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  *  <b>Example Usage:</b>
  51  *  \code
  52  *      // Initialise the ADC driver before first use
  53  *      ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
  54  *
  55  *      // Must setup the ADC channel to read beforehand
  56  *      ADC_SetupChannel(1);
  57  *
  58  *      // Perform a single conversion of the ADC channel 1
  59  *      ADC_GetChannelReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | ADC_CHANNEL1);
  60  *      printf("Conversion Result: %d\r\n", ADC_GetResult());
  61  *
  62  *      // Start reading ADC channel 1 in free running (continuous conversion) mode
  63  *      ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | ADC_CHANNEL1);
  64  *      while (!(ADC_IsReadingComplete())) {};
  65  *      printf("Conversion Result: %d\r\n", ADC_GetResult());
  66  *  \endcode
  67  *
  68  *  @{
  69  */
  70
  71 #ifndef __ADC_AVRU4U6U7_H__
  72 #define __ADC_AVRU4U6U7_H__
  73
  74         /* Includes: */
  75                 #include "../../../Common/Common.h"
  76
  77                 #include <avr/io.h>
  78                 #include <stdbool.h>
  79
  80         /* Enable C linkage for C++ Compilers: */
  81                 #if defined(__cplusplus)
  82                         extern "C" {
  83                 #endif
  84
  85         /* Preprocessor Checks: */
  86                 #if !defined(__INCLUDE_FROM_ADC_H)
  87                         #error Do not include this file directly. Include LUFA/Drivers/Peripheral/ADC.h instead.
  88                 #endif
  89
  90         /* Public Interface - May be used in end-application: */
  91                 /* Macros: */
  92                         /** \name ADC Reference Configuration Masks */
  93                         //@{
  94                         /** Reference mask, for using the voltage present at the AVR's AREF pin for the ADC reference. */
  95                         #define ADC_REFERENCE_AREF              0
  96
  97                         /** Reference mask, for using the voltage present at the AVR's AVCC pin for the ADC reference. */
  98                         #define ADC_REFERENCE_AVCC              (1 << REFS0)
  99
 100                         /** Reference mask, for using the internally generated 2.56V reference voltage as the ADC reference. */
 101                         #define ADC_REFERENCE_INT2560MV         ((1 << REFS1) | (1 << REFS0))
 102                         //@}
 103
 104                         /** \name ADC Result Adjustment Configuration Masks */
 105                         //@{
 106                         /** Left-adjusts the 10-bit ADC result, so that the upper 8 bits of the value returned by the
 107                          *  ADC_GetResult() macro contain the 8 most significant bits of the result.
 108                          */
 109                         #define ADC_LEFT_ADJUSTED               (1 << ADLAR)
 110
 111                         /** Right-adjusts the 10-bit ADC result, so that the lower 8 bits of the value returned by the
 112                          *  ADC_GetResult() macro contain the 8 least significant bits of the result.
 113                          */
 114                         #define ADC_RIGHT_ADJUSTED              (0 << ADLAR)
 115                         //@}
 116
 117                         /** \name ADC Mode Configuration Masks */
 118                         //@{
 119                         /** Sets the ADC mode to free running, so that conversions take place continuously as fast as the ADC
 120                          *  is capable of at the given input clock speed.
 121                          */
 122                         #define ADC_FREE_RUNNING                (1 << ADATE)
 123
 124                         /** Sets the ADC mode to single conversion, so that only a single conversion will take place before
 125                          *  the ADC returns to idle.
