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//----- Include Files ---------------------------------------------------------
#include <avr/io.h> // include I/O definitions (port names, pin names, etc)
#include <avr/interrupt.h> // include interrupt support
#include <math.h>
#include "global.h" // include our global settings
#include "uart2.h" // include uart function library
#include "rprintf.h" // include printf function library
#include "timer.h" // include timer function library (timing, PWM, etc)
#include "a2d.h" // include A/D converter function library
//----- Begin Code ------------------------------------------------------------
#define BUFLEN 64
void radtodeg(double fi, u16 *deg, u08 *min, u08 *sec) //convert radians to degrees mins and seconds
{
double pom;
fi=fi*180/PI;
*deg=(u16)trunc(fi);
pom=(fi-(*deg))*60;
*min=(u08)trunc(pom);
*sec=(u08)round((pom-(*min))*60);
}
inline double quadraticerror(double average, double buf[], u16 size) // compute average quadratic error
{
u16 i;
double err=0;
for(i=0; i<size; i++) err += square(buf[i]-average); // sum quadratic errors
err = sqrt((1/(double)size)*err);
return err;
}
int main(void)
{
u16 i,x,y;
double fi, err, fibuf[BUFLEN]; // buffer for recorded and computed values
u08 fi_min, fi_sec, err_min, err_sec; // computed angles
u16 fi_deg, err_deg; // computed angles in whole degrees
// initialize some libraries
// initialize the UART (serial port)
uartInit();
uartSetBaudRate(0,9600);
// make all rprintf statements use uart for output
rprintfInit(uart0SendByte);
// initialize the timer system
timerInit();
// turn on and initialize A/D converter
a2dInit();
// configure a2d port (PORTA) as input
// so we can receive analog signals
DDRF = 0x00;
// make sure pull-up resistors are turned off
PORTF = 0x00;
// set the a2d prescaler (clock division ratio)
// - a lower prescale setting will make the a2d converter go faster
// - a higher setting will make it go slower but the measurements
// will be more accurate
// - other allowed prescale values can be found in a2d.h
a2dSetPrescaler(ADC_PRESCALE_DIV128);
// set the a2d reference
// - the reference is the voltage against which a2d measurements are made
// - other allowed reference values can be found in a2d.h
a2dSetReference(ADC_REFERENCE_AREF);
// use a2dConvert8bit(channel#) to get an 8bit a2d reading
// use a2dConvert10bit(channel#) to get a 10bit a2d reading
rprintf("inklinometr 2009\r\n");
while(1)
{
fi=0;
err=0;
for(i=0; i<BUFLEN; i++)
{
x = a2dConvert10bit(ADC_CH_ADC0);
y = a2dConvert10bit(ADC_CH_ADC1);
fibuf[i] = atan2((double)x-511,(double)y-511); // record computed angles to buffer for post processing
}
for(i=0; i<BUFLEN; i++) fi += fibuf[i]; // sum recorded angles
fi = (fi/BUFLEN)+PI; // average recorded angles and expand product to whole circle
err=quadraticerror((fi-PI),fibuf,BUFLEN);
radtodeg(fi,&fi_deg,&fi_min,&fi_sec); //translate radians to degrees
radtodeg(err,&err_deg,&err_min,&err_sec);
rprintf("fi:%d.%d.%d +- %d.%d.%d \r\n", fi_deg, fi_min, fi_sec, err_deg, err_min, err_sec);
delay_ms(20);
}
return 0;
}