LUFA/Drivers/Peripheral/AVRU4U6U7/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/Peripheral/ADC.h.
  37  */
  38
  39 /** \ingroup Group_ADC
  40  *  @defgroup Group_ADC_AVRU4U6U7 Series U4, U6 and U7 Model ADC Driver
  41  *
  42  *  @{
  43  */
  44
  45 #ifndef __ADC_AVRU4U6U7_H__
  46 #define __ADC_AVRU4U6U7_H__
  47
  48         /* Includes: */
  49                 #include "../../../Common/Common.h"
  50
  51                 #include <avr/io.h>
  52                 #include <stdbool.h>
  53
  54         /* Enable C linkage for C++ Compilers: */
  55                 #if defined(__cplusplus)
  56                         extern "C" {
  57                 #endif
  58
  59         /* Preprocessor Checks: */
  60                 #if !defined(INCLUDE_FROM_ADC_H)
  61                         #error Do not include this file directly. Include LUFA/Drivers/Peripheral/ADC.h instead.
  62                 #endif
  63
  64         /* Public Interface - May be used in end-application: */
  65                 /* Macros: */
  66                         /** Reference mask, for using the voltage present at the AVR's AREF pin for the ADC reference. */
  67                         #define  ADC_REFERENCE_AREF              0
  68
  69                         /** Reference mask, for using the voltage present at the AVR's AVCC pin for the ADC reference. */
  70                         #define  ADC_REFERENCE_AVCC              (1 << REFS0)
  71
  72                         /** Reference mask, for using the internally generated 2.56V reference voltage as the ADC reference. */
  73                         #define  ADC_REFERENCE_INT2560MV         ((1 << REFS1)| (1 << REFS0))
  74
  75                         /** Left-adjusts the 10-bit ADC result, so that the upper 8 bits of the value returned by the
  76                          *  ADC_GetResult() macro contain the 8 most significant bits of the result. */
  77                         #define  ADC_LEFT_ADJUSTED               (1 << ADLAR)
  78
  79                         /** Right-adjusts the 10-bit ADC result, so that the lower 8 bits of the value returned by the
  80                          *  ADC_GetResult() macro contain the 8 least significant bits of the result. */
  81                         #define  ADC_RIGHT_ADJUSTED              (0 << ADLAR)
  82
  83                         /** Sets the ADC mode to free running, so that conversions take place continuously as fast as the ADC
  84                          *  is capable of at the given input clock speed. */
  85                         #define  ADC_FREE_RUNNING                (1 << ADATE)
  86
  87                         /** Sets the ADC mode to single conversion, so that only a single conversion will take place before
  88                          *  the ADC returns to idle. */
  89                         #define  ADC_SINGLE_CONVERSION           (0 << ADATE)
  90
  91                         /** Sets the ADC input clock to prescale by a factor of 2 the AVR's system clock. */
  92                         #define  ADC_PRESCALE_2                  (1 << ADPS0)
  93
  94                         /** Sets the ADC input clock to prescale by a factor of 4 the AVR's system clock. */
  95                         #define  ADC_PRESCALE_4                  (1 << ADPS1)
  96
  97                         /** Sets the ADC input clock to prescale by a factor of 8 the AVR's system clock. */
  98                         #define  ADC_PRESCALE_8                  ((1 << ADPS0) | (1 << ADPS1))
  99
 100                         /** Sets the ADC input clock to prescale by a factor of 16 the AVR's system clock. */
 101                         #define  ADC_PRESCALE_16                 (1 << ADPS2)
 102
 103                         /** Sets the ADC input clock to prescale by a factor of 32 the AVR's system clock. */
 104                         #define  ADC_PRESCALE_32                 ((1 << ADPS2) | (1 << ADPS0))
 105
 106                         /** Sets the ADC input clock to prescale by a factor of 64 the AVR's system clock. */
 107                         #define  ADC_PRESCALE_64                 ((1 << ADPS2) | (1 << ADPS1))
 108
 109                         /** Sets the ADC input clock to prescale by a factor of 128 the AVR's system clock. */
 110                         #define  ADC_PRESCALE_128                ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
 111
 112                 /* Pseudo-Function Macros: */
 113                         #if defined(__DOXYGEN__)
 114                                 /** Initializes the ADC, ready for conversions. This must be called before any other ADC operations.
 115                                  *  The "mode" parameter should be a mask comprised of a conversion mode (free running or single) and
 116                                  *  prescaler masks.
 117                                  *
 118                                  *  \param[in] Mode  Mask of ADC settings, including adjustment, prescale, mode and reference
 119                                  */
 120                                 static inline void ADC_Init(uint8_t Mode);
 121
 122                                 /** Turns off the ADC. If this is called, any further ADC operations will require a call to
 123                                  *  \ref ADC_Init() before the ADC can be used again.
