BayEOS-Arduino  1.8.0_0.0.4
OneWire.cpp
1 /*
2 Copyright (c) 2007, Jim Studt (original old version - many contributors since)
3 
4 The latest version of this library may be found at:
5  http://www.pjrc.com/teensy/td_libs_OneWire.html
6 
7 OneWire has been maintained by Paul Stoffregen (paul@pjrc.com) since
8 January 2010. At the time, it was in need of many bug fixes, but had
9 been abandoned the original author (Jim Studt). None of the known
10 contributors were interested in maintaining OneWire. Paul typically
11 works on OneWire every 6 to 12 months. Patches usually wait that
12 long. If anyone is interested in more actively maintaining OneWire,
13 please contact Paul.
14 
15 Version 2.3:
16  Unknonw chip fallback mode, Roger Clark
17  Teensy-LC compatibility, Paul Stoffregen
18  Search bug fix, Love Nystrom
19 
20 Version 2.2:
21  Teensy 3.0 compatibility, Paul Stoffregen, paul@pjrc.com
22  Arduino Due compatibility, http://arduino.cc/forum/index.php?topic=141030
23  Fix DS18B20 example negative temperature
24  Fix DS18B20 example's low res modes, Ken Butcher
25  Improve reset timing, Mark Tillotson
26  Add const qualifiers, Bertrik Sikken
27  Add initial value input to crc16, Bertrik Sikken
28  Add target_search() function, Scott Roberts
29 
30 Version 2.1:
31  Arduino 1.0 compatibility, Paul Stoffregen
32  Improve temperature example, Paul Stoffregen
33  DS250x_PROM example, Guillermo Lovato
34  PIC32 (chipKit) compatibility, Jason Dangel, dangel.jason AT gmail.com
35  Improvements from Glenn Trewitt:
36  - crc16() now works
37  - check_crc16() does all of calculation/checking work.
38  - Added read_bytes() and write_bytes(), to reduce tedious loops.
39  - Added ds2408 example.
40  Delete very old, out-of-date readme file (info is here)
41 
42 Version 2.0: Modifications by Paul Stoffregen, January 2010:
43 http://www.pjrc.com/teensy/td_libs_OneWire.html
44  Search fix from Robin James
45  http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238032295/27#27
46  Use direct optimized I/O in all cases
47  Disable interrupts during timing critical sections
48  (this solves many random communication errors)
49  Disable interrupts during read-modify-write I/O
50  Reduce RAM consumption by eliminating unnecessary
51  variables and trimming many to 8 bits
52  Optimize both crc8 - table version moved to flash
53 
54 Modified to work with larger numbers of devices - avoids loop.
55 Tested in Arduino 11 alpha with 12 sensors.
56 26 Sept 2008 -- Robin James
57 http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238032295/27#27
58 
59 Updated to work with arduino-0008 and to include skip() as of
60 2007/07/06. --RJL20
61 
62 Modified to calculate the 8-bit CRC directly, avoiding the need for
63 the 256-byte lookup table to be loaded in RAM. Tested in arduino-0010
64 -- Tom Pollard, Jan 23, 2008
65 
66 Jim Studt's original library was modified by Josh Larios.
67 
68 Tom Pollard, pollard@alum.mit.edu, contributed around May 20, 2008
69 
70 Permission is hereby granted, free of charge, to any person obtaining
71 a copy of this software and associated documentation files (the
72 "Software"), to deal in the Software without restriction, including
73 without limitation the rights to use, copy, modify, merge, publish,
74 distribute, sublicense, and/or sell copies of the Software, and to
75 permit persons to whom the Software is furnished to do so, subject to
76 the following conditions:
77 
78 The above copyright notice and this permission notice shall be
79 included in all copies or substantial portions of the Software.
80 
81 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
82 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
83 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
84 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
85 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
86 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
87 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
88 
89 Much of the code was inspired by Derek Yerger's code, though I don't
90 think much of that remains. In any event that was..
91  (copyleft) 2006 by Derek Yerger - Free to distribute freely.
