Thu, 01 Nov 2018 16:54:03 +0100
Updated the README
0 | 1 | /* |
2 | * MIT License | |
3 | * | |
4 | * Copyright (c) 2017 David Antliff | |
5 | * Copyright (c) 2017 Chris Morgan <chmorgan@gmail.com> | |
6 | * | |
7 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
8 | * of this software and associated documentation files (the "Software"), to deal | |
9 | * in the Software without restriction, including without limitation the rights | |
10 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
11 | * copies of the Software, and to permit persons to whom the Software is | |
12 | * furnished to do so, subject to the following conditions: | |
13 | * | |
14 | * The above copyright notice and this permission notice shall be included in all | |
15 | * copies or substantial portions of the Software. | |
16 | * | |
17 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
18 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
19 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
20 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
21 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
22 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
23 | * SOFTWARE. | |
24 | */ | |
25 | ||
26 | /** | |
27 | * @file | |
28 | */ | |
29 | ||
30 | #include <stddef.h> | |
31 | #include <stdbool.h> | |
32 | #include <inttypes.h> | |
33 | #include <string.h> | |
34 | #include <stdlib.h> | |
35 | ||
36 | #include "freertos/FreeRTOS.h" | |
37 | #include "freertos/task.h" | |
38 | #include "esp_log.h" | |
39 | #include "sdkconfig.h" | |
40 | #include "driver/gpio.h" | |
41 | ||
42 | #include "owb.h" | |
43 | #include "owb_gpio.h" | |
44 | ||
45 | static const char * TAG = "owb"; | |
46 | ||
47 | static bool _is_init(const OneWireBus * bus) | |
48 | { | |
49 | bool ok = false; | |
50 | if (bus != NULL) | |
51 | { | |
52 | if (bus->driver) | |
53 | { | |
54 | // OK | |
55 | ok = true; | |
56 | } | |
57 | else | |
58 | { | |
59 | ESP_LOGE(TAG, "bus is not initialised"); | |
60 | } | |
61 | } | |
62 | else | |
63 | { | |
64 | ESP_LOGE(TAG, "bus is NULL"); | |
65 | } | |
66 | return ok; | |
67 | } | |
68 | ||
69 | /** | |
70 | * @brief 1-Wire 8-bit CRC lookup. | |
71 | * @param[in] crc Starting CRC value. Pass in prior CRC to accumulate. | |
72 | * @param[in] data Byte to feed into CRC. | |
73 | * @return Resultant CRC value. | |
74 | */ | |
75 | static uint8_t _calc_crc(uint8_t crc, uint8_t data) | |
76 | { | |
77 | // https://www.maximintegrated.com/en/app-notes/index.mvp/id/27 | |
78 | static const uint8_t table[256] = { | |
79 | 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65, | |
80 | 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220, | |
81 | 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98, | |
82 | 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255, | |
83 | 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7, | |
84 | 219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154, | |
85 | 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36, | |
86 | 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185, | |
87 | 140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205, | |
88 | 17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80, | |
89 | 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238, | |
90 | 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115, | |
91 | 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139, | |
92 | 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22, | |
