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_ADC_AVR8_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_ADC_AVR8_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         /* Public Interface - May be used in end-application: */
 101                 /* Macros: */
 102                         /** \name ADC Reference Configuration Masks */
 103                         //@{
 104                         /** Reference mask, for using the voltage present at the AVR's AREF pin for the ADC reference. */
 105                         #define ADC_REFERENCE_AREF              0
 106
 107                         /** Reference mask, for using the voltage present at the AVR's AVCC pin for the ADC reference. */
 108                         #define ADC_REFERENCE_AVCC              (1 << REFS0)
 109
 110                         /** Reference mask, for using the internally generated 2.56V reference voltage as the ADC reference. */
 111                         #define ADC_REFERENCE_INT2560MV         ((1 << REFS1) | (1 << REFS0))
 112                         //@}
 113
 114                         /** \name ADC Result Adjustment Configuration Masks */
 115                         //@{
 116                         /** Left-adjusts the 10-bit ADC result, so that the upper 8 bits of the value returned by the
 117                          *  \ref ADC_GetResult() macro contain the 8 most significant bits of the result.
 118                          */
 119                         #define ADC_LEFT_ADJUSTED               (1 << ADLAR)
 120
 121                         /** Right-adjusts the 10-bit ADC result, so that the lower 8 bits of the value returned by the
 122                          *  \ref ADC_GetResult() macro contain the 8 least significant bits of the result.
 123                          */
 124                         #define ADC_RIGHT_ADJUSTED              (0 << ADLAR)
 125                         //@}
 126
 127                         /** \name ADC Mode Configuration Masks */
 128                         //@{
 129                         /** Sets the ADC mode to free running, so that conversions take place continuously as fast as the ADC
 130                          *  is capable of at the given input clock speed.
 131                          */
 132                         #define ADC_FREE_RUNNING                (1 << ADATE)
 133
 134                         /** Sets the ADC mode to single conversion, so that only a single conversion will take place before
 135                          *  the ADC returns to idle.
 136                          */
 137                         #define ADC_SINGLE_CONVERSION           (0 << ADATE)
 138                         //@}
 139
 140                         /** \name ADC Prescaler Configuration Masks */
 141                         //@{
 142                         /** Sets the ADC input clock to prescale by a factor of 2 the AVR's system clock. */
 143                         #define ADC_PRESCALE_2                  (1 << ADPS0)
 144
 145                         /** Sets the ADC input clock to prescale by a factor of 4 the AVR's system clock. */
 146                         #define ADC_PRESCALE_4                  (1 << ADPS1)
 147
 148                         /** Sets the ADC input clock to prescale by a factor of 8 the AVR's system clock. */
 149                         #define ADC_PRESCALE_8                  ((1 << ADPS0) | (1 << ADPS1))
 150
 151                         /** Sets the ADC input clock to prescale by a factor of 16 the AVR's system clock. */
 152                         #define ADC_PRESCALE_16                 (1 << ADPS2)
 153
 154                         /** Sets the ADC input clock to prescale by a factor of 32 the AVR's system clock. */
 155                         #define ADC_PRESCALE_32                 ((1 << ADPS2) | (1 << ADPS0))
 156
 157                         /** Sets the ADC input clock to prescale by a factor of 64 the AVR's system clock. */
 158                         #define ADC_PRESCALE_64                 ((1 << ADPS2) | (1 << ADPS1))
 159
 160                         /** Sets the ADC input clock to prescale by a factor of 128 the AVR's system clock. */
 161                         #define ADC_PRESCALE_128                ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
 162                         //@}
 163
 164                         /** \name ADC MUX Masks */
 165                         //@{
 166                         /** MUX mask define for the ADC0 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 167                         #define ADC_CHANNEL0                    (0x00 << MUX0)
 168
 169                         /** MUX mask define for the ADC1 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 170                         #define ADC_CHANNEL1                    (0x01 << MUX0)
 171
 172                         #if (!(defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)) || defined(__DOXYGEN__))
 173                                 /** MUX mask define for the ADC2 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 174                                  *
 175                                  *  \note Not available on all AVR models.
