LUFA/Drivers/Peripheral/AVRU4U6U7/ADC.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   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  *  \brief ADC peripheral driver for the U7, U6 and U4 USB AVRs.
  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_AVRU4U6U7 Series U4, U6 and U7 Model ADC Driver
  43  *
  44  *  On-chip Analogue-to-Digital converter (ADC) driver for supported U4, U6 and U7 model AVRs that contain an ADC
  45  *  peripheral internally.
  46  *
  47  *  \note This file should not be included directly. It is automatically included as needed by the ADC driver
  48  *        dispatch header located in LUFA/Drivers/Peripheral/ADC.h.
  49  *
  50  *  \section Sec_ExampleUsage Example Usage
  51  *  The following snippet is an example of how this module may be used within a typical
  52  *  application.
  53  *
  54  *  \code
  55  *      // Initialise the ADC driver before first use
  56  *      ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
  57  *
  58  *      // Must setup the ADC channel to read beforehand
  59  *      ADC_SetupChannel(1);
  60  *
  61  *      // Perform a single conversion of the ADC channel 1
  62  *      ADC_GetChannelReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | ADC_CHANNEL1);
  63  *      printf("Conversion Result: %d\r\n", ADC_GetResult());
  64  *
  65  *      // Start reading ADC channel 1 in free running (continuous conversion) mode
  66  *      ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | ADC_CHANNEL1);
  67  *      while (!(ADC_IsReadingComplete())) {};
  68  *      printf("Conversion Result: %d\r\n", ADC_GetResult());
  69  *  \endcode
  70  *
  71  *  @{
  72  */
  73
  74 #ifndef __ADC_AVRU4U6U7_H__
  75 #define __ADC_AVRU4U6U7_H__
  76
  77         /* Includes: */
  78                 #include "../../../Common/Common.h"
  79
  80                 #include <avr/io.h>
  81                 #include <stdbool.h>
  82
  83         /* Enable C linkage for C++ Compilers: */
  84                 #if defined(__cplusplus)
  85                         extern "C" {
  86                 #endif
  87
  88         /* Preprocessor Checks: */
  89                 #if !defined(__INCLUDE_FROM_ADC_H)
  90                         #error Do not include this file directly. Include LUFA/Drivers/Peripheral/ADC.h instead.
  91                 #endif
  92
  93         /* Public Interface - May be used in end-application: */
  94                 /* Macros: */
  95                         /** \name ADC Reference Configuration Masks */
  96                         //@{
  97                         /** Reference mask, for using the voltage present at the AVR's AREF pin for the ADC reference. */
  98                         #define ADC_REFERENCE_AREF              0
  99
 100                         /** Reference mask, for using the voltage present at the AVR's AVCC pin for the ADC reference. */
 101                         #define ADC_REFERENCE_AVCC              (1 << REFS0)
 102
 103                         /** Reference mask, for using the internally generated 2.56V reference voltage as the ADC reference. */
 104                         #define ADC_REFERENCE_INT2560MV         ((1 << REFS1) | (1 << REFS0))
 105                         //@}
 106
 107                         /** \name ADC Result Adjustment Configuration Masks */
 108                         //@{
 109                         /** Left-adjusts the 10-bit ADC result, so that the upper 8 bits of the value returned by the
 110                          *  ADC_GetResult() macro contain the 8 most significant bits of the result.
 111                          */
 112                         #define ADC_LEFT_ADJUSTED               (1 << ADLAR)
 113
 114                         /** Right-adjusts the 10-bit ADC result, so that the lower 8 bits of the value returned by the
 115                          *  ADC_GetResult() macro contain the 8 least significant bits of the result.
 116                          */
 117                         #define ADC_RIGHT_ADJUSTED              (0 << ADLAR)
 118                         //@}
 119
 120                         /** \name ADC Mode Configuration Masks */
 121                         //@{
 122                         /** Sets the ADC mode to free running, so that conversions take place continuously as fast as the ADC
 123                          *  is capable of at the given input clock speed.
 124                          */
 125                         #define ADC_FREE_RUNNING                (1 << ADATE)
 126
 127                         /** Sets the ADC mode to single conversion, so that only a single conversion will take place before
 128                          *  the ADC returns to idle.
