LUFA/Drivers/Peripheral/AVR8/ADC.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all 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 8-Bit AVRs containing a hardware ADC module.
  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_AVR8 8-Bit AVR ADC Driver
  41  *
  42  *  ADC driver for 8-Bit AVRs containing a hardware ADC module.
  43  *
  44  *  \note This file should not be included directly. It is automatically included as needed by the ADC driver
  45  *        dispatch header located in LUFA/Drivers/Peripheral/ADC.h.
  46  *
  47  *  @{
  48  */
  49
  50 #ifndef __ADC_AVR8_H__
  51 #define __ADC_AVR8_H__
  52
  53         /* Includes: */
  54                 #include "../../../Common/Common.h"
  55
  56                 #include <avr/io.h>
  57                 #include <stdbool.h>
  58
  59         /* Enable C linkage for C++ Compilers: */
  60                 #if defined(__cplusplus)
  61                         extern "C" {
  62                 #endif
  63
  64         /* Preprocessor Checks: */
  65                 #if !defined(__INCLUDE_FROM_ADC_H)
  66                         #error Do not include this file directly. Include LUFA/Drivers/Peripheral/ADC.h instead.
  67                 #endif
  68
  69         /* Public Interface - May be used in end-application: */
  70                 /* Macros: */
  71                         /** Reference mask, for using the voltage present at the AVR's AREF pin for the ADC reference. */
  72                         #define  ADC_REFERENCE_AREF              0
  73
  74                         /** Reference mask, for using the voltage present at the AVR's AVCC pin for the ADC reference. */
  75                         #define  ADC_REFERENCE_AVCC              (1 << REFS0)
  76
  77                         /** Reference mask, for using the internally generated 2.56V reference voltage as the ADC reference. */
  78                         #define  ADC_REFERENCE_INT2560MV         ((1 << REFS1)| (1 << REFS0))
  79
  80                         /** Left-adjusts the 10-bit ADC result, so that the upper 8 bits of the value returned by the
  81                          *  ADC_GetResult() macro contain the 8 most significant bits of the result. */
  82                         #define  ADC_LEFT_ADJUSTED               (1 << ADLAR)
  83
  84                         /** Right-adjusts the 10-bit ADC result, so that the lower 8 bits of the value returned by the
  85                          *  ADC_GetResult() macro contain the 8 least significant bits of the result. */
  86                         #define  ADC_RIGHT_ADJUSTED              (0 << ADLAR)
  87
  88                         /** Sets the ADC mode to free running, so that conversions take place continuously as fast as the ADC
  89                          *  is capable of at the given input clock speed. */
  90                         #define  ADC_FREE_RUNNING                (1 << ADATE)
  91
  92                         /** Sets the ADC mode to single conversion, so that only a single conversion will take place before
  93                          *  the ADC returns to idle. */
  94                         #define  ADC_SINGLE_CONVERSION           (0 << ADATE)
  95
  96                         /** Sets the ADC input clock to prescale by a factor of 2 the AVR's system clock. */
  97                         #define  ADC_PRESCALE_2                  (1 << ADPS0)
  98
  99                         /** Sets the ADC input clock to prescale by a factor of 4 the AVR's system clock. */
 100                         #define  ADC_PRESCALE_4                  (1 << ADPS1)
 101
 102                         /** Sets the ADC input clock to prescale by a factor of 8 the AVR's system clock. */
 103                         #define  ADC_PRESCALE_8                  ((1 << ADPS0) | (1 << ADPS1))
 104
 105                         /** Sets the ADC input clock to prescale by a factor of 16 the AVR's system clock. */
 106                         #define  ADC_PRESCALE_16                 (1 << ADPS2)
 107
 108                         /** Sets the ADC input clock to prescale by a factor of 32 the AVR's system clock. */
 109                         #define  ADC_PRESCALE_32                 ((1 << ADPS2) | (1 << ADPS0))
 110
 111                         /** Sets the ADC input clock to prescale by a factor of 64 the AVR's system clock. */
 112                         #define  ADC_PRESCALE_64                 ((1 << ADPS2) | (1 << ADPS1))
 113
 114                         /** Sets the ADC input clock to prescale by a factor of 128 the AVR's system clock. */
 115                         #define  ADC_PRESCALE_128                ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
 116
 117                         //@{
 118                         /** MUX mask define for the ADC0 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 119                         #define  ADC_CHANNEL0                    0x00
 120
 121                         /** MUX mask define for the ADC1 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 122                         #define  ADC_CHANNEL1                    0x01
 123
 124                         #if !(defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 125                                 /** MUX mask define for the ADC2 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 126                                  *
 127                                  *  \note Note available on all AVR models.
