frederic blanc
onewire 1-wire ds18x20 ds2450 multi-channel
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onewire.cpp
00001 /** 00002 * @file onewire.c 00003 * @brief library 1-Wire(www.maxim-ic.com) 00004 * @author Maciej Rajtar (Published 10 May 2010 www.mbed.org) 00005 * @author Frederic BLANC (Published 01/03/2012 www.mbed.org) 00006 */ 00007 00008 #include "mbed.h" 00009 #include "onewire.h" 00010 00011 DigitalInOut ow_pin(p21); 00012 DigitalInOut ow_0(p21); 00013 DigitalInOut ow_1(p22); 00014 DigitalInOut ow_2(p23); 00015 DigitalInOut ow_3(p24); 00016 DigitalInOut* t_ow[4]={&ow_0,&ow_1,&ow_2,&ow_3}; 00017 //********************************************************************************************************** 00018 //* show_id 00019 //********************************************************************************************************** 00020 00021 00022 /** 00023 * @brief show_id 00024 * @param [in] id[] = rom_code 00025 * @return [out] text id 00026 * @date 20/06/2011 00027 */ 00028 string ow_show_id( uint8_t id[]) { 00029 00030 char hex[4]; 00031 string text (""); 00032 sprintf(hex,"%2.2X",id[0]); 00033 text+=hex; 00034 for (int i = OW_ROMCODE_SIZE-2; i >=1 ; --i ) { 00035 sprintf(hex,"%2.2X",id[i]); 00036 text+=hex; 00037 } 00038 sprintf(hex,"%2.2X",id[OW_ROMCODE_SIZE-1]); 00039 text+=hex; 00040 return text; 00041 } 00042 00043 //********************************************************************************************************** 00044 //* search_sensors 00045 //********************************************************************************************************** 00046 00047 /** 00048 * @brief search_sensors 00049 * @param [out] nSensors number of device onewire 00050 * @param [out] gSensorIDs[][] array of id romcode 00051 * @return OW_OK or OW_PRESENCE_ERR or OW_DATA_ERR 00052 * @date 20/06/2011 00053 */ 00054 uint8_t search_sensors(uint8_t *nSensors,uint8_t gSensorIDs[][OW_ROMCODE_SIZE] ) { 00055 00056 00057 uint8_t i; 00058 uint8_t id[OW_ROMCODE_SIZE]; 00059 uint8_t diff; 00060 printf( "Scanning Bus\n" ); 00061 diff = OW_SEARCH_FIRST; 00062 for (*nSensors = 0 ; (diff != OW_LAST_DEVICE) && (*nSensors < MAXSENSORS) ;++(*nSensors) ) { 00063 ow_find_sensor( &diff, &id[0] ); 00064 if ( diff == OW_PRESENCE_ERR ) { 00065 printf( "No Sensor found\r\n" ); 00066 return diff; 00067 } 00068 if ( diff == OW_DATA_ERR ) { 00069 printf( "Bus Error\r\n" ); 00070 return diff; 00071 } 00072 for (i=0;i<OW_ROMCODE_SIZE;i++) 00073 gSensorIDs[*nSensors][i]=id[i]; 00074 00075 } 00076 return OW_OK; 00077 } 00078 /** 00079 * @brief search_sensors 00080 * @param [in] n num bus onewire 00081 * @param [out] nSensors number of device onewire 00082 * @param [out] gSensorIDs[][][] array of id romcode 00083 * @return OW_OK or OW_PRESENCE_ERR or OW_DATA_ERR 00084 * @date 02/09/2011 00085 */ 00086 uint8_t search_sensors(uint8_t n,uint8_t *nSensors,uint8_t gSensorIDs[][MAXSENSORS][OW_ROMCODE_SIZE] ) { 00087 00088 00089 uint8_t i; 00090 uint8_t id[OW_ROMCODE_SIZE]; 00091 uint8_t diff; 00092 printf( "Scanning Bus %d\r\n",n ); 00093 