1 /************************************************************
 2 **FileName: ADC.c
 3 **Author:   cm     Version :  V1.0      Date: 2017-4-16
 4 **Chip:         dsPIC33FJ256GP710
 5 **Description:          ADC    
 6 **              工作频率FCY=40M 
 7 **              使用外部XT 应定义XT_PLL  
 8 **Function List:  
 9 **                 
10 ***********************************************************/
11 #include "ADC.h"
12 #include "Delay.h"
13 #define N 7
14 void Init_ADC()
15 {
16     _TRISB0=1;                                //端口引脚定义
17     _TRISB1=1;
18     _TRISB2=1;
19     _TRISB3=1;
20     _TRISA9=1;
21     _TRISA10=1;
22     AD1CON1bits.ADON=0;                        //禁止ADC
23     AD1CON1bits.AD12B=0;                    //选择10位模式
24     AD1CON2bits.VCFG=0B011;                    //参考电压选择外部Vref+和外部Vref-
25     AD1CON3bits.ADCS=0X02;                    //选择模拟转换时钟
26     AD1CON3bits.ADRC=0;                        //选择内部时钟
27     AD1PCFGH=0XFFFF;                        //选择AN0引脚作为模拟输入
28     AD1PCFGL=0XFFF0;                        
29     AD1CHS0=0X0000;                            //确定如何将输入分配给采样保持通道
30     AD1CON2bits.CHPS=0B00;                    //使用的通道为CH0
31     AD1CON1bits.SIMSAM=0;                    //按顺序依次单独采样多个通道中每个通道
32     AD1CSSL=0X0003;                            //对AN0进行扫描
33     AD1CON1bits.SAMP=0;                        //手动采样
34     AD1CON1bits.FORM=0B00;                    //缓冲区的存储方式输出格式为整数
35     AD1CON4=0X0004;                            //给每个模拟输入分配16字的缓冲区
36     AD1CON1bits.ADON=1;                        //开启ADC
37 }
38 
39 unsigned int ADC(unsigned int input)
40 {
41     static unsigned int AD=0;
42     AD1CHS0=input;
43     AD1CON1bits.SAMP=1;                        //收到采样
44     DelayUs(1);                            //延时等待
45     AD1CON1bits.SAMP=0;                        //开始装换
46     while(!AD1CON1bits.DONE);                
47     AD=ADC1BUF0;                            //取值
48     return AD;
49 }
50 
51 unsigned int filter(unsigned int ANx)
52 {
53     unsigned int sum,AD_value,i;
54     for(i=0;i<20;i++)
55     {
56     sum=ADC(ANx)+sum;
57     }
58     AD_value=http://www.mamicode.com/sum/20;
59     sum=0;
60     return AD_value;
61 }
62 
63 unsigned int filter1(unsigned int ANx)
64 {
65     
66     unsigned int AD_temp;
67     unsigned int value_buf[N];
68     unsigned char count,i,j;
69     for ( count=0;count<N;count++)
70     {
71         value_buf[count]=ADC(ANx);
72         DelayMs(1);
73     }
74     for (j=0;j<N-1;j++)
75     {
76         for (i=0;i<N-j;i++)
77         {
78             if ( value_buf[i]>value_buf[i+1] )
79             {
80                 AD_temp = value_buf[i];
81                 value_buf[i]= value_buf[i+1];
82                 value_buf[i+1] = AD_temp;
83             }
84         }
85     }
86     return value_buf[(N-1)/2];
87 }
88 unsigned int filter2(unsigned int ANx)
89 {
90     unsigned int sum,AD_value,i;
91     for(i=0;i<5;i++)
92     {
93     sum=filter1(ANx)+sum;
94     }
95     AD_value=http://www.mamicode.com/sum/5;
96     sum=0;
97     return AD_value;
98 }