 128                                  */
 129                                 #define  ADC_CHANNEL2                    0x02
 130
 131                                 /** MUX mask define for the ADC3 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 132                                  *
 133                                  *  \note Note available on all AVR models.
 134                                  */
 135                                 #define  ADC_CHANNEL3                    0x03
 136                         #endif
 137
 138                         /** MUX mask define for the ADC4 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 139                         #define  ADC_CHANNEL4                    0x04
 140
 141                         /** MUX mask define for the ADC5 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 142                         #define  ADC_CHANNEL5                    0x05
 143
 144                         /** MUX mask define for the ADC6 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 145                         #define  ADC_CHANNEL6                    0x06
 146
 147                         /** MUX mask define for the ADC7 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 148                         #define  ADC_CHANNEL7                    0x07
 149
 150                         /** MUX mask define for the internal 1.1V bandgap channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 151                         #define  ADC_1100MV_BANDGAP              0x1E
 152
 153                         #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 154                                 /** MUX mask define for the ADC8 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 155                                  *
 156                                  *  \note Note available on all AVR models.
 157                                  */
 158                                 #define  ADC_CHANNEL8                0x20
 159
 160                                 /** MUX mask define for the ADC9 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 161                                  *
 162                                  *  \note Note available on all AVR models.
 163                                  */
 164                                 #define  ADC_CHANNEL9                0x21
 165
 166                                 /** MUX mask define for the ADC10 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 167                                  *
 168                                  *  \note Note available on all AVR models.
 169                                  */
 170                                 #define  ADC_CHANNEL10               0x22
 171
 172                                 /** MUX mask define for the ADC11 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 173                                  *
 174                                  *  \note Note available on all AVR models.
 175                                  */
 176                                 #define  ADC_CHANNEL11               0x23
 177
 178                                 /** MUX mask define for the ADC12 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 179                                  *
 180                                  *  \note Note available on all AVR models.
 181                                  */
 182                                 #define  ADC_CHANNEL12               0x24
 183
 184                                 /** MUX mask define for the ADC13 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 185                                  *
 186                                  *  \note Note available on all AVR models.
 187                                  */
 188                                 #define  ADC_CHANNEL13               0x25
 189
 190                                 /** MUX mask define for the internal temperature sensor channel of the ADC. See \ref ADC_StartReading and
 191                                  *  \ref ADC_GetChannelReading.
 192                                  *
 193                                  *  \note Note available on all AVR models.
 194                                  */
 195                                 #define  ADC_INT_TEMP_SENS           0x27
 196                         #endif
 197                         //@}
 198
 199                 /* Pseudo-Function Macros: */
 200                         #if defined(__DOXYGEN__)
 201                                 /** Initializes the ADC, ready for conversions. This must be called before any other ADC operations.
 202                                  *  The "mode" parameter should be a mask comprised of a conversion mode (free running or single) and
 203                                  *  prescaler masks.
 204                                  *
 205                                  *  \param[in] Mode  Mask of ADC settings, including adjustment, prescale, mode and reference
 206                                  */
 207                                 static inline void ADC_Init(uint8_t Mode);
 208
 209                                 /** Turns off the ADC. If this is called, any further ADC operations will require a call to
 210                                  *  \ref ADC_Init() before the ADC can be used again.
 211                                  */
 212                                 static inline void ADC_ShutDown(void);
 213
 214                                 /** Indicates if the ADC is currently enabled.
 215                                  *
 216                                  *  \return Boolean true if the ADC subsystem is currently enabled, false otherwise.
 217                                  */
 218                                 static inline bool ADC_GetStatus(void);
 219
 220                                 /** Indicates if the current ADC conversion is completed, or still in progress.