93 | 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168, | |
94 | 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53 | |
95 | }; | |
96 | ||
97 | return table[crc ^ data]; | |
98 | } | |
99 | ||
100 | static uint8_t _calc_crc_block(uint8_t crc, const uint8_t * buffer, size_t len) | |
101 | { | |
102 | do | |
103 | { | |
104 | crc = _calc_crc(crc, *buffer++); | |
105 | ESP_LOGD(TAG, "crc 0x%02x, len %d", (int)crc, (int)len); | |
106 | } | |
107 | while (--len > 0); | |
108 | return crc; | |
109 | } | |
110 | ||
111 | /** | |
112 | * @param[out] is_found true if a device was found, false if not | |
113 | * @return status | |
114 | */ | |
115 | static owb_status _search(const OneWireBus * bus, OneWireBus_SearchState * state, bool *is_found) | |
116 | { | |
117 | // Based on https://www.maximintegrated.com/en/app-notes/index.mvp/id/187 | |
118 | ||
119 | // initialize for search | |
120 | int id_bit_number = 1; | |
121 | int last_zero = 0; | |
122 | int rom_byte_number = 0; | |
123 | uint8_t id_bit = 0; | |
124 | uint8_t cmp_id_bit = 0; | |
125 | uint8_t rom_byte_mask = 1; | |
126 | uint8_t search_direction = 0; | |
127 | bool search_result = false; | |
128 | uint8_t crc8 = 0; | |
129 | owb_status status; | |
130 | ||
131 | // if the last call was not the last one | |
132 | if (!state->last_device_flag) | |
133 | { | |
134 | // 1-Wire reset | |
135 | bool is_present; | |
136 | bus->driver->reset(bus, &is_present); | |
137 | if (!is_present) | |
138 | { | |
139 | // reset the search | |
140 | state->last_discrepancy = 0; | |
141 | state->last_device_flag = false; | |
142 | state->last_family_discrepancy = 0; | |
143 | *is_found = false; | |
144 | return OWB_STATUS_OK; | |
145 | } | |
146 | ||
147 | // issue the search command | |
148 | bus->driver->write_bits(bus, OWB_ROM_SEARCH, 8); | |
149 | ||
150 | // loop to do the search | |
151 | do | |
152 | { | |
153 | id_bit = cmp_id_bit = 0; | |
154 | ||
155 | // read a bit and its complement | |
156 | bus->driver->read_bits(bus, &id_bit, 1); | |
157 | bus->driver->read_bits(bus, &cmp_id_bit, 1); | |
158 | ||
159 | // check for no devices on 1-wire (signal level is high in both bit reads) | |
160 | if (id_bit && cmp_id_bit) | |
161 | { | |
162 | break; | |
163 | } else | |
164 | { | |
165 | // all devices coupled have 0 or 1 | |
166 | if (id_bit != cmp_id_bit) | |
167 | { | |
168 | search_direction = (id_bit) ? 1 : 0; // bit write value for search | |
169 | } else | |
170 | { | |
171 | // if this discrepancy if before the Last Discrepancy | |
172 | // on a previous next then pick the same as last time | |
173 | if (id_bit_number < state->last_discrepancy) | |
174 | search_direction = ((state->rom_code.bytes[rom_byte_number] & rom_byte_mask) > 0); | |
175 | else | |
176 | // if equal to last pick 1, if not then pick 0 | |
177 | search_direction = (id_bit_number == state->last_discrepancy); | |
178 | ||
179 | // if 0 was picked then record its position in LastZero | |
180 | if (search_direction == 0) | |
181 | { | |
182 | last_zero = id_bit_number; | |
183 | ||
184 | // check for Last discrepancy in family | |
185 | if (last_zero < 9) | |
186 | state->last_family_discrepancy = last_zero; | |
187 | } | |
188 | } | |
189 | ||
190 | // set or clear the bit in the ROM byte rom_byte_number | |
191 | // with mask rom_byte_mask | |
192 | if (search_direction == 1) | |
193 | state->rom_code.bytes[rom_byte_number] |= rom_byte_mask; | |
194 | else | |
195 | state->rom_code.bytes[rom_byte_number] &= ~rom_byte_mask; | |
196 | ||
