funadc.c

dsp2407的函数库

/****************************************************************
*	funadc.c					See funlib.h for instuctions	*
*	Don Luebbe                  about using this file.          *
*	10/12/02                                                    *
*																*
*	This file defines three ADC functions: initADC(), getADC(), *
*	and getallADC().  initADC() initializes the ADC and should  *
*	be called before attempting to use the ADC and should be 	*
*	called only once.  											*
*																*
*	Example:	main()                                          *
*				{                                               *
*					initADC();									*
*					...                                         *
*					while(1)                                    *
*					{                                           *
*					...                                         *
*					}                                           *
*				}												*
*																*
*	getADC() accepts one desired channel to sample and returns 	*
*	the results.  It should be used when sampling only one 		*
*	channel. 													*
*																*
*	Example:	adc4 = getADC(4);								*
*				This function call samples only the ADCIN4 pin 	*
*				and place the value (between 0 - 1023) into the *
*				variable adc4.									*
*                                                               *
*	getallADC() accepts the total number of samples desired.  	*
*	It reads the global array ADCchannels[] for which channels 	*
*	are to be sampled.  It returns the results in the global 	*
*	array ADCresults[]. ADCchannels can be changed at any point *
*	in the program.  This method should be used when many 		*
*	near-simultaneous samples are desired.						*
*	                                                            *
*	Example:	ADCchannels = {5,6,2,2,0,0,...,0,0,};			*
*				getallADC(3);									*
*				adc6 = ADCresults[1];							*
*				This code will cause the ADC to sample, in 		*
*				order, channels 5-6-2-2 since the total number	*
*				of conversions is 3 + 1 = 4.  The value from	*
*				ADCIN6 is then placed in the variable adc6.		*
****************************************************************/

#include        "f2407_c.h"
#include        "funlib.h"
#include		<math.h>

int ADCchannels[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
int ADCresults[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

int initADC(void)
{
	*ADCTRL1 = 0x4000; /*reset must be done individually*/
	*ADCTRL1 = 0x1010;
	/*     
	bit 15        0:      reserved
 	bit 14        0:      reset ADC module
 	bit 13-12     10:     complete conversion before suspend
 	bit 11-8      0000:   acquisition window prescale
 	bit 7         0:      conversion clock prescale
 	bit 6         0:      continuous run
 	bit 5         0:      interrupt priority
 	bit 4         1:      cascaded mode
 	bit 3         0:      calibration enable
 	bit 2         0:      bridge enable
 	bit 1         0:      Vref select
 	bit 0         0:      self test enable
	*/

	*ADCTRL2 = 0x0000;
	/*     
	bit 15        0:      EVB SOC
 	bit 14        0:      reset sequencer1/start calibration
 	bit 13        0:      SOC sequencer
 	bit 12        0:      sequencer busy
 	bit 11-10     00:     interrupt disabled
 	bit 9         0:      interrupt flag
 	bit 8         0:      EVA disable
 	bit 7         0:      external SOC
 	bit 6         0:      reset SEQ2
 	bit 5         0:      SOC SEQ2
 	bit 4         0:      SEQ2 busy
 	bit 3-2       00:     interrupt disabled
 	bit 1         0:      interrupt flag
 	bit 0         0:      EVB disable
	*/
	
	return 0;
}

int getADC(int channel)
{   
	*MAX_CONV = 0; /* Only one conversion needed */
    
    *CHSELSEQ1 = 0x0000 | channel;

 	*ADCTRL2 = 0x4000;                 /* reset */
	*ADCTRL2 = 0x2000;                 /* SOC */
	while ((*AUTO_SEQ_SR & 0xF00)!=0); /* wait while conversion finishes */
    
 	return (*RESULT0 >> 6);
}
 	
int getallADC(int convmax)
{   
	int i = 0;

	*MAX_CONV = convmax - 1; /* Total conversions = MAX_CONV + 1 (ie 3)*/
    
    for (i = 0; i < 4; i++)
    {
    	*CHSELSEQ1 = *CHSELSEQ1 | (ADCchannels[i] << (4*i));
    }
 	
 	for (i = 0; i < 4; i++)
    {
    	*CHSELSEQ2 = *CHSELSEQ2 | (ADCchannels[(i+4)] << (4*i));
    }

 	for (i = 0; i < 4; i++)
    {
    	*CHSELSEQ3 = *CHSELSEQ3 | (ADCchannels[(i+8)] << (4*i));
    }

 	for (i = 0; i < 4; i++)
    {
    	*CHSELSEQ4 = *CHSELSEQ4 | (ADCchannels[(i+12)] << (4*i));
    }

	/*     
 	CHSELSEQ1  receives ADCchannels 0,1,2,3
 	CHSELSEQ2  receives ADCchannels 4,5,6,7
 	CHSELSEQ3  receives ADCchannels 8,9,10,11
 	CHSELSEQ4  receives ADCchannels 12,13,14,15
 	*/

 	*ADCTRL2 = 0x4000;                 /* reset */
	*ADCTRL2 = 0x2000;                 /* SOC */
	while ((*AUTO_SEQ_SR & 0xF00)!=0); /* wait while conversion finishes */

 	ADCresults[0] = (*RESULT0 >> 6);
 	ADCresults[1] = (*RESULT1 >> 6);
 	ADCresults[2] = (*RESULT2 >> 6);
 	ADCresults[3] = (*RESULT3 >> 6);
 	ADCresults[4] = (*RESULT4 >> 6);
 	ADCresults[5] = (*RESULT5 >> 6);
 	ADCresults[6] = (*RESULT6 >> 6);
 	ADCresults[7] = (*RESULT7 >> 6);
 	ADCresults[8] = (*RESULT8 >> 6);
 	ADCresults[9] = (*RESULT9 >> 6);
 	ADCresults[10] = (*RESULT10 >> 6);
 	ADCresults[11] = (*RESULT11 >> 6);
 	ADCresults[12] = (*RESULT12 >> 6);
 	ADCresults[13] = (*RESULT13 >> 6);
 	ADCresults[14] = (*RESULT14 >> 6);
 	ADCresults[15] = (*RESULT15 >> 6);
 	
 	/* Store samples into global array ADCresults */
 	
 	return 0;
}