LUFA/Drivers/AT90USBXXX/AT90USBXXX67/ADC.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2009.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, and distribute this software
  13   and its documentation for any purpose and without fee is hereby
  14   granted, provided that the above copyright notice appear in all
  15   copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  ADC driver for the AT90USB1287, AT90USB1286, AT90USB647, AT90USB646, ATMEGA16U4 and ATMEGA32U4 AVRs.
  34  *
  35  *  \note This file should not be included directly. It is automatically included as needed by the ADC driver
  36  *        dispatch header located in LUFA/Drivers/AT90USBXXX/ADC.h.
  37  */
  38
  39 #ifndef __ADC_AT90USBXXX67_H__
  40 #define __ADC_AT90USBXXX67_H__
  41
  42         /* Includes: */
  43                 #include <avr/io.h>
  44                 #include <stdbool.h>
  45
  46                 #include "../../../Common/Common.h"
  47
  48         /* Enable C linkage for C++ Compilers: */
  49                 #if defined(__cplusplus)
  50                         extern "C" {
  51                 #endif
  52
  53         /* Preprocessor Checks: */
  54                 #if !defined(INCLUDE_FROM_ADC_H)
  55                         #error Do not include this file directly. Include LUFA/Drivers/AT90USBXXX/ADC.h instead.
  56                 #endif
  57
  58         /* Public Interface - May be used in end-application: */
  59                 /* Macros: */
  60                         /** Initializes the ADC, ready for conversions. This must be called before any other ADC operations.
  61                          *  The "mode" parameter should be a mask comprised of a conversion mode (free running or single) and
  62                          *  prescaler masks.
  63                          */
  64                         #define  ADC_Init(mode)          MACROS{ ADCSRA = ((1 << ADEN) | mode);         }MACROE
  65
  66                         /** Turns off the ADC. If this is called, any further ADC operations will require a call to the
  67                          *  ADC_Init() macro before the ADC can be used again.
  68                          */
  69                         #define  ADC_Off()               MACROS{ ADCSRA = 0;                            }MACROE
  70
  71                         /** Indicates if the ADC is enabled. This macro will return boolean true if the ADC subsystem is
  72                          *  currently enabled, or false otherwise.
  73                          */
  74                         #define  ADC_GetStatus()               ((ADCSRA & (1 << ADEN)) ? true : false)
  75
  76                         /** Indicates if the current ADC conversion is completed, or still in progress. This returns boolean
  77                          *  false if the reading is still taking place, or true if the conversion is complete and ready to be
  78                          *  read out with ADC_GetResult().
  79                          */
  80                         #define  ADC_IsReadingComplete()         (!(ADCSRA & (1 << ADSC)))
  81
  82                         /** Returns the result of the last conversion, as a 16-bit wide integer. */
  83                         #define  ADC_GetResult()                 ADC
  84
  85                         /** Reference mask, for using the voltage present at the AVR's AREF pin for the ADC reference. */
  86                         #define  ADC_REFERENCE_AREF              0
  87
  88                         /** Reference mask, for using the voltage present at the AVR's AVCC pin for the ADC reference. */
  89                         #define  ADC_REFERENCE_AVCC              (1 << REFS0)
  90
  91                         /** Reference mask, for using the internally generated 2.56V reference voltage as the ADC reference. */
  92                         #define  ADC_REFERENCE_INT2560MV         ((1 << REFS1)| (1 << REFS0))
  93
  94                         /** Left-adjusts the 10-bit ADC result, so that the upper 8 bits of the value returned by the
  95                          *  ADC_GetResult() macro contain the 8 most significant bits of the result. */
  96                         #define  ADC_LEFT_ADJUSTED               (1 << ADLAR)
  97
  98                         /** Right-adjusts the 10-bit ADC result, so that the lower 8 bits of the value returned by the
  99                          *  ADC_GetResult() macro contain the 8 least significant bits of the result. */
 100                         #define  ADC_RIGHT_ADJUSTED              (0 << ADLAR)
 101
 102                         /** Sets the ADC mode to free running, so that conversions take place continuously as fast as the ADC