 126                          */
 127                         #define ADC_SINGLE_CONVERSION           (0 << ADATE)
 128                         //@}
 129
 130                         /** \name ADC Prescaler Configuration Masks */
 131                         //@{
 132                         /** Sets the ADC input clock to prescale by a factor of 2 the AVR's system clock. */
 133                         #define ADC_PRESCALE_2                  (1 << ADPS0)
 134
 135                         /** Sets the ADC input clock to prescale by a factor of 4 the AVR's system clock. */
 136                         #define ADC_PRESCALE_4                  (1 << ADPS1)
 137
 138                         /** Sets the ADC input clock to prescale by a factor of 8 the AVR's system clock. */
 139                         #define ADC_PRESCALE_8                  ((1 << ADPS0) | (1 << ADPS1))
 140
 141                         /** Sets the ADC input clock to prescale by a factor of 16 the AVR's system clock. */
 142                         #define ADC_PRESCALE_16                 (1 << ADPS2)
 143
 144                         /** Sets the ADC input clock to prescale by a factor of 32 the AVR's system clock. */
 145                         #define ADC_PRESCALE_32                 ((1 << ADPS2) | (1 << ADPS0))
 146
 147                         /** Sets the ADC input clock to prescale by a factor of 64 the AVR's system clock. */
 148                         #define ADC_PRESCALE_64                 ((1 << ADPS2) | (1 << ADPS1))
 149
 150                         /** Sets the ADC input clock to prescale by a factor of 128 the AVR's system clock. */
 151                         #define ADC_PRESCALE_128                ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
 152                         //@}
 153
 154                         /** \name ADC MUX Masks */
 155                         //@{
 156                         /** MUX mask define for the ADC0 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 157                         #define ADC_CHANNEL0                    (0x00 << MUX0)
 158
 159                         /** MUX mask define for the ADC1 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 160                         #define ADC_CHANNEL1                    (0x01 << MUX0)
 161
 162                         #if !(defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 163                                 /** MUX mask define for the ADC2 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 164                                  *
 165                                  *  \note Not available on all AVR models.
 166                                  */
 167                                 #define ADC_CHANNEL2                (0x02 << MUX0)
 168
 169                                 /** MUX mask define for the ADC3 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 170                                  *
 171                                  *  \note Not available on all AVR models.
 172                                  */
 173                                 #define ADC_CHANNEL3                (0x03 << MUX0)
 174                         #endif
 175
 176                         /** MUX mask define for the ADC4 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 177                         #define ADC_CHANNEL4                    (0x04 << MUX0)
 178
 179                         /** MUX mask define for the ADC5 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 180                         #define ADC_CHANNEL5                    (0x05 << MUX0)
 181
 182                         /** MUX mask define for the ADC6 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 183                         #define ADC_CHANNEL6                    (0x06 << MUX0)
 184
 185                         /** MUX mask define for the ADC7 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 186                         #define ADC_CHANNEL7                    (0x07 << MUX0)
 187
 188                         /** MUX mask define for the internal 1.1V bandgap channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 189                         #define ADC_1100MV_BANDGAP              (0x1E << MUX0)
 190
 191                         #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 192                                 /** MUX mask define for the ADC8 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 193                                  *
 194                                  *  \note Not available on all AVR models.
 195                                  */
 196                                 #define ADC_CHANNEL8                ((1 << 8) | (0x00 << MUX0))
 197
 198                                 /** MUX mask define for the ADC9 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 199                                  *
 200                                  *  \note Not available on all AVR models.
 201                                  */
 202                                 #define ADC_CHANNEL9                ((1 << 8) | (0x01 << MUX0))
 203
 204                                 /** MUX mask define for the ADC10 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 205                                  *
 206                                  *  \note Not available on all AVR models.
 207                                  */
 208                                 #define ADC_CHANNEL10               ((1 << 8) | (0x02 << MUX0))
 209
 210                                 /** MUX mask define for the ADC11 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_CHANNEL11               ((1 << 8) | (0x03 << MUX0))
 215
 216                                 /** MUX mask define for the ADC12 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_CHANNEL12               ((1 << 8) | (0x04 << MUX0))
 221
 222                                 /** MUX mask define for the ADC13 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_CHANNEL13               ((1 << 8) | (0x05 << MUX0))
 227
 228                                 /** MUX mask define for the internal temperature sensor channel of the ADC. See \ref ADC_StartReading and
 229                                  *  \ref ADC_GetChannelReading.
 230                                  *
 231                                  *  \note Not available on all AVR models.
 232                                  */
 233                                 #define ADC_INT_TEMP_SENS           ((1 << 8) | (0x07 << MUX0))
 234                         #endif
 235                         //@}
 236
 237                 /* Inline Functions: */
 238                         /** Configures the given ADC channel, ready for ADC conversions. This function sets the
 239                          *  associated port pin as an input and disables the digital portion of the I/O to reduce
 240                          *  power consumption.
