Mercurial > ~darius > hgwebdir.cgi > avr-lib
annotate 1wire.c @ 13:6f8f7b87d2f1
- Rename 1wire config example to note it's for AVR.
- Add STM32 config.
- Rework a little to remove AVR depedencies.
- Re-do OWProgROM in the no VPP case so it doesn't generate warnings.
| author | Daniel O'Connor <darius@dons.net.au> |
|---|---|
| date | Tue, 07 Feb 2012 13:53:21 +1030 |
| parents | 3879f487b661 |
| children | d8002c716678 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 * Various 1 wire routines | |
| 3 * Search routine is copied from the Dallas owpd library with mods | |
| 4 * available from here http://www.ibutton.com/software/1wire/wirekit.html | |
| 5 * | |
| 6 * $Id$ | |
| 7 * | |
| 8 * Copyright (c) 2004 | |
| 9 * Daniel O'Connor <darius@dons.net.au>. All rights reserved. | |
| 10 * | |
| 11 * Redistribution and use in source and binary forms, with or without | |
| 12 * modification, are permitted provided that the following conditions | |
| 13 * are met: | |
| 14 * 1. Redistributions of source code must retain the above copyright | |
| 15 * notice, this list of conditions and the following disclaimer. | |
| 16 * 2. Redistributions in binary form must reproduce the above copyright | |
| 17 * notice, this list of conditions and the following disclaimer in the | |
| 18 * documentation and/or other materials provided with the distribution. | |
| 19 * | |
| 20 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |
| 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 23 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE | |
| 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 30 * SUCH DAMAGE. | |
| 31 */ | |
| 32 | |
| 33 /* | |
| 34 * No user servicable parts inside | |
| 35 * | |
| 36 * Modify 1wire-config.h | |
| 37 */ | |
| 38 | |
| 39 #include <stdio.h> | |
|
13
6f8f7b87d2f1
- Rename 1wire config example to note it's for AVR.
Daniel O'Connor <darius@dons.net.au>
parents:
0
diff
changeset
|
40 #include <stdint.h> |
|
6f8f7b87d2f1
- Rename 1wire config example to note it's for AVR.
Daniel O'Connor <darius@dons.net.au>
parents:
0
diff
changeset
|
41 #include "1wire-config.h" |
| 0 | 42 #include "1wire.h" |
| 43 | |
| 44 static uint8_t OW_LastDevice = 0; | |
| 45 static uint8_t OW_LastDiscrepancy = 0; | |
| 46 static uint8_t OW_LastFamilyDiscrepancy = 0; | |
| 47 | |
| 48 const PROGMEM char *OWProgROM_Status[] = { | |
| 49 "OK", | |
| 50 "no HW support", | |
| 51 "Invalid params", | |
| 52 "module missing/broken" | |
| 53 }; | |
| 54 | |
| 55 /*----------------------------------------------------------------------------- | |
| 56 * Configure the IO port as we need | |
| 57 */ | |
| 58 void | |
| 59 OWInit(void) { | |
| 60 OWBUSINIT(); | |
| 61 OWSETBUSHIGH(); | |
| 62 } | |
| 63 | |
| 64 /*----------------------------------------------------------------------------- | |
| 65 * Generate a 1-Wire reset, return 0 if presence pulse was found, 1 if it | |
| 66 * wasn't, or 2 if the line appears to be being held low. | |
| 67 * | |
| 68 * (NOTE: Does not handle alarm presence from DS2404/DS1994) | |
| 69 */ | |
| 70 uint8_t | |
