LUFA/Drivers/Peripheral/AVR8/ADC.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   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  *
  33  *  ADC driver for the 8-Bit AVRs containing a hardware ADC module.
  34  *
  35  *  \note This file should not be included directly. It is automatically included as needed by the ADC driver
  36  *        dispatch header located in LUFA/Drivers/Peripheral/ADC.h.
  37  */
  38
  39 /** \ingroup Group_ADC
  40  *  @defgroup Group_ADC_AVR8 8-Bit AVR ADC Driver
  41  *
  42  *  ADC driver for 8-Bit AVRs containing a hardware ADC module.
  43  *
  44  *  \note This file should not be included directly. It is automatically included as needed by the ADC driver
  45  *        dispatch header located in LUFA/Drivers/Peripheral/ADC.h.
  46  *
  47  *  @{
  48  */
  49
  50 #ifndef __ADC_AVR8_H__
  51 #define __ADC_AVR8_H__
  52
  53         /* Includes: */
  54                 #include <avr/io.h>
  55                 #include <stdbool.h>
  56
  57         /* Enable C linkage for C++ Compilers: */
  58                 #if defined(__cplusplus)
  59                         extern "C" {
  60                 #endif
  61
  62         /* Preprocessor Checks: */
  63                 #if !defined(__INCLUDE_FROM_ADC_H)
  64                         #error Do not include this file directly. Include LUFA/Drivers/Peripheral/ADC.h instead.
  65                 #endif
  66
  67         /* Public Interface - May be used in end-application: */
  68                 /* Macros: */
  69                         /** Reference mask, for using the voltage present at the AVR's AREF pin for the ADC reference. */
  70                         #define  ADC_REFERENCE_AREF              0
  71
  72                         /** Reference mask, for using the voltage present at the AVR's AVCC pin for the ADC reference. */
  73                         #define  ADC_REFERENCE_AVCC              (1 << REFS0)
  74
  75                         /** Reference mask, for using the internally generated 2.56V reference voltage as the ADC reference. */
  76                         #define  ADC_REFERENCE_INT2560MV         ((1 << REFS1)| (1 << REFS0))
  77
  78                         /** Left-adjusts the 10-bit ADC result, so that the upper 8 bits of the value returned by the
  79                          *  ADC_GetResult() macro contain the 8 most significant bits of the result. */
  80                         #define  ADC_LEFT_ADJUSTED               (1 << ADLAR)
  81
  82                         /** Right-adjusts the 10-bit ADC result, so that the lower 8 bits of the value returned by the
  83                          *  ADC_GetResult() macro contain the 8 least significant bits of the result. */
  84                         #define  ADC_RIGHT_ADJUSTED              (0 << ADLAR)
  85
  86                         /** Sets the ADC mode to free running, so that conversions take place continuously as fast as the ADC
  87                          *  is capable of at the given input clock speed. */
  88                         #define  ADC_FREE_RUNNING                (1 << ADATE)
  89
  90                         /** Sets the ADC mode to single conversion, so that only a single conversion will take place before
  91                          *  the ADC returns to idle. */
  92                         #define  ADC_SINGLE_CONVERSION           (0 << ADATE)
  93
  94                         /** Sets the ADC input clock to prescale by a factor of 2 the AVR's system clock. */
  95                         #define  ADC_PRESCALE_2                  (1 << ADPS0)
  96
  97                         /** Sets the ADC input clock to prescale by a factor of 4 the AVR's system clock. */
  98                         #define  ADC_PRESCALE_4                  (1 << ADPS1)
  99
 100                         /** Sets the ADC input clock to prescale by a factor of 8 the AVR's system clock. */
 101                         #define  ADC_PRESCALE_8                  ((1 << ADPS0) | (1 << ADPS1))
 102
 103                         /** Sets the ADC input clock to prescale by a factor of 16 the AVR's system clock. */
 104                         #define  ADC_PRESCALE_16                 (1 << ADPS2)
 105
 106                         /** Sets the ADC input clock to prescale by a factor of 32 the AVR's system clock. */
 107                         #define  ADC_PRESCALE_32                 ((1 << ADPS2) | (1 << ADPS0))
 108
 109                         /** Sets the ADC input clock to prescale by a factor of 64 the AVR's system clock. */
 110                         #define  ADC_PRESCALE_64                 ((1 << ADPS2) | (1 << ADPS1))
 111
 112                         /** Sets the ADC input clock to prescale by a factor of 128 the AVR's system clock. */
 113                         #define  ADC_PRESCALE_128                ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
 114
 115                         //@{
 116                         /** MUX mask define for the ADC0 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 117                         #define  ADC_CHANNEL0                    0x00
 118
 119                         /** MUX mask define for the ADC1 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 120                         #define  ADC_CHANNEL1                    0x01
 121
 122                         #if !(defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 123                                 /** MUX mask define for the ADC2 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 124                                  *
 125                                  *  \note Note available on all AVR models.