 241                          *
 242                          *  \note This must only be called for ADC channels with are connected to a physical port
 243                          *        pin of the AVR, denoted by its special alternative function ADCx.
 244                          *        \n\n
 245                          *
 246                          *  \note The channel number must be specified as an integer, and NOT a ADC_CHANNELx mask.
 247                          *
 248                          *  \param[in] ChannelIndex  ADC channel number to set up for conversions.
 249                          */
 250                         static inline void ADC_SetupChannel(const uint8_t ChannelIndex)
 251                         {
 252                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 253                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
 254                                          defined(__AVR_ATmega32U6__))
 255                                 DDRF  &= ~(1 << ChannelIndex);
 256                                 DIDR0 |=  (1 << ChannelIndex);
 257                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 258                                 if (ChannelIndex < 8)
 259                                 {
 260                                         DDRF  &= ~(1 << ChannelIndex);
 261                                         DIDR0 |=  (1 << ChannelIndex);
 262                                 }
 263                                 else if (ChannelIndex == 8)
 264                                 {
 265                                         DDRD  &= ~(1 << 4);
 266                                         DIDR2 |=  (1 << 0);
 267                                 }
 268                                 else if (ChannelIndex < 11)
 269                                 {
 270                                         DDRD  &= ~(1 << (ChannelIndex - 3));
 271                                         DIDR2 |=  (1 << (ChannelIndex - 8));
 272                                 }
 273                                 else
 274                                 {
 275                                         DDRB  &= ~(1 << (ChannelIndex - 7));
 276                                         DIDR2 |=  (1 << (ChannelIndex - 8));
 277                                 }
 278                                 #endif
 279                         }
 280
 281                         /** De-configures the given ADC channel, re-enabling digital I/O mode instead of analog. This
 282                          *  function sets the associated port pin as an input and re-enabled the digital portion of
 283                          *  the I/O.
 284                          *
 285                          *  \note This must only be called for ADC channels with are connected to a physical port
 286                          *        pin of the AVR, denoted by its special alternative function ADCx.
 287                          *        \n\n
 288                          *
 289                          *  \note The channel number must be specified as an integer, and NOT a ADC_CHANNELx mask.
 290                          *
 291                          *  \param[in] ChannelIndex  ADC channel number to set up for conversions.
 292                          */
 293                         static inline void ADC_DisableChannel(const uint8_t ChannelIndex)
 294                         {
 295                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 296                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
 297                                          defined(__AVR_ATmega32U6__))
 298                                 DDRF  &= ~(1 << ChannelIndex);
 299                                 DIDR0 &= ~(1 << ChannelIndex);
 300                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 301                                 if (ChannelIndex < 8)
 302                                 {
 303                                         DDRF  &= ~(1 << ChannelIndex);
 304                                         DIDR0 &= ~(1 << ChannelIndex);
 305                                 }
 306                                 else if (ChannelIndex == 8)
 307                                 {
 308                                         DDRD  &= ~(1 << 4);
 309                                         DIDR2 &= ~(1 << 0);
 310                                 }
 311                                 else if (ChannelIndex < 11)
 312                                 {
 313                                         DDRD  &= ~(1 << (ChannelIndex - 3));
 314                                         DIDR2 &= ~(1 << (ChannelIndex - 8));
 315                                 }
 316                                 else
 317                                 {
 318                                         DDRB  &= ~(1 << (ChannelIndex - 7));
 319                                         DIDR2 &= ~(1 << (ChannelIndex - 8));
 320                                 }
 321                                 #endif
 322                         }
 323
 324                         /** Starts the reading of the given channel, but does not wait until the conversion has completed.
 325                          *  Once executed, the conversion status can be determined via the \ref ADC_IsReadingComplete() macro and
 326                          *  the result read via the \ref ADC_GetResult() macro.
 327                          *
 328                          *  If the ADC has been initialized in free running mode, calling this function once will begin the repeated
 329                          *  conversions. If the ADC is in single conversion mode (or the channel to convert from is to be changed),
 330                          *  this function must be called each time a conversion is to take place.