 176                                  */
 177                                 #define ADC_CHANNEL2                (0x02 << MUX0)
 178
 179                                 /** MUX mask define for the ADC3 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 180                                  *
 181                                  *  \note Not available on all AVR models.
 182                                  */
 183                                 #define ADC_CHANNEL3                (0x03 << MUX0)
 184                         #endif
 185
 186                         /** MUX mask define for the ADC4 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 187                         #define ADC_CHANNEL4                    (0x04 << MUX0)
 188
 189                         /** MUX mask define for the ADC5 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 190                         #define ADC_CHANNEL5                    (0x05 << MUX0)
 191
 192                         /** MUX mask define for the ADC6 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 193                         #define ADC_CHANNEL6                    (0x06 << MUX0)
 194
 195                         /** MUX mask define for the ADC7 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 196                         #define ADC_CHANNEL7                    (0x07 << MUX0)
 197
 198                         #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 199                                 /** MUX mask define for the ADC8 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 200                                  *
 201                                  *  \note Not available on all AVR models.
 202                                  */
 203                                 #define ADC_CHANNEL8                ((1 << 8) | (0x00 << MUX0))
 204
 205                                 /** MUX mask define for the ADC9 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 206                                  *
 207                                  *  \note Not available on all AVR models.
 208                                  */
 209                                 #define ADC_CHANNEL9                ((1 << 8) | (0x01 << MUX0))
 210
 211                                 /** MUX mask define for the ADC10 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 212                                  *
 213                                  *  \note Not available on all AVR models.
 214                                  */
 215                                 #define ADC_CHANNEL10               ((1 << 8) | (0x02 << MUX0))
 216
 217                                 /** MUX mask define for the ADC11 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 218                                  *
 219                                  *  \note Not available on all AVR models.
 220                                  */
 221                                 #define ADC_CHANNEL11               ((1 << 8) | (0x03 << MUX0))
 222
 223                                 /** MUX mask define for the ADC12 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 224                                  *
 225                                  *  \note Not available on all AVR models.
 226                                  */
 227                                 #define ADC_CHANNEL12               ((1 << 8) | (0x04 << MUX0))
 228
 229                                 /** MUX mask define for the ADC13 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
 230                                  *
 231                                  *  \note Not available on all AVR models.
 232                                  */
 233                                 #define ADC_CHANNEL13               ((1 << 8) | (0x05 << MUX0))
 234
 235                                 /** MUX mask define for the internal temperature sensor channel of the ADC. See \ref ADC_StartReading() and
 236                                  *  \ref ADC_GetChannelReading().
 237                                  *
 238                                  *  \note Not available on all AVR models.
 239                                  */
 240                                 #define ADC_INT_TEMP_SENS           ((1 << 8) | (0x07 << MUX0))
 241                         #endif
 242
 243                         /** MUX mask define for the internal 1.1V band-gap channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
 244                         #define ADC_1100MV_BANDGAP              (0x1E << MUX0)
 245
 246                         /** Retrieves the ADC MUX mask for the given ADC channel number.
 247                          *
 248                          *  \attention This macro will only work correctly on channel numbers that are compile-time
 249                          *             constants defined by the preprocessor.
 250                          *
 251                          *  \param[in] Channel  Index of the ADC channel whose MUX mask is to be retrieved.
 252                          */
 253                         #define ADC_GET_CHANNEL_MASK(Channel)   CONCAT_EXPANDED(ADC_CHANNEL, Channel)
 254                         //@}
 255
 256                 /* Inline Functions: */
 257                         /** Configures the given ADC channel, ready for ADC conversions. This function sets the
 258                          *  associated port pin as an input and disables the digital portion of the I/O to reduce
 259                          *  power consumption.
 260                          *
 261                          *  \note This must only be called for ADC channels with are connected to a physical port
 262                          *        pin of the AVR, denoted by its special alternative function ADCx.
