000  If the boot code has been received, then i Will not be set 0 Will start to store the pulse width in turn */
		i = 0;				 // If it is a boot code, execute i=0 Save him to IRdata The first bit of 
		IRdata[i] = IRtime;  		 // With T0 To calculate the pulse width , Save this time in the array and judge later 
		IRtime = 0;				 // Counter reset , The next falling edge is stored in the pulse width 
		i++; 					 // Count the number of times the pulse width is stored 
		if(i == 33) 				 // If deposited 34 Time   The subscript of an array is from 0 Start i be equal to 33 It means that 34 Time 
		{
    
		 	IRok = 1;				 // Then it means that the pulse width detection is completed 
			i = 0; 				 // Clear the pulse width count to prepare for the next storage 
		}
	}
	else		  
	{
    
		IRtime = 0; 				 // The pilot code starts to enter. Clear the pulse width count to start counting 
		startflag = 1;			 // Start processing flag position 1
	}
}

void IRcordpro()   				 // Extract its 33 Second pulse width for data decoding 
{
    
	uchar i, j, k, cord, value;	/*i Used for processing 4 Bytes ,j Used to process each bit in a byte ,k be used for 33 Which one of the second pulse width  cord The time used to take out the pulse width is used to judge whether it meets 1 Pulse width time */
	k = 1; 						// Take... From the first pulse width , Discard the pilot code 
	for(i = 0; i < 4; i++)
	{
    
		for(j = 0; j < 8; j++)
		{
    
			cord = IRdata[k];	    // Store the pulse width in cord
			if(cord > 5)	 		// If the pulse width is greater than me 11.0592 Of t0 The overflow rate is about 278us*5=1390 Then judge as 1
			value = value | 0x80;	/* When receiving, the lowest bit is received first ,  Put the lowest position first value The highest position is in and 0x08 Press or click   It won't change valua The value of other bits of will only make his highest position 1*/
			if(j < 7)
			{
    
				value = value >> 1;	//value Bits are shifted to the left and received in turn 8 Bit data .
			}
			k++;				// Every time the pulse width bit is added 1
		}
		IRcord[i] = value;	   // After each byte is processed, put it into IRcord Array .
		value = 0; 			   // Zero clearing value It is convenient to store data next time 
	}
	IRpro_ok = 1;				   // After receiving 4 After the bytes IRpro ok Set up 1 Indicates that infrared decoding is complete  
}

/******************* The main function **************************/ 
void main() 
{
     
	init();	// Execute initialization timer 0 And external interruptions 0
	while(1) 
	{
     
		if(IRok)    // Judge whether the pulse width is detected  
		{
       
			IRcordpro();// Decode according to the pulse width 4 Bytes of data 
			IRok = 0;	// Wait for pulse width detection again 
			if(IRpro_ok) // Determine whether the decoding is complete  
			{
    
		        switch(IRcord[2])
		   		{
    
				     case 0x45:  led = 1;			 break;  // Press "1" Light on 
				     case 0x46:  led = 0;	 		break;  // Press "2" The light goes out 
					   default:break;
		   		}
				IRpro_ok = 0;
			}
		}	
	}
} 


/******************z  Second delay function *************************/ 
void delay(unsigned int z) 
{
     
	unsigned int x,y; 
	for(x=z;x>0;x--) 
		for(y=110;y>0;y--); 
} 
/**************** Subtle delay ******************************/ 
void delay_us(unsigned int aa) 
{
     
	while(aa--); 
}

Modify the main function case The value after the statement is the key value corresponding to your remote control . as follows ：

The Baidu network disk link of the whole project is as follows ：
link ：https://pan.baidu.com/s/1VNgm2WKdiygarchKKM97Rg
Extraction code ：2022
– From Baidu network disk super member V4 The share of