 129                          */
 130                         #define ADC_SINGLE_CONVERSION           (0 << ADATE)
 131                         //@}
 132
 133                         /** \name ADC Prescaler Configuration Masks */
 134                         //@{
 135                         /** Sets the ADC input clock to prescale by a factor of 2 the AVR's system clock. */
 136                         #define ADC_PRESCALE_2                  (1 << ADPS0)
 137
 138                         /** Sets the ADC input clock to prescale by a factor of 4 the AVR's system clock. */
 139                         #define ADC_PRESCALE_4                  (1 << ADPS1)
 140
 141                         /** Sets the ADC input clock to prescale by a factor of 8 the AVR's system clock. */
 142                         #define ADC_PRESCALE_8                  ((1 << ADPS0) | (1 << ADPS1))
 143
 144                         /** Sets the ADC input clock to prescale by a factor of 16 the AVR's system clock. */
 145                         #define ADC_PRESCALE_16                 (1 << ADPS2)
 146
 147                         /** Sets the ADC input clock to prescale by a factor of 32 the AVR's system clock. */
 148                         #define ADC_PRESCALE_32                 ((1 << ADPS2) | (1 << ADPS0))
 149
 150                         /** Sets the ADC input clock to prescale by a factor of 64 the AVR's system clock. */
 151                         #define ADC_PRESCALE_64                 ((1 << ADPS2) | (1 << ADPS1))
 152
 153                         /** Sets the ADC input clock to prescale by a factor of 128 the AVR's system clock. */
 154                         #define ADC_PRESCALE_128                ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
 155                         //@}
 156
 157                         /** \name ADC MUX Masks */
 158                         //@{
 159                         /** MUX mask define for the ADC0 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 160                         #define ADC_CHANNEL0                    (0x00 << MUX0)
 161
 162                         /** MUX mask define for the ADC1 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 163                         #define ADC_CHANNEL1                    (0x01 << MUX0)
 164
 165                         #if !(defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 166                                 /** MUX mask define for the ADC2 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 167                                  *
 168                                  *  \note Not available on all AVR models.
 169                                  */
 170                                 #define ADC_CHANNEL2                (0x02 << MUX0)
 171
 172                                 /** MUX mask define for the ADC3 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 173                                  *
 174                                  *  \note Not available on all AVR models.
 175                                  */
 176                                 #define ADC_CHANNEL3                (0x03 << MUX0)
 177                         #endif
 178
 179                         /** MUX mask define for the ADC4 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 180                         #define ADC_CHANNEL4                    (0x04 << MUX0)
 181
 182                         /** MUX mask define for the ADC5 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 183                         #define ADC_CHANNEL5                    (0x05 << MUX0)
 184
 185                         /** MUX mask define for the ADC6 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 186                         #define ADC_CHANNEL6                    (0x06 << MUX0)
 187
 188                         /** MUX mask define for the ADC7 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 189                         #define ADC_CHANNEL7                    (0x07 << MUX0)
 190
 191                         /** MUX mask define for the internal 1.1V bandgap channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 192                         #define ADC_1100MV_BANDGAP              (0x1E << MUX0)
 193
 194                         #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 195                                 /** MUX mask define for the ADC8 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 196                                  *
 197                                  *  \note Not available on all AVR models.
 198                                  */
 199                                 #define ADC_CHANNEL8                ((1 << 8) | (0x00 << MUX0))
 200
 201                                 /** MUX mask define for the ADC9 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 202                                  *
 203                                  *  \note Not available on all AVR models.
 204                                  */
 205                                 #define ADC_CHANNEL9                ((1 << 8) | (0x01 << MUX0))
 206
 207                                 /** MUX mask define for the ADC10 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 208                                  *
 209                                  *  \note Not available on all AVR models.
 210                                  */
 211                                 #define ADC_CHANNEL10               ((1 << 8) | (0x02 << MUX0))
 212
 213                                 /** MUX mask define for the ADC11 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 214                                  *
 215                                  *  \note Not available on all AVR models.
 216                                  */
 217                                 #define ADC_CHANNEL11               ((1 << 8) | (0x03 << MUX0))
 218
 219                                 /** MUX mask define for the ADC12 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 220                                  *
 221                                  *  \note Not available on all AVR models.
 222                                  */
 223                                 #define ADC_CHANNEL12               ((1 << 8) | (0x04 << MUX0))
 224
 225                                 /** MUX mask define for the ADC13 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 226                                  *
 227                                  *  \note Not available on all AVR models.