 263                          *
 264                          *  \warning The channel number must be specified as an integer, and <b>not</b> a \c ADC_CHANNEL* mask.
 265                          *
 266                          *  \param[in] ChannelIndex  ADC channel number to set up for conversions.
 267                          */
 268                         static inline void ADC_SetupChannel(const uint8_t ChannelIndex)
 269                         {
 270                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 271                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__))
 272                                 DDRF  &= ~(1 << ChannelIndex);
 273                                 DIDR0 |=  (1 << ChannelIndex);
 274                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 275                                 if (ChannelIndex < 8)
 276                                 {
 277                                         DDRF  &= ~(1 << ChannelIndex);
 278                                         DIDR0 |=  (1 << ChannelIndex);
 279                                 }
 280                                 else if (ChannelIndex == 8)
 281                                 {
 282                                         DDRD  &= ~(1 << 4);
 283                                         DIDR2 |=  (1 << 0);
 284                                 }
 285                                 else if (ChannelIndex < 11)
 286                                 {
 287                                         DDRD  &= ~(1 << (ChannelIndex - 3));
 288                                         DIDR2 |=  (1 << (ChannelIndex - 8));
 289                                 }
 290                                 else
 291                                 {
 292                                         DDRB  &= ~(1 << (ChannelIndex - 7));
 293                                         DIDR2 |=  (1 << (ChannelIndex - 8));
 294                                 }
 295                                 #endif
 296                         }
 297
 298                         /** De-configures the given ADC channel, re-enabling digital I/O mode instead of analog. This
 299                          *  function sets the associated port pin as an input and re-enabled the digital portion of
 300                          *  the I/O.
 301                          *
 302                          *  \note This must only be called for ADC channels with are connected to a physical port
 303                          *        pin of the AVR, denoted by its special alternative function ADCx.
 304                          *
 305                          *  \warning The channel number must be specified as an integer, and <b>not</b> a \c ADC_CHANNEL* mask.
 306                          *
 307                          *  \param[in] ChannelIndex  ADC channel number to set up for conversions.
 308                          */
 309                         static inline void ADC_DisableChannel(const uint8_t ChannelIndex)
 310                         {
 311                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 312                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__))
 313                                 DDRF  &= ~(1 << ChannelIndex);
 314                                 DIDR0 &= ~(1 << ChannelIndex);
 315                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 316                                 if (ChannelIndex < 8)
 317                                 {
 318                                         DDRF  &= ~(1 << ChannelIndex);
 319                                         DIDR0 &= ~(1 << ChannelIndex);
 320                                 }
 321                                 else if (ChannelIndex == 8)
 322                                 {
 323                                         DDRD  &= ~(1 << 4);
 324                                         DIDR2 &= ~(1 << 0);
 325                                 }
 326                                 else if (ChannelIndex < 11)
 327                                 {
 328                                         DDRD  &= ~(1 << (ChannelIndex - 3));
 329                                         DIDR2 &= ~(1 << (ChannelIndex - 8));
 330                                 }
 331                                 else
 332                                 {
 333                                         DDRB  &= ~(1 << (ChannelIndex - 7));
 334                                         DIDR2 &= ~(1 << (ChannelIndex - 8));
 335                                 }
 336                                 #endif
 337                         }
 338
 339                         /** Starts the reading of the given channel, but does not wait until the conversion has completed.
 340                          *  Once executed, the conversion status can be determined via the \ref ADC_IsReadingComplete() macro and
 341                          *  the result read via the \ref ADC_GetResult() macro.
 342                          *
 343                          *  If the ADC has been initialized in free running mode, calling this function once will begin the repeated
 344                          *  conversions. If the ADC is in single conversion mode (or the channel to convert from is to be changed),
 345                          *  this function must be called each time a conversion is to take place.
 346                          *
 347                          *  \param[in] MUXMask  ADC channel mask, reference mask and adjustment mask.
