假定从8位AD中读取数据(如果是更高位的AD可定义数据类型为int),子程序为get_ad();
1、限副滤波
/* A值可根据实际情况调整
value为有效值,new_value为当前采样值
滤波程序返回有效的实际值 */
#define A 10
char value;
char filter()
{
char new_value;
new_value = get_ad();
if ( ( new_value - value > A ) || ( value - new_value > A )
return value;
return new_value;
}
2、中位值滤波法
/* N值可根据实际情况调整
排序采用冒泡法*/
#define N 11
char filter()
{
char value_buf[N];
char count,i,j,temp;
for ( count=0;count
{
value_buf[count] = get_ad();
delay();
}
for (j=0;j
{
for (i=0;i
{
if ( value_buf[i]>value_buf[i+1] )
{
temp = value_buf[i];
value_buf[i] = value_buf[i+1];
value_buf[i+1] = temp;
}
}
}
return value_buf[(N-1)/2];
}
3、算术平均滤波法
/*
*/
#define N 12
char filter()
{
int sum = 0;
for ( count=0;count
{
sum + = get_ad();
delay();
}
return (char)(sum/N);
}
4、递推平均滤波法(又称滑动平均滤波法)
/*
*/
#define N 12
char value_buf[N];
char i=0;
char filter()
{
char count;
int sum=0;
value_buf[i++] = get_ad();
if ( i == N ) i = 0;
for ( count=0;count
sum = value_buf[count];
return (char)(sum/N);
}
5、中位值平均滤波法(又称防脉冲干扰平均滤波法)
/*
*/
#define N 12
char filter()
{
char count,i,j;
char value_buf[N];
int sum=0;
for (count=0;count
{
value_buf[count] = get_ad();
delay();
}
for (j=0;j
{
for (i=0;i
{
if ( value_buf[i]>value_buf[i+1] )
{
temp = value_buf[i];
value_buf[i] = value_buf[i+1];
value_buf[i+1] = temp;
}
}
}
for(count=1;count
sum += value[count];
return (char)(sum/(N-2));
}
6、限幅平均滤波法
/*
*/
略 参考子程序1、3
7、一阶滞后滤波法
/* 为加快程序处理速度假定基数为100,a=0~100 */
#define a 50
char value;
char filter()
{
char new_value;
new_value = get_ad();
return (100-a)*value + a*new_value;
}
8、加权递推平均滤波法
/* coe数组为加权系数表,存在程序存储区。*/
#define N 12
char code coe[N] = {1,2,3,4,5,6,7,8,9,10,11,12};
char code sum_coe = 1+2+3+4+5+6+7+8+9+10+11+12;
char filter()
{
char count;
char value_buf[N];
int sum=0;
for (count=0,count
{
value_buf[count] = get_ad();
delay();
}
for (count=0,count
sum += value_buf[count]*coe[count];
return (char)(sum/sum_coe);
}
9、消抖滤波法
#define N 12
char filter()
{
char count=0;
char new_value;
new_value = get_ad();
while (value !=new_value);
{
count++;
if (count>=N) return new_value;
delay();
new_value = get_ad();
}
return value;
}
10、限幅消抖滤波法
/*
*/
略 参考子程序1、9
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