| 71 OWTouchReset(void) { | |
| 72 OWDELAY_G; | |
| 73 | |
| 74 /* Check the bus isn't being held low (ie it's broken) Do it after | |
| 75 * the delay so we guarantee we don't see a slave from a previous | |
| 76 * comms attempt | |
| 77 */ | |
| 78 OWSETREAD(); | |
| 79 if(OWREADBUS() == 0) | |
| 80 return 2; | |
| 81 | |
| 82 OWSETBUSLOW(); | |
| 83 OWDELAY_H; | |
| 84 OWSETBUSHIGH(); | |
| 85 OWDELAY_I; | |
| 86 | |
| 87 OWSETREAD(); | |
| 88 return(OWREADBUS()); | |
| 89 } | |
| 90 | |
| 91 /*----------------------------------------------------------------------------- | |
| 92 * Send a 1-wire write bit. | |
| 93 */ | |
| 94 void | |
| 95 OWWriteBit(uint8_t bit) { | |
| 96 OWDELAY_I; | |
| 97 | |
| 98 if (bit) { | |
| 99 OWSETBUSLOW(); | |
| 100 OWDELAY_A; | |
| 101 OWSETBUSHIGH(); | |
| 102 OWDELAY_B; | |
| 103 } else { | |
| 104 OWSETBUSLOW(); | |
| 105 OWDELAY_C; | |
| 106 OWSETBUSHIGH(); | |
| 107 OWDELAY_D; | |
| 108 } | |
| 109 } | |
| 110 | |
| 111 /*----------------------------------------------------------------------------- | |
| 112 * Read a bit from the 1-wire bus and return it. | |
| 113 */ | |
| 114 uint8_t | |
| 115 OWReadBit(void) { | |
| 116 OWDELAY_I; | |
| 117 | |
| 118 OWSETBUSLOW(); | |
| 119 OWDELAY_A; | |
| 120 OWSETBUSHIGH(); | |
| 121 OWDELAY_E; | |
| 122 OWSETREAD(); | |
| 123 return(OWREADBUS()); | |
| 124 } | |
| 125 | |
| 126 /*----------------------------------------------------------------------------- | |
| 127 * Write a byte to the 1-wire bus | |
| 128 */ | |
| 129 void | |
| 130 OWWriteByte(uint8_t data) { | |
| 131 uint8_t i; | |
| 132 | |
| 133 /* Send LSB first */ | |
| 134 for (i = 0; i < 8; i++) { | |
| 135 OWWriteBit(data & 0x01); | |
| 136 data >>= 1; | |
| 137 } | |
| 138 } | |
| 139 | |
| 140 /*----------------------------------------------------------------------------- | |
| 141 * Read a byte from the 1-wire bus | |
| 142 */ | |
| 143 uint8_t | |
| 144 OWReadByte(void) { | |
| 145 int i, result = 0; | |
| 146 | |
| 147 for (i = 0; i < 8; i++) { | |
| 148 result >>= 1; | |
| 149 if (OWReadBit()) | |
| 150 result |= 0x80; | |
| 151 } | |
| 152 return(result); | |
| 153 } | |
| 154 | |
| 155 /*----------------------------------------------------------------------------- | |
| 156 * Write a 1-wire data byte and return the sampled result. | |
| 157 */ | |
| 158 uint8_t | |
| 159 OWTouchByte(uint8_t data) { | |
| 160 uint8_t i, result = 0; | |
| 161 | |
| 162 for (i = 0; i < 8; i++) { | |
| 163 result >>= 1; | |
| 164 | |
| 165 /* If sending a 1 then read a bit, otherwise write a 0 */ | |
| 166 if (data & 0x01) { | |
| 167 if (OWReadBit()) | |
| 168 result |= 0x80; | |
| 169 } else | |
| 170 OWWriteBit(0); | |
| 171 | |
| 172 data >>= 1; | |
| 173 } | |
| 174 | |
| 175 return(result); | |
| 176 } | |
| 177 | |
| 178 /*----------------------------------------------------------------------------- | |
| 179 * Write a block of bytes to the 1-wire bus and return the sampled result in | |
| 180 * the same buffer | |
| 181 */ | |
| 182 void | |
| 183 OWBlock(uint8_t *data, int len) { | |
| 184 int i; | |
| 185 | |
