LUFA/Drivers/Peripheral/AVR8/ADC_AVR8.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2013.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2013  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 disclaims 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  *  \brief ADC Peripheral Driver (AVR8)
  33  *
  34  *  On-chip Analogue-to-Digital converter (ADC) driver for supported U4, U6 and U7 model AVRs that contain an ADC
  35  *  peripheral internally.
  36  *
  37  *  \note This file should not be included directly. It is automatically included as needed by the ADC driver
  38  *        dispatch header located in LUFA/Drivers/Peripheral/ADC.h.
  39  */
  40
  41 /** \ingroup Group_ADC
  42  *  \defgroup Group_ADC_AVR8 ADC Peripheral Driver (AVR8)
  43  *
  44  *  \section Sec_ModDescription Module Description
  45  *  On-chip Analogue-to-Digital converter (ADC) driver for supported U4, U6 and U7 model AVRs that contain an ADC
  46  *  peripheral internally.
  47  *
  48  *  \note This file should not be included directly. It is automatically included as needed by the ADC driver
  49  *        dispatch header located in LUFA/Drivers/Peripheral/ADC.h.
  50  *
  51  *  \section Sec_ExampleUsage Example Usage
  52  *  The following snippet is an example of how this module may be used within a typical
  53  *  application.
  54  *
  55  *  \code
  56  *      // Initialize the ADC driver before first use
  57  *      ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
  58  *
  59  *      // Must setup the ADC channel to read beforehand
  60  *      ADC_SetupChannel(1);
  61  *
  62  *      // Perform a single conversion of the ADC channel 1
  63  *      ADC_GetChannelReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | ADC_CHANNEL1);
  64  *      printf("Conversion Result: %d\r\n", ADC_GetResult());
  65  *
  66  *      // Start reading ADC channel 1 in free running (continuous conversion) mode
  67  *      ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | ADC_CHANNEL1);
  68  *      for (;;)
  69  *      {
  70  *           while (!(ADC_IsReadingComplete())) {};
  71  *           printf("Conversion Result: %d\r\n", ADC_GetResult());
  72  *      }
  73  *  \endcode
  74  *
  75  *  @{
  76  */
  77
  78 #ifndef __ADC_AVR8_H__
  79 #define __ADC_AVR8_H__
  80
  81         /* Includes: */
  82                 #include "../../../Common/Common.h"
  83
  84         /* Enable C linkage for C++ Compilers: */
  85                 #if defined(__cplusplus)
  86                         extern "C" {
  87                 #endif
  88
  89         /* Preprocessor Checks: */
  90                 #if !defined(__INCLUDE_FROM_ADC_H)
  91                         #error Do not include this file directly. Include LUFA/Drivers/Peripheral/ADC.h instead.
  92                 #endif
  93
  94                 #if !(defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
  95                       defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
  96                           defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__))
  97                         #error The ADC peripheral driver is not currently available for your selected microcontroller model.
  98                 #endif
  99
 100         /* Private Interface - For use in library only: */
 101         #if !defined(__DOXYGEN__)
 102                 /* Macros: */
 103                         #define _ADC_GET_MUX_MASK2(y)           ADC_CHANNEL ## y
 104                         #define _ADC_GET_MUX_MASK(y)            _ADC_GET_MUX_MASK2(y)
 105         #endif
 106
 107         /* Public Interface - May be used in end-application: */
 108                 /* Macros: */
 109                         /** \name ADC Reference Configuration Masks */
 110                         //@{
 111                         /** Reference mask, for using the voltage present at the AVR's AREF pin for the ADC reference. */
 112                         #define ADC_REFERENCE_AREF              0
 113
 114                         /** Reference mask, for using the voltage present at the AVR's AVCC pin for the ADC reference. */
 115                         #define ADC_REFERENCE_AVCC              (1 << REFS0)
 116
 117                         /** Reference mask, for using the internally generated 2.56V reference voltage as the ADC reference. */
 118                         #define ADC_REFERENCE_INT2560MV         ((1 << REFS1) | (1 << REFS0))
 119                         //@}
 120
 121                         /** \name ADC Result Adjustment Configuration Masks */
 122                         //@{
 123                         /** Left-adjusts the 10-bit ADC result, so that the upper 8 bits of the value returned by the
 124                          *  \ref ADC_GetResult() macro contain the 8 most significant bits of the result.
 125                          */
 126                         #define ADC_LEFT_ADJUSTED               (1 << ADLAR)
 127
 128                         /** Right-adjusts the 10-bit ADC result, so that the lower 8 bits of the value returned by the
 129                          *  \ref ADC_GetResult() macro contain the 8 least significant bits of the result.
