LUFA/Drivers/Peripheral/AVR8/ADC_AVR8.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2011.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2011  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  *  \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                           defined(__AVR_ATmega32U6__))
  98                         #error The ADC peripheral driver is not currently available for your selected microcontroller model.
  99                 #endif
 100
 101         /* Private Interface - For use in library only: */
 102         #if !defined(__DOXYGEN__)
 103                 /* Macros: */
 104                         #define _ADC_GET_MUX_MASK2(y)           ADC_CHANNEL ## y
 105                         #define _ADC_GET_MUX_MASK(y)            _ADC_GET_MUX_MASK2(y)
 106         #endif
 107
 108         /* Public Interface - May be used in end-application: */
 109                 /* Macros: */
 110                         /** \name ADC Reference Configuration Masks */
 111                         //@{
 112                         /** Reference mask, for using the voltage present at the AVR's AREF pin for the ADC reference. */
 113                         #define ADC_REFERENCE_AREF              0
 114
 115                         /** Reference mask, for using the voltage present at the AVR's AVCC pin for the ADC reference. */
 116                         #define ADC_REFERENCE_AVCC              (1 << REFS0)
 117
 118                         /** Reference mask, for using the internally generated 2.56V reference voltage as the ADC reference. */
 119                         #define ADC_REFERENCE_INT2560MV         ((1 << REFS1) | (1 << REFS0))
 120                         //@}
 121
 122                         /** \name ADC Result Adjustment Configuration Masks */
 123                         //@{
 124                         /** Left-adjusts the 10-bit ADC result, so that the upper 8 bits of the value returned by the
 125                          *  \ref ADC_GetResult() macro contain the 8 most significant bits of the result.
 126                          */
 127                         #define ADC_LEFT_ADJUSTED               (1 << ADLAR)
 128
 129                         /** Right-adjusts the 10-bit ADC result, so that the lower 8 bits of the value returned by the
 130                          *  \ref ADC_GetResult() macro contain the 8 least significant bits of the result.
 131                          */
 132                         #define ADC_RIGHT_ADJUSTED              (0 << ADLAR)
 133                         //@}
 134
 135                         /** \name ADC Mode Configuration Masks */
 136                         //@{
 137                         /** Sets the ADC mode to free running, so that conversions take place continuously as fast as the ADC
 138                          *  is capable of at the given input clock speed.
 139                          */
 140                         #define ADC_FREE_RUNNING                (1 << ADATE)
 141
 142                         /** Sets the ADC mode to single conversion, so that only a single conversion will take place before
 143                          *  the ADC returns to idle.
 144                          */
 145                         #define ADC_SINGLE_CONVERSION           (0 << ADATE)
 146                         //@}
 147
 148                         /** \name ADC Prescaler Configuration Masks */
 149                         //@{
 150                         /** Sets the ADC input clock to prescale by a factor of 2 the AVR's system clock. */
 151                         #define ADC_PRESCALE_2                  (1 << ADPS0)
 152
 153                         /** Sets the ADC input clock to prescale by a factor of 4 the AVR's system clock. */
 154                         #define ADC_PRESCALE_4                  (1 << ADPS1)
 155
 156                         /** Sets the ADC input clock to prescale by a factor of 8 the AVR's system clock. */
 157                         #define ADC_PRESCALE_8                  ((1 << ADPS0) | (1 << ADPS1))
 158
 159                         /** Sets the ADC input clock to prescale by a factor of 16 the AVR's system clock. */
 160                         #define ADC_PRESCALE_16                 (1 << ADPS2)
 161
 162                         /** Sets the ADC input clock to prescale by a factor of 32 the AVR's system clock. */
 163                         #define ADC_PRESCALE_32                 ((1 << ADPS2) | (1 << ADPS0))
 164
 165                         /** Sets the ADC input clock to prescale by a factor of 64 the AVR's system clock. */
 166                         #define ADC_PRESCALE_64                 ((1 << ADPS2) | (1 << ADPS1))
 167
 168                         /** Sets the ADC input clock to prescale by a factor of 128 the AVR's system clock. */
 169                         #define ADC_PRESCALE_128                ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
 170                         //@}
 171
 172                         /** \name ADC MUX Masks */
 173                         //@{
 174                         /** MUX mask define for the ADC0 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 175                         #define ADC_CHANNEL0                    (0x00 << MUX0)
 176
 177                         /** MUX mask define for the ADC1 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 178                         #define ADC_CHANNEL1                    (0x01 << MUX0)
 179
 180                         #if !(defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 181                                 /** MUX mask define for the ADC2 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 182                                  *
 183                                  *  \note Not available on all AVR models.
