ADC_AVR8.h
17.1 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
/*
LUFA Library
Copyright (C) Dean Camera, 2017.
dean [at] fourwalledcubicle [dot] com
www.lufa-lib.org
*/
/*
Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com)
Permission to use, copy, modify, distribute, and sell this
software and its documentation for any purpose is hereby granted
without fee, provided that the above copyright notice appear in
all copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the name of the author not be used in
advertising or publicity pertaining to distribution of the
software without specific, written prior permission.
The author disclaims all warranties with regard to this
software, including all implied warranties of merchantability
and fitness. In no event shall the author be liable for any
special, indirect or consequential damages or any damages
whatsoever resulting from loss of use, data or profits, whether
in an action of contract, negligence or other tortious action,
arising out of or in connection with the use or performance of
this software.
*/
/** \file
* \brief ADC Peripheral Driver (AVR8)
*
* On-chip Analogue-to-Digital converter (ADC) driver for supported U4, U6 and U7 model AVRs that contain an ADC
* peripheral internally.
*
* \note This file should not be included directly. It is automatically included as needed by the ADC driver
* dispatch header located in LUFA/Drivers/Peripheral/ADC.h.
*/
/** \ingroup Group_ADC
* \defgroup Group_ADC_AVR8 ADC Peripheral Driver (AVR8)
*
* \section Sec_ADC_AVR8_ModDescription Module Description
* On-chip Analogue-to-Digital converter (ADC) driver for supported U4, U6 and U7 model AVRs that contain an ADC
* peripheral internally.
*
* \note This file should not be included directly. It is automatically included as needed by the ADC driver
* dispatch header located in LUFA/Drivers/Peripheral/ADC.h.
*
* \section Sec_ADC_AVR8_ExampleUsage Example Usage
* The following snippet is an example of how this module may be used within a typical
* application.
*
* \code
* // Initialize the ADC driver before first use
* ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
*
* // Must setup the ADC channel to read beforehand
* ADC_SetupChannel(1);
*
* // Perform a single conversion of the ADC channel 1
* ADC_GetChannelReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | ADC_CHANNEL1);
* printf("Conversion Result: %d\r\n", ADC_GetResult());
*
* // Start reading ADC channel 1 in free running (continuous conversion) mode
* ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | ADC_CHANNEL1);
* for (;;)
* {
* while (!(ADC_IsReadingComplete())) {};
* printf("Conversion Result: %d\r\n", ADC_GetResult());
* }
* \endcode
*
* @{
*/
#ifndef __ADC_AVR8_H__
#define __ADC_AVR8_H__
/* Includes: */
#include "../../../Common/Common.h"
/* Enable C linkage for C++ Compilers: */
#if defined(__cplusplus)
extern "C" {
#endif
/* Preprocessor Checks: */
#if !defined(__INCLUDE_FROM_ADC_H)
#error Do not include this file directly. Include LUFA/Drivers/Peripheral/ADC.h instead.
#endif
#if !(defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
#error The ADC peripheral driver is not currently available for your selected microcontroller model.
#endif
/* Public Interface - May be used in end-application: */
/* Macros: */
/** \name ADC Reference Configuration Masks */
//@{
/** Reference mask, for using the voltage present at the AVR's AREF pin for the ADC reference. */
#define ADC_REFERENCE_AREF 0
/** Reference mask, for using the voltage present at the AVR's AVCC pin for the ADC reference. */
#define ADC_REFERENCE_AVCC (1 << REFS0)
/** Reference mask, for using the internally generated 2.56V reference voltage as the ADC reference. */
#define ADC_REFERENCE_INT2560MV ((1 << REFS1) | (1 << REFS0))
//@}
/** \name ADC Result Adjustment Configuration Masks */
//@{
/** Left-adjusts the 10-bit ADC result, so that the upper 8 bits of the value returned by the
* \ref ADC_GetResult() macro contain the 8 most significant bits of the result.
*/
#define ADC_LEFT_ADJUSTED (1 << ADLAR)
/** Right-adjusts the 10-bit ADC result, so that the lower 8 bits of the value returned by the
* \ref ADC_GetResult() macro contain the 8 least significant bits of the result.
*/
#define ADC_RIGHT_ADJUSTED (0 << ADLAR)
//@}
/** \name ADC Mode Configuration Masks */
//@{
/** Sets the ADC mode to free running, so that conversions take place continuously as fast as the ADC
* is capable of at the given input clock speed.
*/
#define ADC_FREE_RUNNING (1 << ADATE)
/** Sets the ADC mode to single conversion, so that only a single conversion will take place before
* the ADC returns to idle.