 130                          */
 131                         #define ADC_RIGHT_ADJUSTED              (0 << ADLAR)
 132                         //@}
 133
 134                         /** \name ADC Mode Configuration Masks */
 135                         //@{
 136                         /** Sets the ADC mode to free running, so that conversions take place continuously as fast as the ADC
 137                          *  is capable of at the given input clock speed.
 138                          */
 139                         #define ADC_FREE_RUNNING                (1 << ADATE)
 140
 141                         /** Sets the ADC mode to single conversion, so that only a single conversion will take place before
 142                          *  the ADC returns to idle.
 143                          */
 144                         #define ADC_SINGLE_CONVERSION           (0 << ADATE)
 145                         //@}
 146
 147                         /** \name ADC Prescaler Configuration Masks */
 148                         //@{
 149                         /** Sets the ADC input clock to prescale by a factor of 2 the AVR's system clock. */
 150                         #define ADC_PRESCALE_2                  (1 << ADPS0)
 151
 152                         /** Sets the ADC input clock to prescale by a factor of 4 the AVR's system clock. */
 153                         #define ADC_PRESCALE_4                  (1 << ADPS1)
 154
 155                         /** Sets the ADC input clock to prescale by a factor of 8 the AVR's system clock. */
 156                         #define ADC_PRESCALE_8                  ((1 << ADPS0) | (1 << ADPS1))
 157
 158                         /** Sets the ADC input clock to prescale by a factor of 16 the AVR's system clock. */
 159                         #define ADC_PRESCALE_16                 (1 << ADPS2)
 160
 161                         /** Sets the ADC input clock to prescale by a factor of 32 the AVR's system clock. */
 162                         #define ADC_PRESCALE_32                 ((1 << ADPS2) | (1 << ADPS0))
 163
 164                         /** Sets the ADC input clock to prescale by a factor of 64 the AVR's system clock. */
 165                         #define ADC_PRESCALE_64                 ((1 << ADPS2) | (1 << ADPS1))
 166
 167                         /** Sets the ADC input clock to prescale by a factor of 128 the AVR's system clock. */
 168                         #define ADC_PRESCALE_128                ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
 169                         //@}
 170
 171                         /** \name ADC MUX Masks */
 172                         //@{
 173                         /** MUX mask define for the ADC0 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 174                         #define ADC_CHANNEL0                    (0x00 << MUX0)
 175
 176                         /** MUX mask define for the ADC1 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 177                         #define ADC_CHANNEL1                    (0x01 << MUX0)
 178
 179                         #if (!(defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)) || defined(__DOXYGEN__))
 180                                 /** MUX mask define for the ADC2 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 181                                  *
 182                                  *  \note Not available on all AVR models.
 183                                  */
 184                                 #define ADC_CHANNEL2                (0x02 << MUX0)
 185
 186                                 /** MUX mask define for the ADC3 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 187                                  *
 188                                  *  \note Not available on all AVR models.
 189                                  */
 190                                 #define ADC_CHANNEL3                (0x03 << MUX0)
 191                         #endif
 192
 193                         /** MUX mask define for the ADC4 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 194                         #define ADC_CHANNEL4                    (0x04 << MUX0)
 195
 196                         /** MUX mask define for the ADC5 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 197                         #define ADC_CHANNEL5                    (0x05 << MUX0)
 198
 199                         /** MUX mask define for the ADC6 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 200                         #define ADC_CHANNEL6                    (0x06 << MUX0)
 201
 202                         /** MUX mask define for the ADC7 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 203                         #define ADC_CHANNEL7                    (0x07 << MUX0)
 204
 205                         #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 206                                 /** MUX mask define for the ADC8 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 207                                  *
 208                                  *  \note Not available on all AVR models.
 209                                  */
 210                                 #define ADC_CHANNEL8                ((1 << 8) | (0x00 << MUX0))
 211
 212                                 /** MUX mask define for the ADC9 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 213                                  *
 214                                  *  \note Not available on all AVR models.
 215                                  */
 216                                 #define ADC_CHANNEL9                ((1 << 8) | (0x01 << MUX0))
 217
 218                                 /** MUX mask define for the ADC10 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 219                                  *
 220                                  *  \note Not available on all AVR models.
 221                                  */
 222                                 #define ADC_CHANNEL10               ((1 << 8) | (0x02 << MUX0))
 223
 224                                 /** MUX mask define for the ADC11 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 225                                  *
 226                                  *  \note Not available on all AVR models.
 227                                  */
 228                                 #define ADC_CHANNEL11               ((1 << 8) | (0x03 << MUX0))
 229
 230                                 /** MUX mask define for the ADC12 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 231                                  *
 232                                  *  \note Not available on all AVR models.
 233                                  */
 234                                 #define ADC_CHANNEL12               ((1 << 8) | (0x04 << MUX0))
 235
 236                                 /** MUX mask define for the ADC13 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 237                                  *
 238                                  *  \note Not available on all AVR models.