| 186 for (i = 0; i < len; i++) | |
| 187 data[i] = OWTouchByte(data[i]); | |
| 188 } | |
| 189 | |
| 190 | |
| 191 /*----------------------------------------------------------------------------- | |
| 192 * Send a 1 wire command to a device, or all if no ROM ID provided | |
| 193 */ | |
| 194 void | |
| 195 OWSendCmd(uint8_t *ROM, uint8_t cmd) { | |
| 196 uint8_t i; | |
| 197 | |
| 198 OWTouchReset(); | |
| 199 | |
| 200 if (ROM == NULL) | |
| 201 OWWriteByte(OW_SKIP_ROM_CMD); | |
| 202 else { | |
| 203 OWWriteByte(OW_MATCH_ROM_CMD); | |
| 204 for (i = 0; i < 8; i++) | |
| 205 OWWriteByte(ROM[i]); | |
| 206 } | |
| 207 OWWriteByte(cmd); | |
| 208 } | |
| 209 | |
| 210 /*----------------------------------------------------------------------------- | |
| 211 * Search algorithm from App note 187 (and 162) | |
| 212 * | |
| 213 * OWFirst/OWNext return.. | |
| 214 * 1 when something is found, | |
| 215 * 0 no more modules | |
| 216 * -1 if no presence pulse, | |
| 217 * -2 if bad CRC, | |
| 218 * -3 if bad wiring. | |
| 219 */ | |
| 220 uint8_t | |
| 221 OWFirst(uint8_t *ROM, uint8_t do_reset, uint8_t alarm_only) { | |
| 222 /* Reset state */ | |
| 223 OW_LastDiscrepancy = 0; | |
| 224 OW_LastDevice = 0; | |
| 225 OW_LastFamilyDiscrepancy = 0; | |
| 226 | |
| 227 /* Go looking */ | |
| 228 return (OWNext(ROM, do_reset, alarm_only)); | |
| 229 } | |
| 230 | |
| 231 /* Returns 1 when something is found, 0 if nothing left */ | |
| 232 uint8_t | |
| 233 OWNext(uint8_t *ROM, uint8_t do_reset, uint8_t alarm_only) { | |
| 234 uint8_t bit_test, search_direction, bit_number; | |
| 235 uint8_t last_zero, rom_byte_number, rom_byte_mask; | |
| 236 uint8_t lastcrc8, crcaccum; | |
| 237 int8_t next_result; | |
| 238 | |
| 239 /* Init for search */ | |
| 240 bit_number = 1; | |
| 241 last_zero = 0; | |
| 242 rom_byte_number = 0; | |
| 243 rom_byte_mask = 1; | |
| 244 next_result = OW_NOMODULES; | |
| 245 lastcrc8 = 0; | |
| 246 crcaccum = 0; | |
| 247 | |
| 248 /* if the last call was not the last one */ | |
| 249 if (!OW_LastDevice) { | |
| 250 /* check if reset first is requested */ | |
| 251 if (do_reset) { | |
| 252 /* reset the 1-wire | |
| 253 * if there are no parts on 1-wire, return 0 */ | |
| 254 OWPUTSP(PSTR("Resetting\r\n")); | |
| 255 switch (OWTouchReset()) { | |
| 256 case 0: | |
| 257 break; | |
| 258 | |
| 259 case 1: | |
| 260 /* reset the search */ | |
| 261 OW_LastDiscrepancy = 0; | |
| 262 OW_LastFamilyDiscrepancy = 0; | |
| 263 OWPUTSP(PSTR("No devices on bus\r\n")); | |
| 264 return OW_NOPRESENCE; | |
| 265 break; | |
| 266 | |
| 267 case 2: | |
| 268 /* reset the search */ | |
| 269 OW_LastDiscrepancy = 0; | |
| 270 OW_LastFamilyDiscrepancy = 0; | |
| 271 OWPUTSP(PSTR("Bus appears to be being held low\r\n")); | |
| 272 return OW_BADWIRE; | |
| 273 break; | |
| 274 | |
| 275 } | |
| 276 } | |
| 277 | |
| 278 /* If finding alarming devices issue a different command */ | |
| 279 if (alarm_only) | |
| 280 OWWriteByte(OW_SEARCH_ALRM_CMD); /* issue the alarming search command */ | |
| 281 else | |
| 282 OWWriteByte(OW_SEARCH_ROM_CMD); /* issue the search command */ | |
