hal_adconversion.c

Porting of RF Blinking LED Software Example to CC2420 -MSP430文档及源代码

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 *      ***   +++   ***                                                      *
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 *      ***   +                            CHIPCON CC2420                    *
 *      ***   + +   ***             	CC2420 HAL LIBRARY FILE              *
 *      ***   +++   ***                                                      *
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 *       																     *
 * A number of helpful library macros and defines for the ATmega128          *
 * to be included to increase the legibility of your code and to be used     *
 * with CC2420DB.                                                            *
 *                                                                           *
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 * Device:      CC2420                                                       *
 * File:		hal_ADConversion.h					                         *            
 * Author:		MBR						                                     *
 * Target:		ATmega128						                             *
 * Created:		2004-02-11					                                 *
 *				    			                                             *
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 * Revision history:                                                         *
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#include <include.h>

// Global SPI status byte from CC2420
BYTE spiStatusByte;
//----------------------------------------------------------------------------
//  INT16 hal_ADConversion(void)
//
//  Description:
//      This function perfroms eight ADC conversions and establishes an
//      average ADC value found by the internal Atmega128 ADC.
//
//  Arguments:
//     None
//     
//  Return value:
//      The ADC value found for the ADC conversion preformed
//----------------------------------------------------------------------------
INT16 hal_ADConversion(void) {
	
	INT16 ADC_temp;
	INT16 hadcresult;
	UINT8 i;
	    
	//Do the ADC conversion 8 times for better accuracy    
	for(i = 0; i < 8; i++) {	
		//Start conversion				 
		ADCSRA |= (1 << ADSC);				
		//Wait for conversion done, ADIF flag active	
        while(!(ADCSRA & 0x10));			
		//Read out ADCL register
		ADC_temp = ADCL;            		
		//Read out ADCH register 		
		ADC_temp += (ADCH << 8);    		       
		//Accumulate result (8 samples) for later averaging
		hadcresult += ADC_temp;      		
	}
    // Average the 8 samples
    hadcresult = hadcresult >> 3;     		
    // Return the ADC value found
	return(hadcresult);
} // hal_ADConversion