 184                                  */
 185                                 #define ADC_CHANNEL2                (0x02 << MUX0)
 186
 187                                 /** MUX mask define for the ADC3 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 188                                  *
 189                                  *  \note Not available on all AVR models.
 190                                  */
 191                                 #define ADC_CHANNEL3                (0x03 << MUX0)
 192                         #endif
 193
 194                         /** MUX mask define for the ADC4 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 195                         #define ADC_CHANNEL4                    (0x04 << MUX0)
 196
 197                         /** MUX mask define for the ADC5 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 198                         #define ADC_CHANNEL5                    (0x05 << MUX0)
 199
 200                         /** MUX mask define for the ADC6 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 201                         #define ADC_CHANNEL6                    (0x06 << MUX0)
 202
 203                         /** MUX mask define for the ADC7 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 204                         #define ADC_CHANNEL7                    (0x07 << MUX0)
 205
 206                         /** MUX mask define for the internal 1.1V bandgap channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 207                         #define ADC_1100MV_BANDGAP              (0x1E << MUX0)
 208
 209                         #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 210                                 /** MUX mask define for the ADC8 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 211                                  *
 212                                  *  \note Not available on all AVR models.
 213                                  */
 214                                 #define ADC_CHANNEL8                ((1 << 8) | (0x00 << MUX0))
 215
 216                                 /** MUX mask define for the ADC9 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 217                                  *
 218                                  *  \note Not available on all AVR models.
 219                                  */
 220                                 #define ADC_CHANNEL9                ((1 << 8) | (0x01 << MUX0))
 221
 222                                 /** MUX mask define for the ADC10 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 223                                  *
 224                                  *  \note Not available on all AVR models.
 225                                  */
 226                                 #define ADC_CHANNEL10               ((1 << 8) | (0x02 << MUX0))
 227
 228                                 /** MUX mask define for the ADC11 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 229                                  *
 230                                  *  \note Not available on all AVR models.
 231                                  */
 232                                 #define ADC_CHANNEL11               ((1 << 8) | (0x03 << MUX0))
 233
 234                                 /** MUX mask define for the ADC12 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 235                                  *
 236                                  *  \note Not available on all AVR models.
 237                                  */
 238                                 #define ADC_CHANNEL12               ((1 << 8) | (0x04 << MUX0))
 239
 240                                 /** MUX mask define for the ADC13 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 241                                  *
 242                                  *  \note Not available on all AVR models.
 243                                  */
 244                                 #define ADC_CHANNEL13               ((1 << 8) | (0x05 << MUX0))
 245
 246                                 /** MUX mask define for the internal temperature sensor channel of the ADC. See \ref ADC_StartReading() and
 247                                  *  \ref ADC_GetChannelReading().
 248                                  *
 249                                  *  \note Not available on all AVR models.
 250                                  */
 251                                 #define ADC_INT_TEMP_SENS           ((1 << 8) | (0x07 << MUX0))
 252                         #endif
 253
 254                         /** Retrieves the ADC MUX mask for the given ADC channel number.
 255                          *
 256                          *  \note This macro will only work correctly on channel numbers that are compile-time
 257                          *        constants defined by the preprocessor.
 258                          *
 259                          *  \param[in] Channel  Index of the ADC channel whose MUX mask is to be retrieved.
 260                          */
 261                         #define ADC_GET_CHANNEL_MASK(Channel)   _ADC_GET_MUX_MASK(Channel)
 262                         //@}
 263
 264                 /* Inline Functions: */
 265                         /** Configures the given ADC channel, ready for ADC conversions. This function sets the
 266                          *  associated port pin as an input and disables the digital portion of the I/O to reduce
 267                          *  power consumption.
