PIC16F15323单片机 （ADC）--汇编+C语言

1 基本原理

1.1 寄存器介绍

1.2 寄存器汇总

1.3 ADC采集实现框图

2 实现代码

/*---------------------------------函数功能：-------------------------------------
 RA0(AN0)作为外部模拟电压的模拟输入口，并且用RC0口（LED）来判断电压采集是否完成，
 如果AD采集完成，则AD对应的标志位ADIF=1，如果使能有效，则会产生一个中断，此时LED灯亮。
 
 编程思路：参考手册的P131  To do an A/D Conversion, follow these steps
----------------------------------------------------------------------------*/


// PIC16F15323 Configuration Bit Settings

// 'C' source line config statements

// CONFIG1
#pragma config FEXTOSC = ECH    // External Oscillator mode selection bits (EC above 8MHz; PFM set to high power)
#pragma config RSTOSC = EXT1X   // Power-up default value for COSC bits (EXTOSC operating per FEXTOSC bits)
#pragma config CLKOUTEN = OFF   // Clock Out Enable bit (CLKOUT function is disabled; i/o or oscillator function on OSC2)
#pragma config CSWEN = ON       // Clock Switch Enable bit (Writing to NOSC and NDIV is allowed)
#pragma config FCMEN = ON       // Fail-Safe Clock Monitor Enable bit (FSCM timer enabled)

// CONFIG2
#pragma config MCLRE = ON       // Master Clear Enable bit (MCLR pin is Master Clear function)
#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)
#pragma config LPBOREN = OFF    // Low-Power BOR enable bit (ULPBOR disabled)
#pragma config BOREN = ON       // Brown-out reset enable bits (Brown-out Reset Enabled, SBOREN bit is ignored)
#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (VBOR) set to 1.9V on LF, and 2.45V on F Devices)
#pragma config ZCD = OFF        // Zero-cross detect disable (Zero-cross detect circuit is disabled at POR.)
#pragma config PPS1WAY = ON     // Peripheral Pin Select one-way control (The PPSLOCK bit can be cleared and set only once in software)
#pragma config STVREN = ON      // Stack Overflow/Underflow Reset Enable bit (Stack Overflow or Underflow will cause a reset)

// CONFIG3
#pragma config WDTCPS = WDTCPS_31// WDT Period Select bits (Divider ratio 1:65536; software control of WDTPS)
#pragma config WDTE = ON        // WDT operating mode (WDT enabled regardless of sleep; SWDTEN ignored)
#pragma config WDTCWS = WDTCWS_7// WDT Window Select bits (window always open (100%); software control; keyed access not required)
#pragma config WDTCCS = SC      // WDT input clock selector (Software Control)

// CONFIG4
#pragma config BBSIZE = BB512   // Boot Block Size Selection bits (512 words boot block size)
#pragma config BBEN = OFF       // Boot Block Enable bit (Boot Block disabled)
#pragma config SAFEN = OFF      // SAF Enable bit (SAF disabled)
#pragma config WRTAPP = OFF     // Application Block Write Protection bit (Application Block not write protected)
#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot Block not write protected)
#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration Register not write protected)
#pragma config WRTSAF = OFF     // Storage Area Flash Write Protection bit (SAF not write protected)
#pragma config LVP = ON         // Low Voltage Programming Enable bit (Low Voltage programming enabled. MCLR/Vpp pin function is MCLR.)

// CONFIG5
#pragma config CP = OFF         // UserNVM Program memory code protection bit (UserNVM code protection disabled)

// #pragma config statements should precede project file includes.
// Use project enums instead of #define for ON and OFF.

#include <xc.h>// 调用PIC16f15323单片机的头文件
//#include"delay.h"//调用延时子函数的头文件




/*-----------宏定义--------------*/
#define  uint  unsigned int
#define  uchar unsigned char

uint  ADbuf=0;						// 缓存AD转换结果


/*-----------子函数声明--------------*/



/*-----------主函数--------------*/
void main()
{
    //-------------------1、Configure Port:---------------------//
	// The corresponding data direction register is TRISA. 
	// Setting  a TRISA bit (= 1) will make the corresponding PORTA pi an input. 
	// Clearing a TRISA bit (= 0) will make the corresponding PORTA pin an output.