 124                                  */
 125                                 static inline void ADC_ShutDown(void);
 126
 127                                 /** Indicates if the ADC is currently enabled.
 128                                  *
 129                                  *  \return Boolean true if the ADC subsystem is currently enabled, false otherwise.
 130                                  */
 131                                 static inline bool ADC_GetStatus(void);
 132
 133                                 /** Indicates if the current ADC conversion is completed, or still in progress.
 134                                  *
 135                                  *  \return Boolean false if the reading is still taking place, or true if the conversion is
 136                                  *          complete and ready to be read out with \ref ADC_GetResult()
 137                                  */
 138                                 static inline bool ADC_IsReadingComplete(void);
 139
 140                                 /** Retrieves the conversion value of the last completed ADC conversion.
 141                                  *
 142                                  *  \return The result of the last ADC conversion
 143                                  */
 144                                 static inline uint16_t ADC_GetResult(void);
 145                         #else
 146                                 #define  ADC_Init(mode)          MACROS{ ADCSRA = ((1 << ADEN) | mode);         }MACROE
 147
 148                                 #define  ADC_ShutDown()          MACROS{ ADCSRA = 0;                            }MACROE
 149
 150                                 #define  ADC_GetStatus()               ((ADCSRA & (1 << ADEN)) ? true : false)
 151
 152                                 #define  ADC_IsReadingComplete()         (!(ADCSRA & (1 << ADSC)))
 153
 154                                 #define  ADC_GetResult()                 ADC
 155                         #endif
 156
 157                 /* Inline Functions: */
 158                         /** Configures the given ADC channel, ready for ADC conversions. This function sets the
 159                          *  associated port pin as an input and disables the digital portion of the I/O to reduce
 160                          *  power consumption.
 161                          *
 162                          *  \param[in] Channel  ADC channel number to set up for conversions
 163                          */
 164                         static inline void ADC_SetupChannel(const uint8_t Channel)
 165                         {
 166                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 167                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
 168                                          defined(__AVR_ATmega32U6__))
 169                                 DDRF  &= ~(1 << Channel);
 170                                 DIDR0 |=  (1 << Channel);
 171                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 172                                 if (Channel < 8)
 173                                 {
 174                                         DDRF  &= ~(1 << Channel);
 175                                         DIDR0 |=  (1 << Channel);
 176                                 }
 177                                 else if (Channel == 8)
 178                                 {
 179                                         DDRD  &= ~(1 << 4);
 180                                         DIDR2 |=  (1 << 0);
 181                                 }
 182                                 else if (Channel < 11)
 183                                 {
 184                                         DDRD  &= ~(1 << (Channel - 3));
 185                                         DIDR2 |=  (1 << (Channel - 8));
 186                                 }
 187                                 else
 188                                 {
 189                                         DDRB  &= ~(1 << (Channel - 7));
 190                                         DIDR2 |=  (1 << (Channel - 8));
 191                                 }
 192                                 #endif
 193                         }
 194
 195                         /** Starts the reading of the given channel, but does not wait until the conversion has completed.
 196                          *  Once executed, the conversion status can be determined via the \ref ADC_IsReadingComplete() macro and
 197                          *  the result read via the \ref ADC_GetResult() macro.
 198                          *
 199                          *  \param[in] MUXMask  Mask comprising of an ADC channel number, reference mask and adjustment mask
 200                          */
 201                         static inline void ADC_StartReading(const uint8_t MUXMask)
 202                         {
 203                                 ADMUX = MUXMask;
 204
 205                                 ADCSRA |= (1 << ADSC);
 206                         }
 207
 208                         /** Performs a complete single reading from channel, including a polling spin-loop to wait for the
 209                          *  conversion to complete, and the returning of the converted value.
 210                          *
 211                          *  \param[in] MUXMask  Mask comprising of an ADC channel number, reference mask and adjustment mask
 212                          */
 213                         static inline uint16_t ADC_GetChannelReading(const uint8_t MUXMask) ATTR_WARN_UNUSED_RESULT;
 214                         static inline uint16_t ADC_GetChannelReading(const uint8_t MUXMask)
 215                         {
 216                                 ADC_StartReading(MUXMask);
 217
 218                                 while (!(ADC_IsReadingComplete()));
 219
 220                                 return ADC_GetResult();
 221                         }
 222
 223         /* Disable C linkage for C++ Compilers: */
 224                 #if defined(__cplusplus)
 225                         }
 226                 #endif
 227
 228 #endif
 229
 230 /** @} */