 268                          *
 269                          *  \note This must only be called for ADC channels with are connected to a physical port
 270                          *        pin of the AVR, denoted by its special alternative function ADCx.
 271                          *        \n\n
 272                          *
 273                          *  \note The channel number must be specified as an integer, and <b>not</b> a \c ADC_CHANNEL* mask.
 274                          *
 275                          *  \param[in] ChannelIndex  ADC channel number to set up for conversions.
 276                          */
 277                         static inline void ADC_SetupChannel(const uint8_t ChannelIndex)
 278                         {
 279                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 280                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
 281                                          defined(__AVR_ATmega32U6__))
 282                                 DDRF  &= ~(1 << ChannelIndex);
 283                                 DIDR0 |=  (1 << ChannelIndex);
 284                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 285                                 if (ChannelIndex < 8)
 286                                 {
 287                                         DDRF  &= ~(1 << ChannelIndex);
 288                                         DIDR0 |=  (1 << ChannelIndex);
 289                                 }
 290                                 else if (ChannelIndex == 8)
 291                                 {
 292                                         DDRD  &= ~(1 << 4);
 293                                         DIDR2 |=  (1 << 0);
 294                                 }
 295                                 else if (ChannelIndex < 11)
 296                                 {
 297                                         DDRD  &= ~(1 << (ChannelIndex - 3));
 298                                         DIDR2 |=  (1 << (ChannelIndex - 8));
 299                                 }
 300                                 else
 301                                 {
 302                                         DDRB  &= ~(1 << (ChannelIndex - 7));
 303                                         DIDR2 |=  (1 << (ChannelIndex - 8));
 304                                 }
 305                                 #endif
 306                         }
 307
 308                         /** De-configures the given ADC channel, re-enabling digital I/O mode instead of analog. This
 309                          *  function sets the associated port pin as an input and re-enabled the digital portion of
 310                          *  the I/O.
 311                          *
 312                          *  \note This must only be called for ADC channels with are connected to a physical port
 313                          *        pin of the AVR, denoted by its special alternative function ADCx.
 314                          *        \n\n
 315                          *
 316                          *  \note The channel number must be specified as an integer, and <b>not</b> a \c ADC_CHANNEL* mask.
 317                          *
 318                          *  \param[in] ChannelIndex  ADC channel number to set up for conversions.
 319                          */
 320                         static inline void ADC_DisableChannel(const uint8_t ChannelIndex)
 321                         {
 322                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 323                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
 324                                          defined(__AVR_ATmega32U6__))
 325                                 DDRF  &= ~(1 << ChannelIndex);
 326                                 DIDR0 &= ~(1 << ChannelIndex);
 327                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 328                                 if (ChannelIndex < 8)
 329                                 {
 330                                         DDRF  &= ~(1 << ChannelIndex);
 331                                         DIDR0 &= ~(1 << ChannelIndex);
 332                                 }
 333                                 else if (ChannelIndex == 8)
 334                                 {
 335                                         DDRD  &= ~(1 << 4);
 336                                         DIDR2 &= ~(1 << 0);
 337                                 }
 338                                 else if (ChannelIndex < 11)
 339                                 {
 340                                         DDRD  &= ~(1 << (ChannelIndex - 3));
 341                                         DIDR2 &= ~(1 << (ChannelIndex - 8));
 342                                 }
 343                                 else
 344                                 {
 345                                         DDRB  &= ~(1 << (ChannelIndex - 7));
 346                                         DIDR2 &= ~(1 << (ChannelIndex - 8));
 347                                 }
 348                                 #endif
 349                         }
 350
 351                         /** Starts the reading of the given channel, but does not wait until the conversion has completed.
 352                          *  Once executed, the conversion status can be determined via the \ref ADC_IsReadingComplete() macro and
 353                          *  the result read via the \ref ADC_GetResult() macro.
 354                          *
 355                          *  If the ADC has been initialized in free running mode, calling this function once will begin the repeated
 356                          *  conversions. If the ADC is in single conversion mode (or the channel to convert from is to be changed),
 357                          *  this function must be called each time a conversion is to take place.
