avr-adc.h

MANTIS是由科罗拉多大学开发的传感器网络嵌入式操作系统。 这是mantis的0.9.5版本的源码。

//  This file is part of MANTIS OS, Operating System
//  See http://mantis.cs.colorado.edu/
//
//  Copyright (C) 2003,2004,2005 University of Colorado, Boulder
//
//  This program is free software; you can redistribute it and/or
//  modify it under the terms of the mos license (see file LICENSE)

/**
  Project Mantis
  File:   avr-adc.h
  Author: Brian Shucker
  Date:   04-14-04

  Analog-to-digital converter device driver for AtMEGA128
*/

/** @file avr-adc.h
 * @brief Implements the lowest level control of the analog to digital 
 * conversion system on the atmega128.
 * @author Jeff Rose
 * @author Modified: Brian Shucker
 * @date Created: 01/21/2003
 * @date Modified: 04/14/2004
 */

#ifndef _AVR_ADC_H_
#define _AVR_ADC_H_


#define AVR_ADC_AVERAGING_ON 1
#define AVR_ADC_AVERAGING_OFF 2
//function prototype


uint16_t rssi_poll (void);

/* ADC clock prescaler values:
   (Slower conversion is more accurate and uses less power, but the
   conversion rate (clk. freq. / prescaler) should be at least 50 khz.)
*/
#define AVR_ADC_PRESCALE_2 0x00	// Fastest
#define AVR_ADC_PRESCALE_4 0x02	
#define AVR_ADC_PRESCALE_8 0x03	
#define AVR_ADC_PRESCALE_16 0x04	
#define AVR_ADC_PRESCALE_32 0x05	
#define AVR_ADC_PRESCALE_64 0x06 // Recommended level for 4mhz clock
#define AVR_ADC_PRESCALE_128 0x07 // Slowest

#define AVR_ADC_PRESCALE_MASK 0x07 // Register mask for setting prescaler

/* ADC voltage reference:
   (Either an internal voltage reference of 2.56v or the AVCC pin)
*/
#define AVR_ADC_VREF_AVCC 0x01 // AVCC 
#define AVR_ADC_VREF_IREF 0x03 // Internal 2.56v reference

#define AVR_ADC_VREF_MASK 0xC0 // Register mask for setting vref


/* ADC channel selection:
   (Selects which input pin to use for the conversion.)
*/
#define AVR_ADC_CH_0            0x00
#define AVR_ADC_CH_1          	0x01
#define AVR_ADC_CH_2	       	0x02
#define AVR_ADC_CH_3           	0x03
#define AVR_ADC_CH_4           	0x04
#define AVR_ADC_CH_5           	0x05
#define AVR_ADC_CH_6           	0x06
#define AVR_ADC_CH_7           	0x07

#define AVR_ADC_CH_MASK         0x07

#endif