*/
#define ADC_SINGLE_CONVERSION (0 << ADATE)
//@}
/** \name ADC Prescaler Configuration Masks */
//@{
/** Sets the ADC input clock to prescale by a factor of 2 the AVR's system clock. */
#define ADC_PRESCALE_2 (1 << ADPS0)
/** Sets the ADC input clock to prescale by a factor of 4 the AVR's system clock. */
#define ADC_PRESCALE_4 (1 << ADPS1)
/** Sets the ADC input clock to prescale by a factor of 8 the AVR's system clock. */
#define ADC_PRESCALE_8 ((1 << ADPS0) | (1 << ADPS1))
/** Sets the ADC input clock to prescale by a factor of 16 the AVR's system clock. */
#define ADC_PRESCALE_16 (1 << ADPS2)
/** Sets the ADC input clock to prescale by a factor of 32 the AVR's system clock. */
#define ADC_PRESCALE_32 ((1 << ADPS2) | (1 << ADPS0))
/** Sets the ADC input clock to prescale by a factor of 64 the AVR's system clock. */
#define ADC_PRESCALE_64 ((1 << ADPS2) | (1 << ADPS1))
/** Sets the ADC input clock to prescale by a factor of 128 the AVR's system clock. */
#define ADC_PRESCALE_128 ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
//@}
/** \name ADC MUX Masks */
//@{
/** MUX mask define for the ADC0 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
#define ADC_CHANNEL0 (0x00 << MUX0)
/** MUX mask define for the ADC1 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
#define ADC_CHANNEL1 (0x01 << MUX0)
#if (!(defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)) || defined(__DOXYGEN__))
/** MUX mask define for the ADC2 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
*
* \note Not available on all AVR models.
*/
#define ADC_CHANNEL2 (0x02 << MUX0)
/** MUX mask define for the ADC3 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
*
* \note Not available on all AVR models.
*/
#define ADC_CHANNEL3 (0x03 << MUX0)
#endif
/** MUX mask define for the ADC4 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
#define ADC_CHANNEL4 (0x04 << MUX0)
/** MUX mask define for the ADC5 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
#define ADC_CHANNEL5 (0x05 << MUX0)
/** MUX mask define for the ADC6 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
#define ADC_CHANNEL6 (0x06 << MUX0)
/** MUX mask define for the ADC7 channel of the ADC. See \ref ADC_StartReading and \ref ADC_GetChannelReading. */
#define ADC_CHANNEL7 (0x07 << MUX0)
#if (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
/** MUX mask define for the ADC8 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
*
* \note Not available on all AVR models.
*/
#define ADC_CHANNEL8 ((1 << 8) | (0x00 << MUX0))
/** MUX mask define for the ADC9 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
*
* \note Not available on all AVR models.
*/
#define ADC_CHANNEL9 ((1 << 8) | (0x01 << MUX0))
/** MUX mask define for the ADC10 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
*
* \note Not available on all AVR models.
*/
#define ADC_CHANNEL10 ((1 << 8) | (0x02 << MUX0))
/** MUX mask define for the ADC11 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
*
* \note Not available on all AVR models.
*/
#define ADC_CHANNEL11 ((1 << 8) | (0x03 << MUX0))
/** MUX mask define for the ADC12 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
*
* \note Not available on all AVR models.
*/
#define ADC_CHANNEL12 ((1 << 8) | (0x04 << MUX0))
/** MUX mask define for the ADC13 channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading().
*
* \note Not available on all AVR models.
*/
#define ADC_CHANNEL13 ((1 << 8) | (0x05 << MUX0))
/** MUX mask define for the internal temperature sensor channel of the ADC. See \ref ADC_StartReading() and
* \ref ADC_GetChannelReading().
*
* \note Not available on all AVR models.
*/
#define ADC_INT_TEMP_SENS ((1 << 8) | (0x07 << MUX0))
#endif
/** MUX mask define for the internal 1.1V band-gap channel of the ADC. See \ref ADC_StartReading() and \ref ADC_GetChannelReading(). */
#define ADC_1100MV_BANDGAP (0x1E << MUX0)
/** Retrieves the ADC MUX mask for the given ADC channel number.
*
* \attention This macro will only work correctly on channel numbers that are compile-time
* constants defined by the preprocessor.
*
* \param[in] Channel Index of the ADC channel whose MUX mask is to be retrieved.
*/
#define ADC_GET_CHANNEL_MASK(Channel) CONCAT_EXPANDED(ADC_CHANNEL, Channel)
//@}
/* Inline Functions: */
/** Configures the given ADC channel, ready for ADC conversions. This function sets the
* associated port pin as an input and disables the digital portion of the I/O to reduce
* power consumption.
*
* \note This must only be called for ADC channels with are connected to a physical port
* pin of the AVR, denoted by its special alternative function ADCx.
*
* \warning The channel number must be specified as an integer, and <b>not</b> a \c ADC_CHANNEL* mask.
*
* \param[in] ChannelIndex ADC channel number to set up for conversions.
*/
static inline void ADC_SetupChannel(const uint8_t ChannelIndex)
{
#if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__))
DDRF &= ~(1 << ChannelIndex);
DIDR0 |= (1 << ChannelIndex);
#elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
if (ChannelIndex < 8)
{
DDRF &= ~(1 << ChannelIndex);
DIDR0 |= (1 << ChannelIndex);
}
else if (ChannelIndex == 8)
{
DDRD &= ~(1 << 4);
DIDR2 |= (1 << 0);
}
else if (ChannelIndex < 11)
{
DDRD &= ~(1 << (ChannelIndex - 3));
DIDR2 |= (1 << (ChannelIndex - 8));
}
else
{
DDRB &= ~(1 << (ChannelIndex - 7));
DIDR2 |= (1 << (ChannelIndex - 8));
}
#endif
}
/** De-configures the given ADC channel, re-enabling digital I/O mode instead of analog. This
* function sets the associated port pin as an input and re-enabled the digital portion of
* the I/O.