 239                                  */
 240                                 #define ADC_CHANNEL13               ((1 << 8) | (0x05 << MUX0))
 241
 242                                 /** MUX mask define for the internal temperature sensor channel of the ADC. See \ref ADC_StartReading() and
 243                                  *  \ref ADC_GetChannelReading().
 244                                  *
 245                                  *  \note Not available on all AVR models.
 246                                  */
 247                                 #define ADC_INT_TEMP_SENS           ((1 << 8) | (0x07 << MUX0))
 248                         #endif
 249
 250                         /** MUX mask define for the internal 1.1V band-gap channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 251                         #define ADC_1100MV_BANDGAP              (0x1E << MUX0)
 252
 253                         /** Retrieves the ADC MUX mask for the given ADC channel number.
 254                          *
 255                          *  \attention This macro will only work correctly on channel numbers that are compile-time
 256                          *             constants defined by the preprocessor.
 257                          *
 258                          *  \param[in] Channel  Index of the ADC channel whose MUX mask is to be retrieved.
 259                          */
 260                         #define ADC_GET_CHANNEL_MASK(Channel)   _ADC_GET_MUX_MASK(Channel)
 261                         //@}
 262
 263                 /* Inline Functions: */
 264                         /** Configures the given ADC channel, ready for ADC conversions. This function sets the
 265                          *  associated port pin as an input and disables the digital portion of the I/O to reduce
 266                          *  power consumption.
 267                          *
 268                          *  \note This must only be called for ADC channels with are connected to a physical port
 269                          *        pin of the AVR, denoted by its special alternative function ADCx.
 270                          *
 271                          *  \warning The channel number must be specified as an integer, and <b>not</b> a \c ADC_CHANNEL* mask.
 272                          *
 273                          *  \param[in] ChannelIndex  ADC channel number to set up for conversions.
 274                          */
 275                         static inline void ADC_SetupChannel(const uint8_t ChannelIndex)
 276                         {
 277                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 278                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__))
 279                                 DDRF  &= ~(1 << ChannelIndex);
 280                                 DIDR0 |=  (1 << ChannelIndex);
 281                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 282                                 if (ChannelIndex < 8)
 283                                 {
 284                                         DDRF  &= ~(1 << ChannelIndex);
 285                                         DIDR0 |=  (1 << ChannelIndex);
 286                                 }
 287                                 else if (ChannelIndex == 8)
 288                                 {
 289                                         DDRD  &= ~(1 << 4);
 290                                         DIDR2 |=  (1 << 0);
 291                                 }
 292                                 else if (ChannelIndex < 11)
 293                                 {
 294                                         DDRD  &= ~(1 << (ChannelIndex - 3));
 295                                         DIDR2 |=  (1 << (ChannelIndex - 8));
 296                                 }
 297                                 else
 298                                 {
 299                                         DDRB  &= ~(1 << (ChannelIndex - 7));
 300                                         DIDR2 |=  (1 << (ChannelIndex - 8));
 301                                 }
 302                                 #endif
 303                         }
 304
 305                         /** De-configures the given ADC channel, re-enabling digital I/O mode instead of analog. This
 306                          *  function sets the associated port pin as an input and re-enabled the digital portion of
 307                          *  the I/O.
 308                          *
 309                          *  \note This must only be called for ADC channels with are connected to a physical port
 310                          *        pin of the AVR, denoted by its special alternative function ADCx.
 311                          *
 312                          *  \warning The channel number must be specified as an integer, and <b>not</b> a \c ADC_CHANNEL* mask.
 313                          *
 314                          *  \param[in] ChannelIndex  ADC channel number to set up for conversions.
 315                          */
 316                         static inline void ADC_DisableChannel(const uint8_t ChannelIndex)
 317                         {
 318                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 319                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__))
 320                                 DDRF  &= ~(1 << ChannelIndex);
 321                                 DIDR0 &= ~(1 << ChannelIndex);
 322                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 323                                 if (ChannelIndex < 8)
 324                                 {
 325                                         DDRF  &= ~(1 << ChannelIndex);
 326                                         DIDR0 &= ~(1 << ChannelIndex);
 327                                 }
 328                                 else if (ChannelIndex == 8)
 329                                 {
 330                                         DDRD  &= ~(1 << 4);
 331                                         DIDR2 &= ~(1 << 0);
 332                                 }
 333                                 else if (ChannelIndex < 11)
 334                                 {
 335                                         DDRD  &= ~(1 << (ChannelIndex - 3));
 336                                         DIDR2 &= ~(1 << (ChannelIndex - 8));
 337                                 }
 338                                 else
 339                                 {
 340                                         DDRB  &= ~(1 << (ChannelIndex - 7));
 341                                         DIDR2 &= ~(1 << (ChannelIndex - 8));
 342                                 }
 343                                 #endif
 344                         }
 345
 346                         /** Starts the reading of the given channel, but does not wait until the conversion has completed.