diff = OW_SEARCH_FIRST; 00094 for (*nSensors = 0 ; (diff != OW_LAST_DEVICE) && (*nSensors < MAXSENSORS) ;++(*nSensors) ) { 00095 ow_find_sensor(n, &diff, &id[0] ); 00096 if ( diff == OW_PRESENCE_ERR ) { 00097 printf( "No Sensor found\r\n" ); 00098 return diff; 00099 } 00100 if ( diff == OW_DATA_ERR ) { 00101 printf( "Bus Error\r\n" ); 00102 return diff; 00103 } 00104 for (i=0;i<OW_ROMCODE_SIZE;i++) 00105 gSensorIDs[n][*nSensors][i]=id[i]; 00106 00107 } 00108 return OW_OK; 00109 } 00110 //********************************************************************************************************** 00111 //* find Sensors on 1-Wire-Bus 00112 //********************************************************************************************************** 00113 00114 /** 00115 * @brief find Sensors on 1-Wire-Bus 00116 * @param [in/out] diff is the result of the last rom-search 00117 * @param [out] is the rom-code of the sensor found 00118 * @return OW_OK or OW_ERROR 00119 * @date 20/06/2011 00120 */ 00121 uint8_t ow_find_sensor(uint8_t *diff, uint8_t id[]) { 00122 for (;;) 00123 { 00124 *diff = ow_rom_search( *diff, &id[0] ); 00125 if ( *diff==OW_PRESENCE_ERR) 00126 return OW_ERROR; 00127 if ( *diff==OW_DATA_ERR ) 00128 return OW_ERROR; 00129 if ( *diff == OW_LAST_DEVICE ) 00130 return OW_OK ; 00131 if ( id[0] == DS18B20_ID || id[0] == DS18S20_ID ) 00132 return OW_OK ; 00133 if ( id[0] == DS2450_ID ) 00134 return OW_OK ; 00135 } 00136 } 00137 00138 /** 00139 * @brief find Sensors on 1-Wire-Bus 00140 * @param [in] num bus onewire 00141 * @param [in/out] diff is the result of the last rom-search 00142 * @param [out] is the rom-code of the sensor found 00143 * @return OW_OK or OW_ERROR 00144 * @date 30/08/2011 00145 */ 00146 uint8_t ow_find_sensor(uint8_t n,uint8_t *diff, uint8_t id[]) { 00147 for (;;) 00148 { 00149 *diff = ow_rom_search(n, *diff, &id[0] ); 00150 if ( *diff==OW_PRESENCE_ERR) 00151 return OW_ERROR; 00152 if ( *diff==OW_DATA_ERR ) 00153 return OW_ERROR; 00154 if ( *diff == OW_LAST_DEVICE ) 00155 return OW_OK ; 00156 if ( id[0] == DS18B20_ID || id[0] == DS18S20_ID ) 00157 return OW_OK ; 00158 if ( id[0] == DS2450_ID ) 00159 return OW_OK ; 00160 } 00161 } 00162 //********************************************************************************************************** 00163 //* search romcode 00164 //********************************************************************************************************** 00165 00166 /** 00167 * @brief search romcode 00168 * @param [in] uint8_t diff 00169 * @param [out] id romcode 00170 * @return next_diff or OW_LAST_DEVICE or OW_DATA_ERR or OW_PRESENCE_ERR 00171 * @date 20/06/2011 00172 */ 00173 uint8_t ow_rom_search( uint8_t diff, uint8_t id[] ) { 00174 uint8_t i, j, next_diff; 00175 uint8_t b; 00176 00177 if ( ow_reset() ) 00178 return OW_PRESENCE_ERR; // error, no device found 00179 ow_byte_wr( OW_SEARCH_ROM ); // ROM search command 00180 next_diff = OW_LAST_DEVICE; // unchanged on last device 00181 i = OW_ROMCODE_SIZE * 8; // 8 bytes 00182 do { 00183 j = 8; // 8 bits 00184 do { 00185 b = ow_bit_io( 