 126                                  */
 127                                 #define  ADC_CHANNEL2                    0x02
 128
 129                                 /** MUX mask define for the ADC3 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 130                                  *
 131                                  *  \note Note available on all AVR models.
 132                                  */
 133                                 #define  ADC_CHANNEL3                    0x03
 134                         #endif
 135
 136                         /** MUX mask define for the ADC4 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 137                         #define  ADC_CHANNEL4                    0x04
 138
 139                         /** MUX mask define for the ADC5 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 140                         #define  ADC_CHANNEL5                    0x05
 141
 142                         /** MUX mask define for the ADC6 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 143                         #define  ADC_CHANNEL6                    0x06
 144
 145                         /** MUX mask define for the ADC7 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 146                         #define  ADC_CHANNEL7                    0x07
 147
 148                         /** MUX mask define for the internal 1.1V bandgap channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
 149                         #define  ADC_1100MV_BANDGAP              0x1E
 150
 151                         #if (defined(__AVR_ATmega16U4__)  || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
 152                                 /** MUX mask define for the ADC8 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 153                                  *
 154                                  *  \note Note available on all AVR models.
 155                                  */
 156                                 #define  ADC_CHANNEL8                0x20
 157
 158                                 /** MUX mask define for the ADC9 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 159                                  *
 160                                  *  \note Note available on all AVR models.
 161                                  */
 162                                 #define  ADC_CHANNEL9                0x21
 163
 164                                 /** MUX mask define for the ADC10 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 165                                  *
 166                                  *  \note Note available on all AVR models.
 167                                  */
 168                                 #define  ADC_CHANNEL10               0x22
 169
 170                                 /** MUX mask define for the ADC11 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 171                                  *
 172                                  *  \note Note available on all AVR models.
 173                                  */
 174                                 #define  ADC_CHANNEL11               0x23
 175
 176                                 /** MUX mask define for the ADC12 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 177                                  *
 178                                  *  \note Note available on all AVR models.
 179                                  */
 180                                 #define  ADC_CHANNEL12               0x24
 181
 182                                 /** MUX mask define for the ADC13 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading.
 183                                  *
 184                                  *  \note Note available on all AVR models.
 185                                  */
 186                                 #define  ADC_CHANNEL13               0x25
 187
 188                                 /** MUX mask define for the internal temperature sensor channel of the ADC. See \ref ADC_StartReading and
 189                                  *  \ref ADC_GetChannelReading.
 190                                  *
 191                                  *  \note Note available on all AVR models.
 192                                  */
 193                                 #define  ADC_INT_TEMP_SENS           0x27
 194                         #endif
 195                         //@}
 196
 197                 /* Pseudo-Function Macros: */
 198                         #if defined(__DOXYGEN__)
 199                                 /** Initializes the ADC, ready for conversions. This must be called before any other ADC operations.
 200                                  *  The "mode" parameter should be a mask comprised of a conversion mode (free running or single) and
 201                                  *  prescaler masks.
 202                                  *
 203                                  *  \param[in] Mode  Mask of ADC settings, including adjustment, prescale, mode and reference
 204                                  */
 205                                 static inline void ADC_Init(uint8_t Mode);
 206
 207                                 /** Turns off the ADC. If this is called, any further ADC operations will require a call to
 208                                  *  \ref ADC_Init() before the ADC can be used again.
 209                                  */
 210                                 static inline void ADC_ShutDown(void);
 211
 212                                 /** Indicates if the ADC is currently enabled.
 213                                  *
 214                                  *  \return Boolean true if the ADC subsystem is currently enabled, false otherwise.
 215                                  */
 216                                 static inline bool ADC_GetStatus(void);
 217
 218                                 /** Indicates if the current ADC conversion is completed, or still in progress.