	// 解释为什么需要TRISA0=1？ After the A/D module has been configured as desired, 
	// the selected channel must be acquired before the conversion is started. 
	// The analog input channels must have their corresponding TRIS bits selected as inputs. 
	TRISA0=1;					// RA0口为输入口，电压输入口	
    TRISC0=0;					// AD响应中断对应的LED灯的数据方向为输出
		
	// 1 = Port pin is > VIH，即高电平  ;  0 = Port pin is < VIL，即低电平
	RA0=0;						// 要不要这行语句没有影响，因为该端口是输入端口
	RC0=0;						// LED灯的初值为灭
				
    //The ANSELA register (Register 14-4) is used to configure the Input mode of an I/O pin to analog.
    // Setting the appropriate ANSE     如果ANSEL=1，IO口为模拟输入，如果ANSEL=0，数字IO口。
    ANSA0=1;                    // Set RA0 to analog  ANSELA0,为什么见头文件<xc.h>

    
	while(1)					// 死循环，单片机初始化后，就一直运行这个死循环
	{
        //-------------------2、Configure the ADC module:---------------------//
        //（1）寄存器ADCON1: ADFM ADCS<2:0> - - ADPREF<1:0>
    
        // 10-BIT ADC CONVERSION RESULT FORMAT 
        ADFM=1;					//  AD Result Format Select bit.  0 = Left justified.  1 = Right justified	
                
        //The source of the conversion clock is software selectable via the ADCS<2:0> bits 
        ADCS2=0;ADCS1=0;ADCS0=0;		// Select ADC conversion clock    FOSC/2
           
         // The ADPREF<1:0> bits of the ADCON1 register provides control of the positive voltage reference
        ADPREF1=0;ADPREF0=0;            // Select voltage reference  00 =VREF+ is connected to VDD
        
        
        //（2）寄存器ADCON0:  CHS<5:0> GO/DONE ADON
               
        //The CHS<5:0> bits of the ADCON0 register determine which channel is connected to the sample and hold circuit.
        //CHS5=1;CHS4=1;CHS3=1;CHS2=1;CHS1=0;CHS0=0;   // Select ADC input channel  Temperature sensor  选择温度传感器作为模拟输入
        CHS5=0;CHS4=0;CHS3=0;CHS2=0;CHS1=0;CHS0=0;   //   Select ADC input channel   选择RA0(AN0)作为模拟输入
        
             
        //ADC Conversion Status bit. 1 = ADC conversion cycle in progress. Setting this bit starts an ADC conversion cycle.
        // This bit is automatically cleared by hardware when the ADC conversion has completed.
        // 0 = ADC conversion completed/not in progress
        GOnDONE=0;				// AD Conversion Status bit。为什么叫用GO_DONE看一下xc.h头文件
               
        //To enable the ADC module, the ADON bit of the ADCON0 register must be set to a ‘1’. 
        ADON=1;					//Turn on ADC module    模数转换器使能位。 1 = A/D converter module is powered up  
        
        
        
		 //--------------------3、Configure ADC interrupt (optional):---------------------//
		//ADIE=0;				//禁止AD中断
		//AD中断使能
		ADIE=1;
		ADIF=0;					// Clear ADIF bit 
        INTEDG=1;               // Interrupt Edge Select bit   1 = Interrupt on rising edge of INT pin
		PEIE=1;					// 允许外设中断       
		GIE=1;					// 总中断允许
      
        
        
        //----------ADC BLOCK DIAGRAM框图有下面两个寄存器，但是AD采集程序没有用到？--------------//
        // AUTO CONVERSION TRIGGER    
        // TRIGSEL<3:0>;
        
        
        //The Auto-conversion Trigger source is selected with the ADACT<4:0> bits of the ADACT register.
        ADACT4=0;ADACT3=0;ADACT2=0;ADACT1=0;ADACT0=0;//Auto-Conversion Trigger Selection bits
        
        
        
        //--------------------4、 Wait the required acquisition time:---------------------//
      	asm("NOP");				//延时，让模拟电压稳定
		asm("NOP");
		asm("NOP");
		asm("NOP");
		asm("NOP");  
        
        
        
        //---------------5、Start conversion by setting the GO/DONE bit.:---------------------//
        // When ADON = 1时，GO_DONE=1: AD conversion in progress set this bit（GO_DONE=1）, starts the AD conversion. 
		// it is automatically cleared by hardware when the AD conversion is complete
		 GOnDONE=1;				//开始进行AD转换   GO/DONE: A/D Conversion Status bit  ADGO=1;
         