197 | // serial number search direction write bit | |
198 | bus->driver->write_bits(bus, search_direction, 1); | |
199 | ||
200 | // increment the byte counter id_bit_number | |
201 | // and shift the mask rom_byte_mask | |
202 | id_bit_number++; | |
203 | rom_byte_mask <<= 1; | |
204 | ||
205 | // if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask | |
206 | if (rom_byte_mask == 0) | |
207 | { | |
208 | crc8 = owb_crc8_byte(crc8, state->rom_code.bytes[rom_byte_number]); // accumulate the CRC | |
209 | rom_byte_number++; | |
210 | rom_byte_mask = 1; | |
211 | } | |
212 | } | |
213 | } | |
214 | while(rom_byte_number < 8); // loop until through all ROM bytes 0-7 | |
215 | ||
216 | // if the search was successful then | |
217 | if (!((id_bit_number < 65) || (crc8 != 0))) | |
218 | { | |
219 | // search successful so set LastDiscrepancy,LastDeviceFlag,search_result | |
220 | state->last_discrepancy = last_zero; | |
221 | ||
222 | // check for last device | |
223 | if (state->last_discrepancy == 0) | |
224 | state->last_device_flag = true; | |
225 | ||
226 | search_result = true; | |
227 | } | |
228 | } | |
229 | ||
230 | // if no device found then reset counters so next 'search' will be like a first | |
231 | if (!search_result || !state->rom_code.bytes[0]) | |
232 | { | |
233 | state->last_discrepancy = 0; | |
234 | state->last_device_flag = false; | |
235 | state->last_family_discrepancy = 0; | |
236 | search_result = false; | |
237 | } | |
238 | ||
239 | status = OWB_STATUS_OK; | |
240 | ||
241 | *is_found = search_result; | |
242 | ||
243 | return status; | |
244 | } | |
245 | ||
246 | // Public API | |
247 | ||
248 | owb_status owb_uninitialize(OneWireBus * bus) | |
249 | { | |
250 | owb_status status; | |
251 | ||
252 | if(!_is_init(bus)) | |
253 | { | |
254 | status = OWB_STATUS_NOT_INITIALIZED; | |
255 | } else | |
256 | { | |
257 | bus->driver->uninitialize(bus); | |
258 | status = OWB_STATUS_OK; | |
259 | } | |
260 | ||
261 | return status; | |
262 | } | |
263 | ||
264 | owb_status owb_use_crc(OneWireBus * bus, bool use_crc) | |
265 | { | |
266 | owb_status status; | |
267 | ||
268 | if(!bus) | |
269 | { | |
270 | status = OWB_STATUS_PARAMETER_NULL; | |
271 | } else if (!_is_init(bus)) | |
272 | { | |
273 | status = OWB_STATUS_NOT_INITIALIZED; | |
274 | } else | |
275 | { | |
276 | bus->use_crc = use_crc; | |
277 | ESP_LOGD(TAG, "use_crc %d", bus->use_crc); | |
278 | ||
279 | status = OWB_STATUS_OK; | |
280 | } | |
281 | ||
282 | return status; | |
283 | } | |
284 | ||
285 | owb_status owb_read_rom(const OneWireBus * bus, OneWireBus_ROMCode *rom_code) | |
286 | { | |
287 | owb_status status; | |
288 | ||
289 | memset(rom_code, 0, sizeof(OneWireBus_ROMCode)); | |
290 | ||
291 | if(!bus || !rom_code) | |
292 | { | |
293 | status = OWB_STATUS_PARAMETER_NULL; | |
294 | } else if (!_is_init(bus)) | |
295 | { | |
296 | status = OWB_STATUS_NOT_INITIALIZED; | |
297 | } else | |
298 | { | |
299 | bool is_present; | |
300 | bus->driver->reset(bus, &is_present); | |
301 | if (is_present) | |
302 | { | |
303 | uint8_t value = OWB_ROM_READ; | |
304 | bus->driver->write_bits(bus, value, 8); | |
305 | owb_read_bytes(bus, rom_code->bytes, sizeof(OneWireBus_ROMCode)); | |
306 | ||
307 | if (bus->use_crc) | |
308 | { | |
309 | if (owb_crc8_bytes(0, rom_code->bytes, sizeof(OneWireBus_ROMCode)) != 0) | |
310 | { | |
311 | ESP_LOGE(TAG, "CRC failed"); | |
312 | memset(rom_code->bytes, 0, sizeof(OneWireBus_ROMCode)); | |
313 | status = OWB_STATUS_CRC_FAILED; | |
314 | } else | |