 228                                  */
 229                                 #define ADC_CHANNEL13               ((1 << 8) | (0x05 << MUX0))
 230
 231                                 /** MUX mask define for the internal temperature sensor channel of the ADC. See \ref ADC_StartReading and
 232                                  *  \ref ADC_GetChannelReading.
 233                                  *
 234                                  *  \note Not available on all AVR models.
 235                                  */
 236                                 #define ADC_INT_TEMP_SENS           ((1 << 8) | (0x07 << MUX0))
 237                         #endif
 238                         //@}
 239
 240                 /* Inline Functions: */
 241                         /** Configures the given ADC channel, ready for ADC conversions. This function sets the
 242                          *  associated port pin as an input and disables the digital portion of the I/O to reduce
 243                          *  power consumption.
 244                          *
 245                          *  \note This must only be called for ADC channels with are connected to a physical port
 246                          *        pin of the AVR, denoted by its special alternative function ADCx.
 247                          *        \n\n
 248                          *
 249                          *  \note The channel number must be specified as an integer, and NOT a ADC_CHANNELx mask.
 250                          *
 251                          *  \param[in] ChannelIndex  ADC channel number to set up for conversions.
 252                          */
 253                         static inline void ADC_SetupChannel(const uint8_t ChannelIndex)
 254                         {
 255                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 256                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
 257                                          defined(__AVR_ATmega32U6__))
 258                                 DDRF  &= ~(1 << ChannelIndex);
 259                                 DIDR0 |=  (1 << ChannelIndex);
 260                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 261                                 if (ChannelIndex < 8)
 262                                 {
 263                                         DDRF  &= ~(1 << ChannelIndex);
 264                                         DIDR0 |=  (1 << ChannelIndex);
 265                                 }
 266                                 else if (ChannelIndex == 8)
 267                                 {
 268                                         DDRD  &= ~(1 << 4);
 269                                         DIDR2 |=  (1 << 0);
 270                                 }
 271                                 else if (ChannelIndex < 11)
 272                                 {
 273                                         DDRD  &= ~(1 << (ChannelIndex - 3));
 274                                         DIDR2 |=  (1 << (ChannelIndex - 8));
 275                                 }
 276                                 else
 277                                 {
 278                                         DDRB  &= ~(1 << (ChannelIndex - 7));
 279                                         DIDR2 |=  (1 << (ChannelIndex - 8));
 280                                 }
 281                                 #endif
 282                         }
 283
 284                         /** De-configures the given ADC channel, re-enabling digital I/O mode instead of analog. This
 285                          *  function sets the associated port pin as an input and re-enabled the digital portion of
 286                          *  the I/O.
 287                          *
 288                          *  \note This must only be called for ADC channels with are connected to a physical port
 289                          *        pin of the AVR, denoted by its special alternative function ADCx.
 290                          *        \n\n
 291                          *
 292                          *  \note The channel number must be specified as an integer, and NOT a ADC_CHANNELx mask.
 293                          *
 294                          *  \param[in] ChannelIndex  ADC channel number to set up for conversions.
 295                          */
 296                         static inline void ADC_DisableChannel(const uint8_t ChannelIndex)
 297                         {
 298                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 299                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
 300                                          defined(__AVR_ATmega32U6__))
 301                                 DDRF  &= ~(1 << ChannelIndex);
 302                                 DIDR0 &= ~(1 << ChannelIndex);
 303                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 304                                 if (ChannelIndex < 8)
 305                                 {
 306                                         DDRF  &= ~(1 << ChannelIndex);
 307                                         DIDR0 &= ~(1 << ChannelIndex);
 308                                 }
 309                                 else if (ChannelIndex == 8)
 310                                 {
 311                                         DDRD  &= ~(1 << 4);
 312                                         DIDR2 &= ~(1 << 0);
 313                                 }
 314                                 else if (ChannelIndex < 11)
 315                                 {
 316                                         DDRD  &= ~(1 << (ChannelIndex - 3));
 317                                         DIDR2 &= ~(1 << (ChannelIndex - 8));
 318                                 }
 319                                 else
 320                                 {
 321                                         DDRB  &= ~(1 << (ChannelIndex - 7));
 322                                         DIDR2 &= ~(1 << (ChannelIndex - 8));
 323                                 }
 324                                 #endif
 325                         }
 326
 327                         /** Starts the reading of the given channel, but does not wait until the conversion has completed.