| 283 | |
| 284 /* pause before beginning the search */ | |
| 285 OWDELAY_I; | |
| 286 OWDELAY_I; | |
| 287 OWDELAY_I; | |
| 288 | |
| 289 /* loop to do the search */ | |
| 290 do { | |
| 291 /* read a bit and its compliment */ | |
| 292 bit_test = OWReadBit() << 1; | |
| 293 bit_test |= OWReadBit(); | |
| 294 | |
| 295 OWPRINTFP(PSTR("bit_test = %d\r\n"), bit_test); | |
| 296 | |
| 297 /* check for no devices on 1-wire */ | |
| 298 if (bit_test == 3) { | |
| 299 OWPRINTFP(PSTR("bit_test = %d\r\n"), bit_test); | |
| 300 return(OW_BADWIRE); | |
| 301 } | |
| 302 else { | |
| 303 /* all devices coupled have 0 or 1 */ | |
| 304 if (bit_test > 0) | |
| 305 search_direction = !(bit_test & 0x01); /* bit write value for search */ | |
| 306 else { | |
| 307 /* if this discrepancy is before the Last Discrepancy | |
| 308 * on a previous OWNext then pick the same as last time */ | |
| 309 if (bit_number < OW_LastDiscrepancy) | |
| 310 search_direction = ((ROM[rom_byte_number] & rom_byte_mask) > 0); | |
| 311 else | |
| 312 /* if equal to last pick 1, if not then pick 0 */ | |
| 313 search_direction = (bit_number == OW_LastDiscrepancy); | |
| 314 | |
| 315 /* if 0 was picked then record its position in LastZero */ | |
| 316 if (search_direction == 0) { | |
| 317 last_zero = bit_number; | |
| 318 | |
| 319 /* check for Last discrepancy in family */ | |
| 320 if (last_zero < 9) | |
| 321 OW_LastFamilyDiscrepancy = last_zero; | |
| 322 } | |
| 323 } | |
| 324 | |
| 325 /* set or clear the bit in the ROM byte rom_byte_number | |
| 326 * with mask rom_byte_mask */ | |
| 327 if (search_direction == 1) | |
| 328 ROM[rom_byte_number] |= rom_byte_mask; | |
| 329 else | |
| 330 ROM[rom_byte_number] &= ~rom_byte_mask; | |
| 331 | |
| 332 /* serial number search direction write bit */ | |
| 333 OWWriteBit(search_direction); | |
| 334 | |
| 335 /* increment the byte counter bit_number | |
| 336 * and shift the mask rom_byte_mask */ | |
| 337 bit_number++; | |
| 338 rom_byte_mask <<= 1; | |
| 339 | |
| 340 /* if the mask is 0 then go to new ROM byte rom_byte_number | |
| 341 * and reset mask */ | |
| 342 if (rom_byte_mask == 0) { | |
| 343 OWCRC(ROM[rom_byte_number], &crcaccum); /* accumulate the CRC */ | |
| 344 lastcrc8 = crcaccum; | |
| 345 | |
| 346 rom_byte_number++; | |
| 347 rom_byte_mask = 1; | |
| 348 } | |
| 349 } | |
| 350 } while (rom_byte_number < 8); /* loop until through all ROM bytes 0-7 */ | |
| 351 | |
| 352 /* if the search was successful then */ | |
| 353 if (!(bit_number < 65) || lastcrc8) { | |
| 354 if (lastcrc8) { | |
| 355 OWPRINTFP(PSTR("Bad CRC (%d)\r\n"), lastcrc8); | |
| 356 next_result = OW_BADCRC; | |
| 357 } else { | |
| 358 /* search successful so set LastDiscrepancy,LastDevice,next_result */ | |
| 359 OW_LastDiscrepancy = last_zero; | |
| 360 OW_LastDevice = (OW_LastDiscrepancy == 0); | |
| 361 OWPRINTFP(PSTR("Last device = %d\r\n"), OW_LastDevice); | |
| 362 next_result = OW_FOUND; | |
| 363 } | |
| 364 } | |
| 365 } | |
| 366 | |
| 367 /* if no device found then reset counters so next 'next' will be | |
| 368 * like a first */ | |