 358                          *
 359                          *  \param[in] MUXMask  ADC channel mask, reference mask and adjustment mask.
 360                          */
 361                         static inline void ADC_StartReading(const uint16_t MUXMask)
 362                         {
 363                                 ADMUX = MUXMask;
 364
 365                                 #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 366                                 if (MUXMask & (1 << 8))
 367                                   ADCSRB |=  (1 << MUX5);
 368                                 else
 369                                   ADCSRB &= ~(1 << MUX5);
 370                                 #endif
 371
 372                                 ADCSRA |= (1 << ADSC);
 373                         }
 374
 375                         /** Indicates if the current ADC conversion is completed, or still in progress.
 376                          *
 377                          *  \return Boolean false if the reading is still taking place, or true if the conversion is
 378                          *          complete and ready to be read out with \ref ADC_GetResult().
 379                          */
 380                         static inline bool ADC_IsReadingComplete(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 381                         static inline bool ADC_IsReadingComplete(void)
 382                         {
 383                                 return ((ADCSRA & (1 << ADIF)) ? true : false);
 384                         }
 385
 386                         /** Retrieves the conversion value of the last completed ADC conversion and clears the reading
 387                          *  completion flag.
 388                          *
 389                          *  \return The result of the last ADC conversion as an unsigned value.
 390                          */
 391                         static inline uint16_t ADC_GetResult(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 392                         static inline uint16_t ADC_GetResult(void)
 393                         {
 394                                 ADCSRA |= (1 << ADIF);
 395                                 return ADC;
 396                         }
 397
 398                         /** Performs a complete single reading from channel, including a polling spin-loop to wait for the
 399                          *  conversion to complete, and the returning of the converted value.
 400                          *
 401                          *  \note For free running mode, the automated conversions should be initialized with a single call
 402                          *        to \ref ADC_StartReading() to select the channel and begin the automated conversions, and
 403                          *        the results read directly from the \ref ADC_GetResult() instead to reduce overhead.
 404                          *
 405                          *  \param[in] MUXMask  Mask comprising of an ADC channel mask, reference mask and adjustment mask.
 406                          */
 407                         static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask) ATTR_WARN_UNUSED_RESULT;
 408                         static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask)
 409                         {
 410                                 ADC_StartReading(MUXMask);
 411
 412                                 while (!(ADC_IsReadingComplete()));
 413
 414                                 return ADC_GetResult();
 415                         }
 416
 417                         /** Initializes the ADC, ready for conversions. This must be called before any other ADC operations.
 418                          *  The "mode" parameter should be a mask comprised of a conversion mode (free running or single) and
 419                          *  prescaler masks.
 420                          *
 421                          *  \param[in] Mode  Mask of ADC prescale and mode settings.
 422                          */
 423                         static inline void ADC_Init(uint8_t Mode) ATTR_ALWAYS_INLINE;
 424                         static inline void ADC_Init(uint8_t Mode)
 425                         {
 426                                 ADCSRA = ((1 << ADEN) | Mode);
 427                         }
 428
 429                         /** Turns off the ADC. If this is called, any further ADC operations will require a call to
 430                          *  \ref ADC_Init() before the ADC can be used again.
 431                          */
 432                         static inline void ADC_Disable(void) ATTR_ALWAYS_INLINE;
 433                         static inline void ADC_Disable(void)
 434                         {
 435                                 ADCSRA = 0;
 436                         }
 437
 438                         /** Indicates if the ADC is currently enabled.
 439                          *
 440                          *  \return Boolean \c true if the ADC subsystem is currently enabled, \c false otherwise.
 441                          */
 442                         static inline bool ADC_GetStatus(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 443                         static inline bool ADC_GetStatus(void)
 444                         {
 445                                 return ((ADCSRA & (1 << ADEN)) ? true : false);
 446                         }
 447
 448         /* Disable C linkage for C++ Compilers: */
 449                 #if defined(__cplusplus)
 450                         }
 451                 #endif
 452
 453 #endif
 454
 455 /** @} */
 456