315 | { | |
316 | status = OWB_STATUS_OK; | |
317 | } | |
318 | } else | |
319 | { | |
320 | status = OWB_STATUS_OK; | |
321 | } | |
322 | char rom_code_s[OWB_ROM_CODE_STRING_LENGTH]; | |
323 | owb_string_from_rom_code(*rom_code, rom_code_s, sizeof(rom_code_s)); | |
324 | ESP_LOGD(TAG, "rom_code %s", rom_code_s); | |
325 | } | |
326 | else | |
327 | { | |
328 | status = OWB_STATUS_DEVICE_NOT_RESPONDING; | |
329 | ESP_LOGE(TAG, "ds18b20 device not responding"); | |
330 | } | |
331 | } | |
332 | ||
333 | return status; | |
334 | } | |
335 | ||
336 | owb_status owb_verify_rom(const OneWireBus * bus, OneWireBus_ROMCode rom_code, bool* is_present) | |
337 | { | |
338 | owb_status status; | |
339 | bool result = false; | |
340 | ||
341 | if (!bus || !is_present) | |
342 | { | |
343 | status = OWB_STATUS_PARAMETER_NULL; | |
344 | } | |
345 | else if (!_is_init(bus)) | |
346 | { | |
347 | status = OWB_STATUS_NOT_INITIALIZED; | |
348 | } | |
349 | else | |
350 | { | |
351 | OneWireBus_SearchState state = { | |
352 | .last_discrepancy = 64, | |
353 | .last_device_flag = false, | |
354 | }; | |
355 | ||
356 | bool is_found = false; | |
357 | while (!state.last_device_flag && !is_found) | |
358 | { | |
359 | _search(bus, &state, &is_found); | |
360 | if (is_found) | |
361 | { | |
362 | result = true; | |
363 | for (int i = 0; i < sizeof(state.rom_code.bytes) && result; ++i) | |
364 | { | |
365 | result = rom_code.bytes[i] == state.rom_code.bytes[i]; | |
366 | ESP_LOGD(TAG, "%02x %02x", rom_code.bytes[i], state.rom_code.bytes[i]); | |
367 | } | |
368 | is_found = result; | |
369 | } | |
370 | } | |
371 | ||
372 | ESP_LOGD(TAG, "rom code %sfound", result ? "" : "not "); | |
373 | *is_present = result; | |
374 | status = OWB_STATUS_OK; | |
375 | } | |
376 | ||
377 | return status; | |
378 | } | |
379 | ||
380 | owb_status owb_reset(const OneWireBus * bus, bool* a_device_present) | |
381 | { | |
382 | owb_status status; | |
383 | ||
384 | if(!bus || !a_device_present) | |
385 | { | |
386 | status = OWB_STATUS_PARAMETER_NULL; | |
387 | } else if(!_is_init(bus)) | |
388 | { | |
389 | status = OWB_STATUS_NOT_INITIALIZED; | |
390 | } else | |
391 | { | |
392 | bus->driver->reset(bus, a_device_present); | |
393 | status = OWB_STATUS_OK; | |
394 | } | |
395 | ||
396 | return status; | |
397 | } | |
398 | ||
399 | owb_status owb_write_byte(const OneWireBus * bus, uint8_t data) | |
400 | { | |
401 | owb_status status; | |
402 | ||
403 | if(!bus) | |
404 | { | |
405 | status = OWB_STATUS_PARAMETER_NULL; | |
406 | } else if (!_is_init(bus)) | |
407 | { | |
408 | status = OWB_STATUS_NOT_INITIALIZED; | |
409 | } else | |
410 | { | |
411 | bus->driver->write_bits(bus, data, 8); | |
412 | status = OWB_STATUS_OK; | |
413 | } | |
414 | ||
415 | return status; | |
416 | } | |
417 | ||
418 | owb_status owb_read_byte(const OneWireBus * bus, uint8_t *out) | |
419 | { | |
420 | owb_status status; | |
421 | ||
422 | if(!bus || !out) | |
423 | { | |
424 | status = OWB_STATUS_PARAMETER_NULL; | |
425 | } else if (!_is_init(bus)) | |
426 | { | |
427 | status = OWB_STATUS_NOT_INITIALIZED; | |
428 | } else | |
429 | { | |
430 | bus->driver->read_bits(bus, out, 8); | |
431 | status = OWB_STATUS_OK; | |
432 | } | |
433 | ||
434 | return status; | |
435 | } | |
436 | ||
437 | owb_status owb_read_bytes(const OneWireBus * bus, uint8_t * buffer, unsigned int len) | |
438 | { | |
439 | owb_status status; | |
440 | ||
441 | if(!bus || !buffer) | |
442 | { | |
443 | status = OWB_STATUS_PARAMETER_NULL; | |
