Root at 14:06, 15 December 2011

2011-12-15T14:06:37Z

← Older revision		Revision as of 16:06, 15 December 2011
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	</syntaxhighlight>		</syntaxhighlight>

	[[category:DSP]]		[[category:DSP]][[category:Software]]

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2011-03-02T12:49:47Z

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=== Sinewave Generator Source Code ===

<syntaxhighlight lang="c">

/***********************************************************************
includes
***********************************************************************/
#include <stdint.h>
#include <math.h>

/*******************************************************************//**
defines
***********************************************************************/
#define PI 3.141592654

#define FSAMP 50000 /**< sampling frequency in Hz */
#define RES 16 /**< signal resolution in bits */
#define VOUT 2.5 /**< fullscale output voltage */

#define FSIG 1000.0 /**< sine signal frequency in Hz */
#define ASIG 2.499 /**< sine amplitude in Vpk */
#define PHSIG -PI/2.0 /**< sine phase in rad */

#define MAXLEVEL ((exp2(RES-1.0) - 1.0) / VOUT)

/*******************************************************************//**
globals
***********************************************************************/
float yn, yn_1, yn_2; /**< sinewave states */
float coeff; /**< sinewave coefficient */

volatile uint16_t DAC; /**< dummy 16-bit DAC */

/*******************************************************************//**
@brief DAC Interrupt: calculate and output sinewave

@param none
@return -
***********************************************************************/
interrupt void dac_int (void)
{
yn_2 = yn_1;
yn_1 = yn;
yn = coeff * yn_1 - yn_2;
DAC = (int16_t)(MAXLEVEL * ASIG * yn);
}

/*******************************************************************//**
@brief main program
***********************************************************************/
void main (void)
{
/*******************************************************************
local variables
*******************************************************************/
double omega;

/*******************************************************************
sinewave initialization
*******************************************************************/
omega = 2.0 * PI * FSIG/FSAMP;

yn = sin (PHSIG);
yn_1 = sin (omega + PHSIG);
coeff = 2.0 * cos (omega);

/*******************************************************************
interrupt processing
*******************************************************************/
for (;;);

}
</syntaxhighlight>

[[category:DSP]]

Sinewave Generator - Revision history

Root at 14:06, 15 December 2011

WikiImporter: Pushed from DSignT Issue Database.