 221                                  *
 222                                  *  \return Boolean false if the reading is still taking place, or true if the conversion is
 223                                  *          complete and ready to be read out with \ref ADC_GetResult()
 224                                  */
 225                                 static inline bool ADC_IsReadingComplete(void);
 226
 227                                 /** Retrieves the conversion value of the last completed ADC conversion.
 228                                  *
 229                                  *  \return The result of the last ADC conversion
 230                                  */
 231                                 static inline uint16_t ADC_GetResult(void);
 232                         #else
 233                                 #define  ADC_Init(mode)          MACROS{ ADCSRA = ((1 << ADEN) | mode);         }MACROE
 234
 235                                 #define  ADC_ShutDown()          MACROS{ ADCSRA = 0;                            }MACROE
 236
 237                                 #define  ADC_GetStatus()               ((ADCSRA & (1 << ADEN)) ? true : false)
 238
 239                                 #define  ADC_IsReadingComplete()        (ADCSRA & (1 << ADSC))
 240
 241                                 #define  ADC_GetResult()                 ADC
 242                         #endif
 243
 244                 /* Inline Functions: */
 245                         /** Configures the given ADC channel, ready for ADC conversions. This function sets the
 246                          *  associated port pin as an input and disables the digital portion of the I/O to reduce
 247                          *  power consumption.
 248                          *
 249                          *  \note This must only be called for ADC channels with are connected to a physical port
 250                          *        pin of the AVR, denoted by its special alternative function ADCx.
 251                          *
 252                          *  \note The channel number must be specified as an integer, and NOT a ADC_CHANNELx mask.
 253                          *
 254                          *  \param[in] Channel  ADC channel number to set up for conversions
 255                          */
 256                         static inline void ADC_SetupChannel(const uint8_t Channel)
 257                         {
 258                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 259                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
 260                                          defined(__AVR_ATmega32U6__))
 261                                 DDRF  &= ~(1 << Channel);
 262                                 DIDR0 |=  (1 << Channel);
 263                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 264                                 if (Channel < 8)
 265                                 {
 266                                         DDRF  &= ~(1 << Channel);
 267                                         DIDR0 |=  (1 << Channel);
 268                                 }
 269                                 else if (Channel == 8)
 270                                 {
 271                                         DDRD  &= ~(1 << 4);
 272                                         DIDR2 |=  (1 << 0);
 273                                 }
 274                                 else if (Channel < 11)
 275                                 {
 276                                         DDRD  &= ~(1 << (Channel - 3));
 277                                         DIDR2 |=  (1 << (Channel - 8));
 278                                 }
 279                                 else
 280                                 {
 281                                         DDRB  &= ~(1 << (Channel - 7));
 282                                         DIDR2 |=  (1 << (Channel - 8));
 283                                 }
 284                                 #endif
 285                         }
 286
 287                         /** Starts the reading of the given channel, but does not wait until the conversion has completed.
 288                          *  Once executed, the conversion status can be determined via the \ref ADC_IsReadingComplete() macro and
 289                          *  the result read via the \ref ADC_GetResult() macro.
 290                          *
 291                          *  \param[in] MUXMask  Mask comprising of an ADC channel mask, reference mask and adjustment mask
 292                          */
 293                         static inline void ADC_StartReading(const uint8_t MUXMask)
 294                         {
 295                                 ADMUX = MUXMask;
 296
 297                                 ADCSRA |= (1 << ADSC);
 298                         }
 299
 300                         /** Performs a complete single reading from channel, including a polling spin-loop to wait for the
 301                          *  conversion to complete, and the returning of the converted value.
 302                          *
 303                          *  \param[in] MUXMask  Mask comprising of an ADC channel mask, reference mask and adjustment mask
 304                          */
 305                         static inline uint16_t ADC_GetChannelReading(const uint8_t MUXMask) ATTR_WARN_UNUSED_RESULT;
 306                         static inline uint16_t ADC_GetChannelReading(const uint8_t MUXMask)
 307                         {
 308                                 ADC_StartReading(MUXMask);
 309
 310                                 while (!(ADC_IsReadingComplete()));
 311
 312                                 return ADC_GetResult();
 313                         }
 314
 315         /* Disable C linkage for C++ Compilers: */
 316                 #if defined(__cplusplus)
 317                         }
 318                 #endif
 319
 320 #endif
 321
 322 /** @} */