| 369 if (next_result != OW_FOUND || ROM[0] == 0) { | |
| 370 OW_LastDiscrepancy = 0; | |
| 371 OW_LastDevice = 0; | |
| 372 OW_LastFamilyDiscrepancy = 0; | |
| 373 } | |
| 374 | |
| 375 if (next_result == OW_FOUND && ROM[0] == 0x00) | |
| 376 next_result = OW_BADWIRE; | |
| 377 | |
| 378 return next_result; | |
| 379 | |
| 380 } | |
| 381 | |
| 382 uint8_t PROGMEM dscrc_table[] = { | |
| 383 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65, | |
| 384 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220, | |
| 385 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98, | |
| 386 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255, | |
| 387 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7, | |
| 388 219, 133,103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154, | |
| 389 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36, | |
| 390 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185, | |
| 391 140,210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113,147, 205, | |
| 392 17, 79, 173, 243, 112, 46, 204, 146, 211,141, 111, 49, 178, 236, 14, 80, | |
| 393 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82,176, 238, | |
| 394 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115, | |
| 395 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139, | |
| 396 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22, | |
| 397 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168, | |
| 398 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53 | |
| 399 }; | |
| 400 | |
| 401 /*----------------------------------------------------------------------------- | |
| 402 * Update *crc based on the value of x | |
| 403 */ | |
| 404 void | |
| 405 OWCRC(uint8_t x, uint8_t *crc) { | |
| 406 *crc = pgm_read_byte(&dscrc_table[(*crc) ^ x]); | |
| 407 } | |
| 408 | |
| 409 /*----------------------------------------------------------------------------- | |
| 410 * Program a DS2502's memory | |
| 411 * | |
| 412 * Arguments | |
| 413 * ROM - ROM ID (or NULL to send SKIP_ROM) | |
| 414 * start - Start address (bytes) | |
| 415 * len - Length of data to write | |
| 416 * data - Data to write | |
| 417 * exact - If true, only accept exact matches for programming, | |
| 418 * otherwise only ensure the bits we requested were | |
| 419 * programmed [to 0] | |
| 420 * status - If true program status rather than memory | |
| 421 * | |
| 422 * Returns.. | |
| 423 * 0 if all is OK | |
| 424 * 1 if the programming is not possible | |
| 425 * 2 if the parameters were invalid | |
| 426 * 3 if the DS2502 didn't respond appropriately (also happens if the | |
| 427 * module doesn't exist) | |
| 428 */ | |
|
13
6f8f7b87d2f1
- Rename 1wire config example to note it's for AVR.
Daniel O'Connor <darius@dons.net.au>
parents:
0
diff
changeset
|
429 #if defined(OWSETVPPON) && defined(OWSETVPPOFF) |
| 0 | 430 uint8_t |
| 431 OWProgROM(uint8_t *ROM, uint8_t start, uint8_t len, uint8_t *data, uint8_t exact, uint8_t status) { | |
| 432 uint8_t crc, i, tmp; | |
| 433 | |
| 434 /* Stupid programmer detection */ | |
| 435 if (status) { | |