444 | } else if (!_is_init(bus)) | |
445 | { | |
446 | status = OWB_STATUS_NOT_INITIALIZED; | |
447 | } else | |
448 | { | |
449 | for (int i = 0; i < len; ++i) | |
450 | { | |
451 | uint8_t out; | |
452 | bus->driver->read_bits(bus, &out, 8); | |
453 | buffer[i] = out; | |
454 | } | |
455 | ||
456 | status = OWB_STATUS_OK; | |
457 | } | |
458 | ||
459 | return status; | |
460 | } | |
461 | ||
462 | owb_status owb_write_bytes(const OneWireBus * bus, const uint8_t * buffer, unsigned int len) | |
463 | { | |
464 | owb_status status; | |
465 | ||
466 | if(!bus || !buffer) | |
467 | { | |
468 | status = OWB_STATUS_PARAMETER_NULL; | |
469 | } else if (!_is_init(bus)) | |
470 | { | |
471 | status = OWB_STATUS_NOT_INITIALIZED; | |
472 | } else | |
473 | { | |
474 | for (int i = 0; i < len; i++) | |
475 | { | |
476 | bus->driver->write_bits(bus, buffer[i], 8); | |
477 | } | |
478 | ||
479 | status = OWB_STATUS_OK; | |
480 | } | |
481 | ||
482 | return status; | |
483 | } | |
484 | ||
485 | owb_status owb_write_rom_code(const OneWireBus * bus, OneWireBus_ROMCode rom_code) | |
486 | { | |
487 | owb_status status; | |
488 | ||
489 | if(!bus) | |
490 | { | |
491 | status = OWB_STATUS_PARAMETER_NULL; | |
492 | } else if (!_is_init(bus)) | |
493 | { | |
494 | status = OWB_STATUS_NOT_INITIALIZED; | |
495 | } else | |
496 | { | |
497 | owb_write_bytes(bus, (uint8_t*)&rom_code, sizeof(rom_code)); | |
498 | status = OWB_STATUS_OK; | |
499 | } | |
500 | ||
501 | return status; | |
502 | } | |
503 | ||
504 | uint8_t owb_crc8_byte(uint8_t crc, uint8_t data) | |
505 | { | |
506 | return _calc_crc(crc, data); | |
507 | } | |
508 | ||
509 | uint8_t owb_crc8_bytes(uint8_t crc, const uint8_t * data, size_t len) | |
510 | { | |
511 | return _calc_crc_block(crc, data, len); | |
512 | } | |
513 | ||
514 | owb_status owb_search_first(const OneWireBus * bus, OneWireBus_SearchState * state, bool* found_device) | |
515 | { | |
516 | bool result; | |
517 | owb_status status; | |
518 | ||
519 | if(!bus || !state || !found_device) | |
520 | { | |
521 | status = OWB_STATUS_PARAMETER_NULL; | |
522 | } else if (!_is_init(bus)) | |
523 | { | |
524 | status = OWB_STATUS_NOT_INITIALIZED; | |
525 | } else | |
526 | { | |
527 | memset(&state->rom_code, 0, sizeof(state->rom_code)); | |
528 | state->last_discrepancy = 0; | |
529 | state->last_family_discrepancy = 0; | |
530 | state->last_device_flag = false; | |
531 | _search(bus, state, &result); | |
532 | status = OWB_STATUS_OK; | |
533 | ||
534 | *found_device = result; | |
535 | } | |
536 | ||
537 | return status; | |
538 | } | |
539 | ||
540 | owb_status owb_search_next(const OneWireBus * bus, OneWireBus_SearchState * state, bool* found_device) | |
541 | { | |
542 | owb_status status; | |
543 | bool result = false; | |
544 | ||
545 | if(!bus || !state || !found_device) | |
546 | { | |
547 | status = OWB_STATUS_PARAMETER_NULL; | |
548 | } else if (!_is_init(bus)) | |
549 | { | |
550 | status = OWB_STATUS_NOT_INITIALIZED; | |
551 | } else | |
552 | { | |
553 | _search(bus, state, &result); | |
554 | status = OWB_STATUS_OK; | |
555 | ||
556 | *found_device = result; | |
557 | } | |
558 | ||
559 | return status; | |
560 | } | |
561 | ||
562 | char * owb_string_from_rom_code(OneWireBus_ROMCode rom_code, char * buffer, size_t len) | |
563 | { | |
564 | for (int i = sizeof(rom_code.bytes) - 1; i >= 0; i--) | |
565 | { | |
566 | sprintf(buffer, "%02x", rom_code.bytes[i]); | |
567 | buffer += 2; | |
568 | } | |
569 | return buffer; | |
570 | } |