         
        
        //---------6、Wait for ADC conversion to complete by one ofthe following:（1）Polling the GO/DONE bit。（2）Waiting for the ADC interrupt------//
		while( GOnDONE) continue;//等待AD转换结束，AD转换完成后，GO_DONE自动由1变成0   
        
         
         
        //-----------------------7、Read ADC Result----------------------//
       	// The conversion of an analog input signal results in a corresponding 10-bit digital number. 
		// The ADRESH（高8位）:ADRESL（低8位） registers contain the 10-bit result of the AD conversion.
		// When the AD conversion is complete, the result is loaded into this AD Result register pair, 
		// and the GO/DONE bit is cleared and the A/D interrupt flag bit ADIF is set
         // 需要注意到底是左对齐还是右对齐，这会影响ADbuf=ADRESH*256+ADRESL是否正确
		ADbuf=ADRESH*256+ADRESL;//转换结果一共有10bit。由于2^10为1024，所以这是一个4位数  0-1023 
        
        
        
        //---------------8、Clear the ADC interrupt flag (required if interrupt is enabled)--------------------//
        
            
	}
	
}



/*************中断服务程序***************/
// void __interrupt(irq(TMR0,TMR1),base(0x100)) timerIsr(void)
// 文档里可以查到要用 void __interrupt() ISR(void) 的形式添加中断程序
//void interrupt ISR(void)//PIC单片机的所有中断都是这样一个入口
void __interrupt() ISR(void)//PIC单片机的所有中断都是这样一个入口
{
	// When the AD conversion is complete, the A/D interrupt flag bit ADIF is set. 
	if(ADIF==1)					// 需要进一步判断是否为外部中断的溢出中断标志位    
	{
		// The interrupt flag bit(s) must be cleared in software before 
		// re-enabling interrupts to avoid recursive interrupts
		//溢出中断标志位清零     如果ADIF出现上升沿，则产生中断，所以中断发生之后要清零。
		ADIF=0;			

		

		// 执行中断处理程序，执行中断产生时想要执行的功能
		RC0=1;				// 外部中断发生时，LED灯亮

	}
}



/***********************************汇编语言**********************************/
/*
BANKSEL ADCON1 ;              //选择寄存器ADCON1
MOVLW B’11110000’;          //将立即数11110000传送给工作寄存器W  功能：Right justify, ADCRC,oscillator; Vdd and Vss Vref
MOVWF ADCON1 ;                //将W内的数据传送给ADCON1寄存器    

BANKSEL TRISA ;                 //选择寄存器TRISA
BSF TRISA,0 ;                   //将TRISA第0位置1，即将端口RA0设置为输入  功能：Set RA0 to input
 
BANKSEL ANSELA ;                //选择寄存器ANSELA
BSF ANSELA,0 ;                  //将ANSLA的第0位置1，即将端口RA0设置为模拟输入   功能：Set RA0 to analog

BANKSEL ADCON0 ;                //选择寄存器ADCON0
MOVLW B’00000001’ ;           //将立即数00000001传送给工作寄存器W    功能：Select channel AN0;ADC conversion cycle in progress. ；  ADC is enabled
MOVWF ADCON0 ;                  //将W内的数据传送给ADCON0寄存器

CALL SampleTime ;               // 延时 Acquisiton delay

BSF ADCON0,ADGO ;               //将ADCON0的ADGO位置1，开始转换  功能：Start conversion   ADC Conversion Status bit。1 = ADC conversion cycle in progress.

BTFSC ADCON0,ADGO ;             //Is conversion done? 判断ADCON0的GO位是否为0?  为0则跳过，为1则顺序执行；
GOTO $-1 ;                      // No, test again   没有转换完成，再检测一遍

BANKSEL ADRESH ;                //选择寄存器ADRESH
MOVF ADRESH,W ;                 // Read upper 2 bits  将高位ADRESH的数据存入W寄存器中
MOVWF RESULTHI ;                //store in GPR space  将数据存储
 
BANKSEL ADRESL ;                //选择寄存器ADRESL
MOVF ADRESL,W ;                 //Read lower 8 bits
MOVWF RESULTLO ;                //Store in GPR space

*/