92 
93 The CRC code was excerpted and inspired by the Dallas Semiconductor
94 sample code bearing this copyright.
95 //---------------------------------------------------------------------------
96 // Copyright (C) 2000 Dallas Semiconductor Corporation, All Rights Reserved.
97 //
98 // Permission is hereby granted, free of charge, to any person obtaining a
99 // copy of this software and associated documentation files (the "Software"),
100 // to deal in the Software without restriction, including without limitation
101 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
102 // and/or sell copies of the Software, and to permit persons to whom the
103 // Software is furnished to do so, subject to the following conditions:
104 //
105 // The above copyright notice and this permission notice shall be included
106 // in all copies or substantial portions of the Software.
107 //
108 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
109 // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
110 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
111 // IN NO EVENT SHALL DALLAS SEMICONDUCTOR BE LIABLE FOR ANY CLAIM, DAMAGES
112 // OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
113 // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
114 // OTHER DEALINGS IN THE SOFTWARE.
115 //
116 // Except as contained in this notice, the name of Dallas Semiconductor
117 // shall not be used except as stated in the Dallas Semiconductor
118 // Branding Policy.
119 //--------------------------------------------------------------------------
120 */
121 
122 #include "OneWire.h"
123 
124 
125 OneWire::OneWire(uint8_t pin)
126 {
127  pinMode(pin, INPUT);
128  bitmask = PIN_TO_BITMASK(pin);
129  baseReg = PIN_TO_BASEREG(pin);
130 #if ONEWIRE_SEARCH
131  reset_search();
132 #endif
133 }
134 
135 
136 // Perform the onewire reset function. We will wait up to 250uS for
137 // the bus to come high, if it doesn't then it is broken or shorted
138 // and we return a 0;
139 //
140 // Returns 1 if a device asserted a presence pulse, 0 otherwise.
141 //
142 uint8_t OneWire::reset(void)
143 {
144  IO_REG_TYPE mask = bitmask;
145  volatile IO_REG_TYPE *reg IO_REG_ASM = baseReg;
146  uint8_t r;
147  uint8_t retries = 125;
148 
149  noInterrupts();
150  DIRECT_MODE_INPUT(reg, mask);
151  interrupts();
152  // wait until the wire is high... just in case
153  do {
154  if (--retries == 0) return 0;
155  delayMicroseconds(2);
156  } while ( !DIRECT_READ(reg, mask));
157 
158  noInterrupts();
159  DIRECT_WRITE_LOW(reg, mask);
160  DIRECT_MODE_OUTPUT(reg, mask); // drive output low
161  interrupts();
162  delayMicroseconds(480);
163  noInterrupts();
164  DIRECT_MODE_INPUT(reg, mask); // allow it to float
165  delayMicroseconds(70);
166  r = !DIRECT_READ(reg, mask);
167  interrupts();
168  delayMicroseconds(410);
169  return r;
170 }
171 
172 //
173 // Write a bit. Port and bit is used to cut lookup time and provide
174 // more certain timing.
175 //
176 void OneWire::write_bit(uint8_t v)
177 {
178  IO_REG_TYPE mask=bitmask;
179  volatile IO_REG_TYPE *reg IO_REG_ASM = baseReg;
180 
181  if (v & 1) {
182  noInterrupts();
183  DIRECT_WRITE_LOW(reg, mask);
184  DIRECT_MODE_OUTPUT(reg, mask); // drive output low
185  delayMicroseconds(10);
186  DIRECT_WRITE_HIGH(reg, mask); // drive output high
187  interrupts();
188  delayMicroseconds(55);
189  } else {
190  noInterrupts();
191  DIRECT_WRITE_LOW(reg, mask);
192  DIRECT_MODE_OUTPUT(reg, mask); // drive output low
193  delayMicroseconds(65);
194  DIRECT_WRITE_HIGH(reg, mask); // drive output high
195  interrupts();
196  delayMicroseconds(5);
197  }
198 }
199 
200 //
201 // Read a bit. Port and bit is used to cut lookup time and provide
202 // more certain timing.