 219                                  *
 220                                  *  \return Boolean false if the reading is still taking place, or true if the conversion is
 221                                  *          complete and ready to be read out with \ref ADC_GetResult()
 222                                  */
 223                                 static inline bool ADC_IsReadingComplete(void);
 224
 225                                 /** Retrieves the conversion value of the last completed ADC conversion.
 226                                  *
 227                                  *  \return The result of the last ADC conversion
 228                                  */
 229                                 static inline uint16_t ADC_GetResult(void);
 230                         #else
 231                                 #define  ADC_Init(mode)          MACROS{ ADCSRA = ((1 << ADEN) | mode);         }MACROE
 232
 233                                 #define  ADC_ShutDown()          MACROS{ ADCSRA = 0;                            }MACROE
 234
 235                                 #define  ADC_GetStatus()               ((ADCSRA & (1 << ADEN)) ? true : false)
 236
 237                                 #define  ADC_IsReadingComplete()        (ADCSRA & (1 << ADSC))
 238
 239                                 #define  ADC_GetResult()                 ADC
 240                         #endif
 241
 242                 /* Inline Functions: */
 243                         /** Configures the given ADC channel, ready for ADC conversions. This function sets the
 244                          *  associated port pin as an input and disables the digital portion of the I/O to reduce
 245                          *  power consumption.
 246                          *
 247                          *  \note This must only be called for ADC channels with are connected to a physical port
 248                          *        pin of the AVR, denoted by its special alternative function ADCx.
 249                          *
 250                          *  \note The channel number must be specified as an integer, and NOT a ADC_CHANNELx mask.
 251                          *
 252                          *  \param[in] Channel  ADC channel number to set up for conversions
 253                          */
 254                         static inline void ADC_SetupChannel(const uint8_t Channel)
 255                         {
 256                                 #if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
 257                                          defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
 258                                          defined(__AVR_ATmega32U6__))
 259                                 DDRF  &= ~(1 << Channel);
 260                                 DIDR0 |=  (1 << Channel);
 261                                 #elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
 262                                 if (Channel < 8)
 263                                 {
 264                                         DDRF  &= ~(1 << Channel);
 265                                         DIDR0 |=  (1 << Channel);
 266                                 }
 267                                 else if (Channel == 8)
 268                                 {
 269                                         DDRD  &= ~(1 << 4);
 270                                         DIDR2 |=  (1 << 0);
 271                                 }
 272                                 else if (Channel < 11)
 273                                 {
 274                                         DDRD  &= ~(1 << (Channel - 3));
 275                                         DIDR2 |=  (1 << (Channel - 8));
 276                                 }
 277                                 else
 278                                 {
 279                                         DDRB  &= ~(1 << (Channel - 7));
 280                                         DIDR2 |=  (1 << (Channel - 8));
 281                                 }
 282                                 #endif
 283                         }
 284
 285                         /** Starts the reading of the given channel, but does not wait until the conversion has completed.
 286                          *  Once executed, the conversion status can be determined via the \ref ADC_IsReadingComplete() macro and
 287                          *  the result read via the \ref ADC_GetResult() macro.
 288                          *
 289                          *  \param[in] MUXMask  Mask comprising of an ADC channel mask, reference mask and adjustment mask
 290                          */
 291                         static inline void ADC_StartReading(const uint8_t MUXMask)
 292                         {
 293                                 ADMUX = MUXMask;
 294
 295                                 ADCSRA |= (1 << ADSC);
 296                         }
 297
 298                         /** Performs a complete single reading from channel, including a polling spin-loop to wait for the
 299                          *  conversion to complete, and the returning of the converted value.
 300                          *
 301                          *  \param[in] MUXMask  Mask comprising of an ADC channel mask, reference mask and adjustment mask
 302                          */
 303                         static inline uint16_t ADC_GetChannelReading(const uint8_t MUXMask) ATTR_WARN_UNUSED_RESULT;
 304                         static inline uint16_t ADC_GetChannelReading(const uint8_t MUXMask)
 305                         {
 306                                 ADC_StartReading(MUXMask);
 307
 308                                 while (!(ADC_IsReadingComplete()));
 309
 310                                 return ADC_GetResult();
 311                         }
 312
 313         /* Disable C linkage for C++ Compilers: */
 314                 #if defined(__cplusplus)
 315                         }
 316                 #endif
 317
 318 #endif
 319
 320 /** @} */