 347                          *  Once executed, the conversion status can be determined via the \ref ADC_IsReadingComplete() macro and
 348                          *  the result read via the \ref ADC_GetResult() macro.
 349                          *
 350                          *  If the ADC has been initialized in free running mode, calling this function once will begin the repeated
 351                          *  conversions. If the ADC is in single conversion mode (or the channel to convert from is to be changed),
 352                          *  this function must be called each time a conversion is to take place.
 353                          *
 354                          *  \param[in] MUXMask  ADC channel mask, reference mask and adjustment mask.
 355                          */
 356                         static inline void ADC_StartReading(const uint16_t MUXMask)
 357                         {
 358                                 ADMUX = MUXMask;
 359
 360                                 #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 361                                 if (MUXMask & (1 << 8))
 362                                   ADCSRB |=  (1 << MUX5);
 363                                 else
 364                                   ADCSRB &= ~(1 << MUX5);
 365                                 #endif
 366
 367                                 ADCSRA |= (1 << ADSC);
 368                         }
 369
 370                         /** Indicates if the current ADC conversion is completed, or still in progress.
 371                          *
 372                          *  \return Boolean \c false if the reading is still taking place, or true if the conversion is
 373                          *          complete and ready to be read out with \ref ADC_GetResult().
 374                          */
 375                         static inline bool ADC_IsReadingComplete(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 376                         static inline bool ADC_IsReadingComplete(void)
 377                         {
 378                                 return ((ADCSRA & (1 << ADIF)) ? true : false);
 379                         }
 380
 381                         /** Retrieves the conversion value of the last completed ADC conversion and clears the reading
 382                          *  completion flag.
 383                          *
 384                          *  \return The result of the last ADC conversion as an unsigned value.
 385                          */
 386                         static inline uint16_t ADC_GetResult(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 387                         static inline uint16_t ADC_GetResult(void)
 388                         {
 389                                 ADCSRA |= (1 << ADIF);
 390                                 return ADC;
 391                         }
 392
 393                         /** Performs a complete single reading from channel, including a polling spin-loop to wait for the
 394                          *  conversion to complete, and the returning of the converted value.
 395                          *
 396                          *  \note For free running mode, the automated conversions should be initialized with a single call
 397                          *        to \ref ADC_StartReading() to select the channel and begin the automated conversions, and
 398                          *        the results read directly from the \ref ADC_GetResult() instead to reduce overhead.
 399                          *
 400                          *  \param[in] MUXMask  Mask comprising of an ADC channel mask, reference mask and adjustment mask.
 401                          *
 402                          *  \return Converted ADC result for the given ADC channel.
 403                          */
 404                         static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask) ATTR_WARN_UNUSED_RESULT;
 405                         static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask)
 406                         {
 407                                 ADC_StartReading(MUXMask);
 408
 409                                 while (!(ADC_IsReadingComplete()));
 410
 411                                 return ADC_GetResult();
 412                         }
 413
 414                         /** Initializes the ADC, ready for conversions. This must be called before any other ADC operations.
 415                          *  The "mode" parameter should be a mask comprised of a conversion mode (free running or single) and
 416                          *  prescaler masks.
 417                          *
 418                          *  \param[in] Mode  Mask of ADC prescale and mode settings.
 419                          */
 420                         static inline void ADC_Init(const uint8_t Mode) ATTR_ALWAYS_INLINE;
 421                         static inline void ADC_Init(const uint8_t Mode)
 422                         {
 423                                 ADCSRA = ((1 << ADEN) | Mode);
 424                         }
 425
 426                         /** Turns off the ADC. If this is called, any further ADC operations will require a call to
 427                          *  \ref ADC_Init() before the ADC can be used again.
 428                          */
 429                         static inline void ADC_Disable(void) ATTR_ALWAYS_INLINE;
 430                         static inline void ADC_Disable(void)
 431                         {
 432                                 ADCSRA = 0;
 433                         }
 434
 435                         /** Indicates if the ADC is currently enabled.
 436                          *
 437                          *  \return Boolean \c true if the ADC subsystem is currently enabled, \c false otherwise.
 438                          */
 439                         static inline bool ADC_GetStatus(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 440                         static inline bool ADC_GetStatus(void)
 441                         {
 442                                 return ((ADCSRA & (1 << ADEN)) ? true : false);
 443                         }
 444
 445         /* Disable C linkage for C++ Compilers: */
 446                 #if defined(__cplusplus)
 447                         }
 448                 #endif
 449
 450 #endif
 451
 452 /** @} */
 453