 348                          */
 349                         static inline void ADC_StartReading(const uint16_t MUXMask)
 350                         {
 351                                 ADMUX = MUXMask;
 352
 353                                 #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 354                                 if (MUXMask & (1 << 8))
 355                                   ADCSRB |=  (1 << MUX5);
 356                                 else
 357                                   ADCSRB &= ~(1 << MUX5);
 358                                 #endif
 359
 360                                 ADCSRA |= (1 << ADSC);
 361                         }
 362
 363                         /** Indicates if the current ADC conversion is completed, or still in progress.
 364                          *
 365                          *  \return Boolean \c false if the reading is still taking place, or true if the conversion is
 366                          *          complete and ready to be read out with \ref ADC_GetResult().
 367                          */
 368                         static inline bool ADC_IsReadingComplete(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 369                         static inline bool ADC_IsReadingComplete(void)
 370                         {
 371                                 return ((ADCSRA & (1 << ADIF)) ? true : false);
 372                         }
 373
 374                         /** Retrieves the conversion value of the last completed ADC conversion and clears the reading
 375                          *  completion flag.
 376                          *
 377                          *  \return The result of the last ADC conversion as an unsigned value.
 378                          */
 379                         static inline uint16_t ADC_GetResult(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 380                         static inline uint16_t ADC_GetResult(void)
 381                         {
 382                                 ADCSRA |= (1 << ADIF);
 383                                 return ADC;
 384                         }
 385
 386                         /** Performs a complete single reading from channel, including a polling spin-loop to wait for the
 387                          *  conversion to complete, and the returning of the converted value.
 388                          *
 389                          *  \note For free running mode, the automated conversions should be initialized with a single call
 390                          *        to \ref ADC_StartReading() to select the channel and begin the automated conversions, and
 391                          *        the results read directly from the \ref ADC_GetResult() instead to reduce overhead.
 392                          *
 393                          *  \param[in] MUXMask  Mask comprising of an ADC channel mask, reference mask and adjustment mask.
 394                          *
 395                          *  \return Converted ADC result for the given ADC channel.
 396                          */
 397                         static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask) ATTR_WARN_UNUSED_RESULT;
 398                         static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask)
 399                         {
 400                                 ADC_StartReading(MUXMask);
 401
 402                                 while (!(ADC_IsReadingComplete()));
 403
 404                                 return ADC_GetResult();
 405                         }
 406
 407                         /** Initializes the ADC, ready for conversions. This must be called before any other ADC operations.
 408                          *  The "mode" parameter should be a mask comprised of a conversion mode (free running or single) and
 409                          *  prescaler masks.
 410                          *
 411                          *  \param[in] Mode  Mask of ADC prescale and mode settings.
 412                          */
 413                         static inline void ADC_Init(const uint8_t Mode) ATTR_ALWAYS_INLINE;
 414                         static inline void ADC_Init(const uint8_t Mode)
 415                         {
 416                                 ADCSRA = ((1 << ADEN) | Mode);
 417                         }
 418
 419                         /** Turns off the ADC. If this is called, any further ADC operations will require a call to
 420                          *  \ref ADC_Init() before the ADC can be used again.
 421                          */
 422                         static inline void ADC_Disable(void) ATTR_ALWAYS_INLINE;
 423                         static inline void ADC_Disable(void)
 424                         {
 425                                 ADCSRA = 0;
 426                         }
 427
 428                         /** Indicates if the ADC is currently enabled.
 429                          *
 430                          *  \return Boolean \c true if the ADC subsystem is currently enabled, \c false otherwise.
 431                          */
 432                         static inline bool ADC_GetStatus(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 433                         static inline bool ADC_GetStatus(void)
 434                         {
 435                                 return ((ADCSRA & (1 << ADEN)) ? true : false);
 436                         }
 437
 438         /* Disable C linkage for C++ Compilers: */
 439                 #if defined(__cplusplus)
 440                         }
 441                 #endif
 442
 443 #endif
 444
 445 /** @} */
 446