*
* \note This must only be called for ADC channels with are connected to a physical port
* pin of the AVR, denoted by its special alternative function ADCx.
*
* \warning The channel number must be specified as an integer, and <b>not</b> a \c ADC_CHANNEL* mask.
*
* \param[in] ChannelIndex ADC channel number to set up for conversions.
*/
static inline void ADC_DisableChannel(const uint8_t ChannelIndex)
{
#if (defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__))
DDRF &= ~(1 << ChannelIndex);
DIDR0 &= ~(1 << ChannelIndex);
#elif (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
if (ChannelIndex < 8)
{
DDRF &= ~(1 << ChannelIndex);
DIDR0 &= ~(1 << ChannelIndex);
}
else if (ChannelIndex == 8)
{
DDRD &= ~(1 << 4);
DIDR2 &= ~(1 << 0);
}
else if (ChannelIndex < 11)
{
DDRD &= ~(1 << (ChannelIndex - 3));
DIDR2 &= ~(1 << (ChannelIndex - 8));
}
else
{
DDRB &= ~(1 << (ChannelIndex - 7));
DIDR2 &= ~(1 << (ChannelIndex - 8));
}
#endif
}
/** Starts the reading of the given channel, but does not wait until the conversion has completed.
* Once executed, the conversion status can be determined via the \ref ADC_IsReadingComplete() macro and
* the result read via the \ref ADC_GetResult() macro.
*
* If the ADC has been initialized in free running mode, calling this function once will begin the repeated
* conversions. If the ADC is in single conversion mode (or the channel to convert from is to be changed),
* this function must be called each time a conversion is to take place.
*
* \param[in] MUXMask ADC channel mask, reference mask and adjustment mask.
*/
static inline void ADC_StartReading(const uint16_t MUXMask)
{
ADMUX = MUXMask;
#if (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || defined(__DOXYGEN__))
if (MUXMask & (1 << 8))
ADCSRB |= (1 << MUX5);
else
ADCSRB &= ~(1 << MUX5);
#endif
ADCSRA |= (1 << ADSC);
}
/** Indicates if the current ADC conversion is completed, or still in progress.
*
* \return Boolean \c false if the reading is still taking place, or true if the conversion is
* complete and ready to be read out with \ref ADC_GetResult().
*/
static inline bool ADC_IsReadingComplete(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
static inline bool ADC_IsReadingComplete(void)
{
return ((ADCSRA & (1 << ADIF)) ? true : false);
}
/** Retrieves the conversion value of the last completed ADC conversion and clears the reading
* completion flag.
*
* \return The result of the last ADC conversion as an unsigned value.
*/
static inline uint16_t ADC_GetResult(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
static inline uint16_t ADC_GetResult(void)
{
ADCSRA |= (1 << ADIF);
return ADC;
}
/** Performs a complete single reading from channel, including a polling spin-loop to wait for the
* conversion to complete, and the returning of the converted value.
*
* \note For free running mode, the automated conversions should be initialized with a single call
* to \ref ADC_StartReading() to select the channel and begin the automated conversions, and
* the results read directly from the \ref ADC_GetResult() instead to reduce overhead.
*
* \param[in] MUXMask Mask comprising of an ADC channel mask, reference mask and adjustment mask.
*
* \return Converted ADC result for the given ADC channel.
*/
static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask) ATTR_WARN_UNUSED_RESULT;
static inline uint16_t ADC_GetChannelReading(const uint16_t MUXMask)
{
ADC_StartReading(MUXMask);
while (!(ADC_IsReadingComplete()));
return ADC_GetResult();
}
/** Initializes the ADC, ready for conversions. This must be called before any other ADC operations.
* The "mode" parameter should be a mask comprised of a conversion mode (free running or single) and
* prescaler masks.
*
* \param[in] Mode Mask of ADC prescale and mode settings.
*/
static inline void ADC_Init(const uint8_t Mode) ATTR_ALWAYS_INLINE;
static inline void ADC_Init(const uint8_t Mode)
{
ADCSRA = ((1 << ADEN) | Mode);
}
/** Turns off the ADC. If this is called, any further ADC operations will require a call to
* \ref ADC_Init() before the ADC can be used again.
*/
static inline void ADC_Disable(void) ATTR_ALWAYS_INLINE;
static inline void ADC_Disable(void)
{
ADCSRA = 0;
}
/** Indicates if the ADC is currently enabled.
*
* \return Boolean \c true if the ADC subsystem is currently enabled, \c false otherwise.
*/
static inline bool ADC_GetStatus(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
static inline bool ADC_GetStatus(void)
{
return ((ADCSRA & (1 << ADEN)) ? true : false);
}
/* Disable C linkage for C++ Compilers: */
#if defined(__cplusplus)
}
#endif
#endif
/** @} */