Lab 15/HW 15

Lab 15 (DC Motor + Potentiometer)

//Simple Motor Speed Control Program
const int MOTOR=9; //Motor on Digital Pin 9
const int POT = A0;
void setup()
{
 pinMode (MOTOR, OUTPUT);
}
void loop()
{
 int val = analogRead(A0);
 analogWrite(MOTOR, val);
}

HW 15( Seismic Data):

#include <stdio.h>
#define FILENAME "seismic1.txt"
#define MAX_SIZE 1000
//#define THRESHOLD 1.5

int main(void)
{
/* Declare variables and function prototypes. */
int k, npts, short_window, long_window, count = 1, num_events = 0;
float threshold;
double sensor[MAX_SIZE], time_incr, short_power,
long_power, ratio;
FILE *file_ptr;
double power_w(double *ptr,int n);

/* Read sensor data file. */
file_ptr = fopen(FILENAME,"r");
if (file_ptr == NULL)
printf("Error opening input file. \n");
else
{
fscanf(file_ptr,"%d %lf",&npts,&time_incr);
if (npts > MAX_SIZE)
printf("Data file too large for array. \n");
else
{
/* Read data into an array. */
for (k=0; k<=npts-1; k++)
fscanf(file_ptr,"%lf",&sensor[k]);
/* Read window sizes from the keyboard. */
printf("Enter number of points for short window: \n");
scanf("%d",&short_window);
printf("Enter number of points for long window: \n");
scanf("%d",&long_window);
printf("Enter Threshold value: \n");
scanf("%f",&threshold);
/* Compute power ratios and search for events. */
while (threshold <= 1)
{
printf("Threshold must be greater than 1, enter another value:\n");
scanf("%f",&threshold); 
} 
for (k=long_window-1; k<=npts-1; k++)
{
short_power = power_w(&sensor[k],short_window);
long_power = power_w(&sensor[k],long_window);
ratio = short_power/long_power;
if (ratio > threshold)
{
printf("Possible event at %f seconds \n",time_incr*k);
num_events += count;
}
}

/* Close file. */
fclose(file_ptr);
}
printf("Number of events: %d \n", num_events); 
}
return 0;
}

/* This function computes the average power in a specified */
/* window of a double array. */

double power_w(double *ptr, int n)
{
/* Declare and initialize variables. */
int k;
double xsquare=0;
/* Compute sum of values squared in the array x. */
for (k=0; k<=n-1; k++)
xsquare += *(ptr-k)*(*(ptr-k));
/* Return the average squared value. */
return xsquare/n;
}