203 //
204 uint8_t OneWire::read_bit(void)
205 {
206  IO_REG_TYPE mask=bitmask;
207  volatile IO_REG_TYPE *reg IO_REG_ASM = baseReg;
208  uint8_t r;
209 
210  noInterrupts();
211  DIRECT_MODE_OUTPUT(reg, mask);
212  DIRECT_WRITE_LOW(reg, mask);
213  delayMicroseconds(3);
214  DIRECT_MODE_INPUT(reg, mask); // let pin float, pull up will raise
215  delayMicroseconds(10);
216  r = DIRECT_READ(reg, mask);
217  interrupts();
218  delayMicroseconds(53);
219  return r;
220 }
221 
222 //
223 // Write a byte. The writing code uses the active drivers to raise the
224 // pin high, if you need power after the write (e.g. DS18S20 in
225 // parasite power mode) then set 'power' to 1, otherwise the pin will
226 // go tri-state at the end of the write to avoid heating in a short or
227 // other mishap.
228 //
229 void OneWire::write(uint8_t v, uint8_t power /* = 0 */) {
230  uint8_t bitMask;
231 
232  for (bitMask = 0x01; bitMask; bitMask <<= 1) {
233  OneWire::write_bit( (bitMask & v)?1:0);
234  }
235  if ( !power) {
236  noInterrupts();
237  DIRECT_MODE_INPUT(baseReg, bitmask);
238  DIRECT_WRITE_LOW(baseReg, bitmask);
239  interrupts();
240  }
241 }
242 
243 void OneWire::write_bytes(const uint8_t *buf, uint16_t count, bool power /* = 0 */) {
244  for (uint16_t i = 0 ; i < count ; i++)
245  write(buf[i]);
246  if (!power) {
247  noInterrupts();
248  DIRECT_MODE_INPUT(baseReg, bitmask);
249  DIRECT_WRITE_LOW(baseReg, bitmask);
250  interrupts();
251  }
252 }
253 
254 //
255 // Read a byte
256 //
257 uint8_t OneWire::read() {
258  uint8_t bitMask;
259  uint8_t r = 0;
260 
261  for (bitMask = 0x01; bitMask; bitMask <<= 1) {
262  if ( OneWire::read_bit()) r |= bitMask;
263  }
264  return r;
265 }
266 
267 void OneWire::read_bytes(uint8_t *buf, uint16_t count) {
268  for (uint16_t i = 0 ; i < count ; i++)
269  buf[i] = read();
270 }
271 
272 //
273 // Do a ROM select
274 //
275 void OneWire::select(const uint8_t rom[8])
276 {
277  uint8_t i;
278 
279  write(0x55); // Choose ROM
280 
281  for (i = 0; i < 8; i++) write(rom[i]);
282 }
283 
284 //
285 // Do a ROM skip
286 //
287 void OneWire::skip()
288 {
289  write(0xCC); // Skip ROM
290 }
291 
292 void OneWire::depower()
293 {
294  noInterrupts();
295  DIRECT_MODE_INPUT(baseReg, bitmask);
296  interrupts();
297 }
298 
299 #if ONEWIRE_SEARCH
300 
301 //
302 // You need to use this function to start a search again from the beginning.
303 // You do not need to do it for the first search, though you could.
304 //
305 void OneWire::reset_search()
306 {
307  // reset the search state
308  LastDiscrepancy = 0;
309  LastDeviceFlag = FALSE;
310  LastFamilyDiscrepancy = 0;
311  for(int i = 7; ; i--) {
312  ROM_NO[i] = 0;
313  if ( i == 0) break;
314  }
315 }
316 
317 // Setup the search to find the device type 'family_code' on the next call
318 // to search(*newAddr) if it is present.
