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//*****************************************************************************

// File Name	: a2dtest.c

// 

// Title		: example usage of some avr library functions

// Revision		: 1.0

// Notes		:	

// Target MCU	: Atmel AVR series

// Editor Tabs	: 4

// 

// Revision History:

// When			Who			Description of change

// -----------	-----------	-----------------------

// 20-Oct-2002	pstang		Created the program

//*****************************************************************************

//----- 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

int main(void)

{

	u16 i,x,y;

	double fi, err, fibuf[BUFLEN];

	s16 fia, erra;

	u16 fib, errb;

	// initialize our 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

	DDRA = 0x00;

	// make sure pull-up resistors are turned off

	PORTA = 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

	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) * 180.0 / PI;		// average recorded angles and convert product to degrees

		for(i=0; i<BUFLEN; i++) err += (fibuf[i]-fi)*(fibuf[i]-fi);		// sum cubic errors

		err = sqrt(err/(BUFLEN-1))/sqrt(BUFLEN);	// compute average cubic error

		erra = floor(err);

		errb = floor((err - erra)*1000);

		fia = floor(fi);

		fib = floor((fi - fia)*1000);

		rprintf("fi:%d.%d  +- %d.%d \r\n", fia, fib, erra, errb);

	}

	return 0;

}