| 436 if (start + len > 3) | |
| 437 return(2); | |
| 438 } else { | |
| 439 if (start + len > 127) | |
| 440 return(2); | |
| 441 } | |
| 442 | |
| 443 if (len < 1) | |
| 444 return(2); | |
| 445 | |
| 446 OWDELAY_I; | |
| 447 if (OWTouchReset() != 0) { | |
| 448 cons_putsP(PSTR("No presence pulse\r\n")); | |
| 449 return(3); | |
| 450 } | |
| 451 | |
| 452 crc = 0; | |
| 453 | |
| 454 /* Send the command */ | |
| 455 if (status) { | |
| 456 OWSendCmd(ROM, OW_WRITE_STATUS); | |
| 457 OWCRC(OW_WRITE_STATUS, &crc); | |
| 458 } else { | |
| 459 OWSendCmd(ROM, OW_WRITE_MEMORY); | |
| 460 OWCRC(OW_WRITE_MEMORY, &crc); | |
| 461 } | |
| 462 | |
| 463 /* And the start address | |
| 464 * (2 bytes even though one would do) | |
| 465 */ | |
| 466 OWWriteByte(start); | |
| 467 OWCRC(start, &crc); | |
| 468 | |
| 469 OWWriteByte(0x00); | |
| 470 OWCRC(0x00, &crc); | |
| 471 | |
| 472 for (i = 0; i < len; i++) { | |
| 473 cons_putsP(PSTR("Programming ")); | |
| 474 cons_puts_hex(data[i]); | |
| 475 cons_putsP(PSTR(" to ")); | |
| 476 cons_puts_hex(start + i); | |
| 477 cons_putsP(PSTR("\r\n")); | |
| 478 | |
| 479 OWWriteByte(data[i]); | |
| 480 OWCRC(data[i], &crc); | |
| 481 | |
| 482 tmp = OWReadByte(); | |
| 483 | |
| 484 if (crc != tmp) { | |
| 485 cons_putsP(PSTR("CRC mismatch ")); | |
| 486 cons_puts_hex(crc); | |
| 487 cons_putsP(PSTR(" vs ")); | |
| 488 cons_puts_hex(tmp); | |
| 489 cons_putsP(PSTR("\r\n")); | |
| 490 | |
| 491 OWTouchReset(); | |
| 492 return(3); | |
| 493 } | |
| 494 | |
| 495 OWSETVPPON(); | |
| 496 OWDELAY_H; | |
| 497 OWSETVPPOFF(); | |
| 498 | |
| 499 tmp = OWReadByte(); | |
| 500 | |
| 501 /* Check the bits we turned off are off */ | |
| 502 /* | |
| 503 for (i = 0; i < 8; i++) | |
| 504 if (!(data[i] & 1 << i) && (tmp & 1 << i)) | |
| 505 return(-3); | |
| 506 */ | |
| 507 if ((!data[i] & tmp) != 0) { | |
| 508 cons_putsP(PSTR("Readback mismatch ")); | |
| 509 cons_puts_hex(data[i]); | |
| 510 cons_putsP(PSTR(" vs ")); | |
| 511 cons_puts_hex(data[i]); | |
| 512 cons_putsP(PSTR("\r\n")); | |
| 513 | |
| 514 OWTouchReset(); | |
| 515 return(3); | |
| 516 } | |
| 517 | |
| 518 /* The DS2502 loads it's CRC register with the address of the | |
| 519 * next byte */ | |
| 520 crc = 0; | |
| 521 OWCRC(start + i + 1, &crc); | |
| 522 } | |
| 523 | |
| 524 return(0); | |
|
13
6f8f7b87d2f1
- Rename 1wire config example to note it's for AVR.
Daniel O'Connor <darius@dons.net.au>
parents:
0
diff
changeset
|
525 } |
| 0 | 526 #else |
|
13
6f8f7b87d2f1
- Rename 1wire config example to note it's for AVR.
Daniel O'Connor <darius@dons.net.au>
parents:
0
diff
changeset
|
527 uint8_t |
|
6f8f7b87d2f1
- Rename 1wire config example to note it's for AVR.
Daniel O'Connor <darius@dons.net.au>
parents:
0
diff
changeset
|
528 OWProgROM(uint8_t *ROM __attribute((unused)), uint8_t start __attribute((unused)), uint8_t len __attribute((unused)), uint8_t *data __attribute((unused)), uint8_t exact __attribute((unused)), uint8_t status __attribute((unused))) { |
| 0 | 529 return(1); |
|
13
6f8f7b87d2f1
- Rename 1wire config example to note it's for AVR.