319 //
320 void OneWire::target_search(uint8_t family_code)
321 {
322  // set the search state to find SearchFamily type devices
323  ROM_NO[0] = family_code;
324  for (uint8_t i = 1; i < 8; i++)
325  ROM_NO[i] = 0;
326  LastDiscrepancy = 64;
327  LastFamilyDiscrepancy = 0;
328  LastDeviceFlag = FALSE;
329 }
330 
331 //
332 // Perform a search. If this function returns a '1' then it has
333 // enumerated the next device and you may retrieve the ROM from the
334 // OneWire::address variable. If there are no devices, no further
335 // devices, or something horrible happens in the middle of the
336 // enumeration then a 0 is returned. If a new device is found then
337 // its address is copied to newAddr. Use OneWire::reset_search() to
338 // start over.
339 //
340 // --- Replaced by the one from the Dallas Semiconductor web site ---
341 //--------------------------------------------------------------------------
342 // Perform the 1-Wire Search Algorithm on the 1-Wire bus using the existing
343 // search state.
344 // Return TRUE : device found, ROM number in ROM_NO buffer
345 // FALSE : device not found, end of search
346 //
347 uint8_t OneWire::search(uint8_t *newAddr, bool search_mode /* = true */)
348 {
349  uint8_t id_bit_number;
350  uint8_t last_zero, rom_byte_number, search_result;
351  uint8_t id_bit, cmp_id_bit;
352 
353  unsigned char rom_byte_mask, search_direction;
354 
355  // initialize for search
356  id_bit_number = 1;
357  last_zero = 0;
358  rom_byte_number = 0;
359  rom_byte_mask = 1;
360  search_result = 0;
361 
362  // if the last call was not the last one
363  if (!LastDeviceFlag)
364  {
365  // 1-Wire reset
366  if (!reset())
367  {
368  // reset the search
369  LastDiscrepancy = 0;
370  LastDeviceFlag = FALSE;
371  LastFamilyDiscrepancy = 0;
372  return FALSE;
373  }
374 
375  // issue the search command
376  if (search_mode == true) {
377  write(0xF0); // NORMAL SEARCH
378  } else {
379  write(0xEC); // CONDITIONAL SEARCH
380  }
381 
382  // loop to do the search
383  do
384  {
385  // read a bit and its complement
386  id_bit = read_bit();
387  cmp_id_bit = read_bit();
388 
389  // check for no devices on 1-wire
390  if ((id_bit == 1) && (cmp_id_bit == 1))
391  break;
392  else
393  {
394  // all devices coupled have 0 or 1
395  if (id_bit != cmp_id_bit)
396  search_direction = id_bit; // bit write value for search
397  else
398  {
399  // if this discrepancy if before the Last Discrepancy
400  // on a previous next then pick the same as last time
401  if (id_bit_number < LastDiscrepancy)
402  search_direction = ((ROM_NO[rom_byte_number] & rom_byte_mask) > 0);
403  else
404  // if equal to last pick 1, if not then pick 0
405  search_direction = (id_bit_number == LastDiscrepancy);
406 
407  // if 0 was picked then record its position in LastZero
408  if (search_direction == 0)
409  {
410  last_zero = id_bit_number;
411 
412  // check for Last discrepancy in family
413  if (last_zero < 9)
414  LastFamilyDiscrepancy = last_zero;
415  }
416  }
417 
418  // set or clear the bit in the ROM byte rom_byte_number
419  // with mask rom_byte_mask
420  if (search_direction == 1)
421  ROM_NO[rom_byte_number] |= rom_byte_mask;
422  else
423  ROM_NO[rom_byte_number] &= ~rom_byte_mask;
424 
425  // serial number search direction write bit
426  write_bit(search_direction);
427 
428  // increment the byte counter id_bit_number
429  // and shift the mask rom_byte_mask
430  id_bit_number++;
431  rom_byte_mask <<= 1;
432 
433  // if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask
434  if (rom_byte_mask == 0)
435  {
436  rom_byte_number++;
437  rom_byte_mask = 1;
438  }
439  }
440  }
441  while(rom_byte_number < 8); // loop until through all ROM bytes 0-7
442 
443  // if the search was successful then
444  if (!(id_bit_number < 65))
445  {
446  // search successful so set LastDiscrepancy,LastDeviceFlag,search_result
447  LastDiscrepancy = last_zero;
448 