 328                          *  Once executed, the conversion status can be determined via the \ref ADC_IsReadingComplete() macro and
 329                          *  the result read via the \ref ADC_GetResult() macro.
 330                          *
 331                          *  If the ADC has been initialized in free running mode, calling this function once will begin the repeated
 332                          *  conversions. If the ADC is in single conversion mode (or the channel to convert from is to be changed),
 333                          *  this function must be called each time a conversion is to take place.
 334                          *
 335                          *  \param[in] MUXMask  ADC channel mask, reference mask and adjustment mask.
 336                          */
 337                         static inline void ADC_StartReading(const uint16_t MUXMask)
 338                         {
 339                                 ADMUX = MUXMask;
 340
 341                                 #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 342                                 if (MUXMask & (1 << 8))
 343                                   ADCSRB |=  (1 << MUX5);
 344                                 else
 345                                   ADCSRB &= ~(1 << MUX5);
 346                                 #endif
 347
 348                                 ADCSRA |= (1 << ADSC);
 349                         }
 350
 351                         /** Indicates if the current ADC conversion is completed, or still in progress.
 352                          *
 353                          *  \return Boolean false if the reading is still taking place, or true if the conversion is
 354                          *          complete and ready to be read out with \ref ADC_GetResult().
 355                          */
 356                         static inline bool ADC_IsReadingComplete(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 357                         static inline bool ADC_IsReadingComplete(void)
 358                         {
 359                                 return ((ADCSRA & (1 << ADIF)) ? true : false);
 360                         }
 361
 362                         /** Retrieves the conversion value of the last completed ADC conversion and clears the reading
 363                          *  completion flag.
 364                          *
 365                          *  \return The result of the last ADC conversion as an unsigned value.
 366                          */
 367                         static inline uint16_t ADC_GetResult(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 368                         static inline uint16_t ADC_GetResult(void)
 369                         {
 370                                 ADCSRA |= (1 << ADIF);
 371                                 return ADC;
 372                         }
 373
 374                         /** Performs a complete single reading from channel, including a polling spin-loop to wait for the
 375                          *  conversion to complete, and the returning of the converted value.
 376                          *
 377                          *  \note For free running mode, the automated conversions should be initialized with a single call
 378                          *        to \ref ADC_StartReading() to select the channel and begin the automated conversions, and
 379                          *        the results read directly from the \ref ADC_GetResult() instead to reduce overhead.
 380                          *
 381                          *  \param[in] MUXMask  Mask comprising of an ADC channel mask, reference mask and adjustment mask.
 382                          */
 383                         static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask) ATTR_WARN_UNUSED_RESULT;
 384                         static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask)
 385                         {
 386                                 ADC_StartReading(MUXMask);
 387
 388                                 while (!(ADC_IsReadingComplete()));
 389
 390                                 return ADC_GetResult();
 391                         }
 392
 393                         /** Initialises the ADC, ready for conversions. This must be called before any other ADC operations.
 394                          *  The "mode" parameter should be a mask comprised of a conversion mode (free running or single) and
 395                          *  prescaler masks.
 396                          *
 397                          *  \param[in] Mode  Mask of ADC prescale and mode settings.
 398                          */
 399                         static inline void ADC_Init(uint8_t Mode) ATTR_ALWAYS_INLINE;
 400                         static inline void ADC_Init(uint8_t Mode)
 401                         {
 402                                 ADCSRA = ((1 << ADEN) | Mode);
 403                         }
 404
 405                         /** Turns off the ADC. If this is called, any further ADC operations will require a call to
 406                          *  \ref ADC_Init() before the ADC can be used again.
 407                          */
 408                         static inline void ADC_ShutDown(void) ATTR_ALWAYS_INLINE;
 409                         static inline void ADC_ShutDown(void)
 410                         {
 411                                 ADCSRA = 0;
 412                         }
 413
 414                         /** Indicates if the ADC is currently enabled.
 415                          *
 416                          *  \return Boolean true if the ADC subsystem is currently enabled, false otherwise.
 417                          */
 418                         static inline bool ADC_GetStatus(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 419                         static inline bool ADC_GetStatus(void)
 420                         {
 421                                 return ((ADCSRA & (1 << ADEN)) ? true : false);
 422                         }
 423
 424         /* Disable C linkage for C++ Compilers: */
 425                 #if defined(__cplusplus)
 426                         }
 427                 #endif
 428
 429 #endif
 430
 431 /** @} */
 432