 331                          *
 332                          *  \param[in] MUXMask  ADC channel mask, reference mask and adjustment mask.
 333                          */
 334                         static inline void ADC_StartReading(const uint16_t MUXMask)
 335                         {
 336                                 ADMUX = MUXMask;
 337
 338                                 #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 339                                 if (MUXMask & (1 << 8))
 340                                   ADCSRB |=  (1 << MUX5);
 341                                 else
 342                                   ADCSRB &= ~(1 << MUX5);
 343                                 #endif
 344
 345                                 ADCSRA |= (1 << ADSC);
 346                         }
 347
 348                         /** Indicates if the current ADC conversion is completed, or still in progress.
 349                          *
 350                          *  \return Boolean false if the reading is still taking place, or true if the conversion is
 351                          *          complete and ready to be read out with \ref ADC_GetResult().
 352                          */
 353                         static inline bool ADC_IsReadingComplete(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 354                         static inline bool ADC_IsReadingComplete(void)
 355                         {
 356                                 return ((ADCSRA & (1 << ADIF)) ? true : false);
 357                         }
 358
 359                         /** Retrieves the conversion value of the last completed ADC conversion and clears the reading
 360                          *  completion flag.
 361                          *
 362                          *  \return The result of the last ADC conversion as an unsigned value.
 363                          */
 364                         static inline uint16_t ADC_GetResult(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 365                         static inline uint16_t ADC_GetResult(void)
 366                         {
 367                                 ADCSRA |= (1 << ADIF);
 368                                 return ADC;
 369                         }
 370
 371                         /** Performs a complete single reading from channel, including a polling spin-loop to wait for the
 372                          *  conversion to complete, and the returning of the converted value.
 373                          *
 374                          *  \note For free running mode, the automated conversions should be initialized with a single call
 375                          *        to \ref ADC_StartReading() to select the channel and begin the automated conversions, and
 376                          *        the results read directly from the \ref ADC_GetResult() instead to reduce overhead.
 377                          *
 378                          *  \param[in] MUXMask  Mask comprising of an ADC channel mask, reference mask and adjustment mask.
 379                          */
 380                         static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask) ATTR_WARN_UNUSED_RESULT;
 381                         static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask)
 382                         {
 383                                 ADC_StartReading(MUXMask);
 384
 385                                 while (!(ADC_IsReadingComplete()));
 386
 387                                 return ADC_GetResult();
 388                         }
 389
 390                         /** Initialises the ADC, ready for conversions. This must be called before any other ADC operations.
 391                          *  The "mode" parameter should be a mask comprised of a conversion mode (free running or single) and
 392                          *  prescaler masks.
 393                          *
 394                          *  \param[in] Mode  Mask of ADC prescale and mode settings.
 395                          */
 396                         static inline void ADC_Init(uint8_t Mode) ATTR_ALWAYS_INLINE;
 397                         static inline void ADC_Init(uint8_t Mode)
 398                         {
 399                                 ADCSRA = ((1 << ADEN) | Mode);
 400                         }
 401
 402                         /** Turns off the ADC. If this is called, any further ADC operations will require a call to
 403                          *  \ref ADC_Init() before the ADC can be used again.
 404                          */
 405                         static inline void ADC_ShutDown(void) ATTR_ALWAYS_INLINE;
 406                         static inline void ADC_ShutDown(void)
 407                         {
 408                                 ADCSRA = 0;
 409                         }
 410
 411                         /** Indicates if the ADC is currently enabled.
 412                          *
 413                          *  \return Boolean true if the ADC subsystem is currently enabled, false otherwise.
 414                          */
 415                         static inline bool ADC_GetStatus(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 416                         static inline bool ADC_GetStatus(void)
 417                         {
 418                                 return ((ADCSRA & (1 << ADEN)) ? true : false);
 419                         }
 420
 421         /* Disable C linkage for C++ Compilers: */
 422                 #if defined(__cplusplus)
 423                         }
 424                 #endif
 425
 426 #endif
 427
 428 /** @} */
 429