449  // check for last device
450  if (LastDiscrepancy == 0)
451  LastDeviceFlag = TRUE;
452 
453  search_result = TRUE;
454  }
455  }
456 
457  // if no device found then reset counters so next 'search' will be like a first
458  if (!search_result || !ROM_NO[0])
459  {
460  LastDiscrepancy = 0;
461  LastDeviceFlag = FALSE;
462  LastFamilyDiscrepancy = 0;
463  search_result = FALSE;
464  } else {
465  for (int i = 0; i < 8; i++) newAddr[i] = ROM_NO[i];
466  }
467  return search_result;
468  }
469 
470 #endif
471 
472 #if ONEWIRE_CRC
473 // The 1-Wire CRC scheme is described in Maxim Application Note 27:
474 // "Understanding and Using Cyclic Redundancy Checks with Maxim iButton Products"
475 //
476 
477 #if ONEWIRE_CRC8_TABLE
478 // This table comes from Dallas sample code where it is freely reusable,
479 // though Copyright (C) 2000 Dallas Semiconductor Corporation
480 static const uint8_t PROGMEM dscrc_table[] = {
481  0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65,
482  157,195, 33,127,252,162, 64, 30, 95, 1,227,189, 62, 96,130,220,
483  35,125,159,193, 66, 28,254,160,225,191, 93, 3,128,222, 60, 98,
484  190,224, 2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255,
485  70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89, 7,
486  219,133,103, 57,186,228, 6, 88, 25, 71,165,251,120, 38,196,154,
487  101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122, 36,
488  248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185,
489  140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205,
490  17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80,
491  175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238,
492  50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115,
493  202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139,
494  87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22,
495  233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168,
496  116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53};
497 
498 //
499 // Compute a Dallas Semiconductor 8 bit CRC. These show up in the ROM
500 // and the registers. (note: this might better be done without to
501 // table, it would probably be smaller and certainly fast enough
502 // compared to all those delayMicrosecond() calls. But I got
503 // confused, so I use this table from the examples.)
504 //
505 uint8_t OneWire::crc8(const uint8_t *addr, uint8_t len)
506 {
507  uint8_t crc = 0;
508 
509  while (len--) {
510  crc = pgm_read_byte(dscrc_table + (crc ^ *addr++));
511  }
512  return crc;
513 }
514 #else
515 //
516 // Compute a Dallas Semiconductor 8 bit CRC directly.
517 // this is much slower, but much smaller, than the lookup table.
518 //
519 uint8_t OneWire::crc8(const uint8_t *addr, uint8_t len)
520 {
521  uint8_t crc = 0;
522 
523  while (len--) {
524  uint8_t inbyte = *addr++;
525  for (uint8_t i = 8; i; i--) {
526  uint8_t mix = (crc ^ inbyte) & 0x01;
527  crc >>= 1;
528  if (mix) crc ^= 0x8C;
529  inbyte >>= 1;
530  }
531  }
532  return crc;
533 }
534 #endif
535 
536 #if ONEWIRE_CRC16
537 bool OneWire::check_crc16(const uint8_t* input, uint16_t len, const uint8_t* inverted_crc, uint16_t crc)
538 {
539  crc = ~crc16(input, len, crc);
540  return (crc & 0xFF) == inverted_crc[0] && (crc >> 8) == inverted_crc[1];
541 }
542 
543 uint16_t OneWire::crc16(const uint8_t* input, uint16_t len, uint16_t crc)
544 {
545  static const uint8_t oddparity[16] =
546  { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 };
547 
548  for (uint16_t i = 0 ; i < len ; i++) {
549  // Even though we're just copying a byte from the input,
550  // we'll be doing 16-bit computation with it.
551  uint16_t cdata = input[i];
552  cdata = (cdata ^ crc) & 0xff;
553  crc >>= 8;
554 
555  if (oddparity[cdata & 0x0F] ^ oddparity[cdata >> 4])
556  crc ^= 0xC001;
557 
558  cdata <<= 6;
559  crc ^= cdata;
560  cdata <<= 1;
561  crc ^= cdata;
562  }
563  return crc;
564 }
565 #endif
566 
567 #endif