Daniel O'Connor <darius@dons.net.au>
parents:
0
diff
changeset
|
530 } |
| 0 | 531 #endif |
| 532 | |
| 533 /* | |
| 534 * OWGetTemp | |
| 535 * | |
| 536 * Get the temperature from a 1wire bus module | |
| 537 * | |
| 538 * Returns temperature in hundredths of a degree or OW_TEMP_xxx on | |
| 539 * error. | |
| 540 */ | |
| 541 int16_t | |
| 542 OWGetTemp(uint8_t *ROM) { | |
| 543 int8_t i; | |
| 544 uint8_t crc, buf[9]; | |
| 545 int16_t temp; | |
| 546 int16_t tfrac; | |
| 547 | |
| 548 if (ROM[0] != OW_FAMILY_TEMP) | |
| 549 return OW_TEMP_WRONG_FAM; | |
| 550 | |
| 551 OWSendCmd(ROM, OW_CONVERTT_CMD); | |
| 552 | |
| 553 i = 0; | |
| 554 | |
| 555 /* Wait for the conversion */ | |
| 556 while (OWReadBit() == 0) | |
| 557 i = 1; | |
| 558 | |
| 559 /* Check that we talked to a module and it did something */ | |
| 560 if (i == 0) { | |
| 561 return OW_TEMP_NO_ROM; | |
| 562 } | |
| 563 | |
| 564 OWSendCmd(ROM, OW_RD_SCR_CMD); | |
| 565 crc = 0; | |
| 566 for (i = 0; i < 8; i++) { | |
| 567 buf[i] = OWReadByte(); | |
| 568 OWCRC(buf[i], &crc); | |
| 569 } | |
| 570 buf[i] = OWReadByte(); | |
| 571 if (crc != buf[8]) | |
| 572 return OW_TEMP_CRC_ERR; | |
| 573 temp = buf[0]; | |
| 574 if (buf[1] & 0x80) | |
| 575 temp -= 256; | |
| 576 | |
| 577 /* Chop off 0.5 degree bit */ | |
| 578 temp >>= 1; | |
| 579 | |
| 580 /* Calulate the fractional remainder */ | |
| 581 tfrac = buf[7] - buf[6]; | |
| 582 | |
| 583 /* Work in 100'th of degreess to save on floats */ | |
| 584 tfrac *= (int16_t)100; | |
| 585 | |
| 586 /* Divide by count */ | |
| 587 tfrac /= buf[7]; | |
| 588 | |
| 589 /* Subtract 0.25 deg from temp */ | |
| 590 tfrac += 75; | |
| 591 if (tfrac < 100) | |
| 592 temp--; | |
| 593 else | |
| 594 tfrac -= 100; | |
| 595 | |
| 596 i = temp; | |
| 597 temp *= 100; | |
| 598 temp += tfrac; | |
| 599 | |
| 600 return(temp); | |
| 601 } | |
| 602 | |
| 603 /* | |
| 604 * OWTempStatusStr | |
| 605 * | |
| 606 * Return a string for each OW_TEMP_xxx error code | |
| 607 * | |
| 608 * shrt = 1 returns short strings | |
| 609 * | |
| 610 */ | |
| 611 const char * | |
| 612 OWTempStatusStr(int16_t val, uint8_t shrt) { | |
| 613 if (val > OW_TEMP_BADVAL) { | |
| 614 if (shrt) | |
| 615 return PSTR("OK"); | |
| 616 else | |
| 617 return PSTR("OK"); | |
| 618 } | |
| 619 | |
| 620 switch (val) { | |
| 621 case OW_TEMP_WRONG_FAM: | |
| 622 if (shrt) | |
| 623 return PSTR("WrFam"); | |
| 624 else | |
| 625 return PSTR("Wrong family"); | |
| 626 break; | |
| 627 case OW_TEMP_CRC_ERR: | |
| 628 if (shrt) | |
| 629 return PSTR("CRCErr"); | |
| 630 else | |
| 631 return PSTR("CRC Error"); | |
| 632 break; | |
| 633 case OW_TEMP_NO_ROM: | |
| 634 if (shrt) | |
| 635 return PSTR("NoROM"); | |
| 636 else | |
| 637 return PSTR("ROM did not reply"); | |
| 638 break; | |
| 639 default: | |
| 640 if (shrt) | |
| 641 return PSTR("???"); | |
| 642 else | |
| 643 return PSTR("Unknown error code"); | |
| 644 break; | |
| 645 } | |
| 646 } |