 103                          *  is capable of at the given input clock speed. */
 104                         #define  ADC_FREE_RUNNING                (1 << ADATE)
 105
 106                         /** Sets the ADC mode to single conversion, so that only a single conversion will take place before
 107                          *  the ADC returns to idle. */
 108                         #define  ADC_SINGLE_CONVERSION           (0 << ADATE)
 109
 110                         /** Sets the ADC input clock to prescale by a factor of 2 the AVR's system clock. */
 111                         #define  ADC_PRESCALE_2                  (1 << ADPS0)
 112
 113                         /** Sets the ADC input clock to prescale by a factor of 4 the AVR's system clock. */
 114                         #define  ADC_PRESCALE_4                  (1 << ADPS1)
 115
 116                         /** Sets the ADC input clock to prescale by a factor of 8 the AVR's system clock. */
 117                         #define  ADC_PRESCALE_8                  ((1 << ADPS0) | (1 << ADPS1))
 118
 119                         /** Sets the ADC input clock to prescale by a factor of 16 the AVR's system clock. */
 120                         #define  ADC_PRESCALE_16                 (1 << ADPS2)
 121
 122                         /** Sets the ADC input clock to prescale by a factor of 32 the AVR's system clock. */
 123                         #define  ADC_PRESCALE_32                 ((1 << ADPS2) | (1 << ADPS0))
 124
 125                         /** Sets the ADC input clock to prescale by a factor of 64 the AVR's system clock. */
 126                         #define  ADC_PRESCALE_64                 ((1 << ADPS2) | (1 << ADPS1))
 127
 128                         /** Sets the ADC input clock to prescale by a factor of 128 the AVR's system clock. */
 129                         #define  ADC_PRESCALE_128                ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
 130
 131                 /* Inline Functions: */
 132                         /** Configures the given ADC channel, ready for ADC conversions. This function sets the
 133                          *  associated port pin as an input and disables the digital portion of the I/O to reduce
 134                          *  power consumption.
 135                          *
 136                          *  \param Channel  ADC channel number to set up for conversions
 137                          */
 138                         static inline void ADC_SetupChannel(const uint8_t Channel)
 139                         {
 140                                 DDRD  &= ~(1 << Channel);
 141                                 DIDR0 |=  (1 << Channel);
 142                         }
 143
 144                         /** Starts the reading of the given channel, but does not wait until the conversion has completed.
 145                          *  Once executed, the conversion status can be determined via the ADC_IsReadingComplete() macro and
 146                          *  the result read via the ADC_GetResult() macro.
 147                          *
 148                          *  \param MUXMask  Mask comprising of an ADC channel number, reference mask and adjustment mask
 149                          */
 150                         static inline void ADC_StartReading(const uint8_t MUXMask)
 151                         {
 152                                 ADMUX = MUXMask;
 153
 154                                 ADCSRA |= (1 << ADSC);
 155                         }
 156
 157                         /** Performs a complete single reading from channel, including a polling spinloop to wait for the
 158                          *  conversion to complete, and the returning of the converted value.
 159                          *
 160                          *  \param MUXMask  Mask comprising of an ADC channel number, reference mask and adjustment mask
 161                          */
 162                         static inline uint16_t ADC_GetChannelReading(const uint8_t MUXMask) ATTR_WARN_UNUSED_RESULT;
 163                         static inline uint16_t ADC_GetChannelReading(const uint8_t MUXMask)
 164                         {
 165                                 ADC_StartReading(MUXMask);
 166
 167                                 while (!(ADC_IsReadingComplete()));
 168
 169                                 return ADC_GetResult();
 170                         }
 171
 172         /* Disable C linkage for C++ Compilers: */
 173                 #if defined(__cplusplus)
 174                         }
 175                 #endif
 176
 177 #endif