1 ); // read bit 00186 if ( ow_bit_io( 1 ) ) { // read complement bit 00187 if ( b ) // 11 00188 return OW_DATA_ERR; // data error 00189 } else { 00190 if ( !b ) { // 00 = 2 devices 00191 if ( diff > i || ((*id & 1) && diff != i) ) { 00192 b = 1; // now 1 00193 next_diff = i; // next pass 0 00194 } 00195 } 00196 } 00197 ow_bit_io( b ); // write bit 00198 *id >>= 1; 00199 if ( b ) 00200 *id |= 0x80; // store bit 00201 --i; 00202 } while ( --j ); 00203 id++; // next byte 00204 } while ( i ); 00205 return next_diff; // to continue search 00206 } 00207 /** 00208 * @brief search romcode 00209 * @param [in]n num bus onewire 00210 * @param [in] uint8_t diff 00211 * @param [out] id romcode 00212 * @return next_diff or OW_LAST_DEVICE or OW_DATA_ERR or OW_PRESENCE_ERR 00213 * @date 30/08/2011 00214 */ 00215 uint8_t ow_rom_search(uint8_t n, uint8_t diff, uint8_t id[] ) { 00216 uint8_t i, j, next_diff; 00217 uint8_t b; 00218 if ( ow_reset(n) ) 00219 return OW_PRESENCE_ERR; // error, no device found 00220 ow_byte_wr(n, OW_SEARCH_ROM ); // ROM search command 00221 next_diff = OW_LAST_DEVICE; // unchanged on last device 00222 i = OW_ROMCODE_SIZE * 8; // 8 bytes 00223 do { 00224 j = 8; // 8 bits 00225 do { 00226 b = ow_bit_io(n, 1 ); // read bit 00227 if ( ow_bit_io(n, 1 ) ) { // read complement bit 00228 if ( b ) // 11 00229 { 00230 00231 return OW_DATA_ERR; // data error 00232 } 00233 } else { 00234 if ( !b ) { // 00 = 2 devices 00235 if ( diff > i || ((*id & 1) && diff != i) ) { 00236 b = 1; // now 1 00237 next_diff = i; // next pass 0 00238 } 00239 } 00240 } 00241 ow_bit_io(n, b ); // write bit 00242 00243 *id >>= 1; 00244 if ( b ) 00245 *id |= 0x80; // store bit 00246 --i; 00247 } while ( --j ); 00248 id++; // next byte 00249 00250 } while ( i ); 00251 00252 00253 return next_diff; // to continue search 00254 } 00255 00256 00257 //********************************************************************************************************** 00258 //* test pin onewire bus 00259 //********************************************************************************************************** 00260 /** 00261 * @brief test pin onewire bus 00262 * @return etat pin ow 00263 * @date 20/06/2011 00264 */ 00265 uint8_t ow_test_pin (void){ 00266 if (ow_pin) 00267 return 1; 00268 return 0; 00269 } 00270 00271 /** 00272 * @brief test pin onewire bus 00273 * @param [in] num bus one wire 00274 * @return etat pin ow 00275 * @date 30/08/2011 00276 */ 00277 uint8_t ow_test_pin (uint8_t n){ 00278 00279 if (*t_ow[n]) 00280 return 1; 00281 return 0; 00282 } 00283 00284 //********************************************************************************************************** 00285 //* onewire reset bus 00286 //********************************************************************************************************** 00287 /** 00288 * @brief onewire reset bus 00289 * @return pin ow or OW_SHORT_CIRCUIT 00290 * @date 20/06/2011 00291 */ 00292 uint8_t ow_reset(void) { // reset. Should improve to act as a presence pulse 00293 uint8_t err; 00294 00295 ow_pin.output(); 00296 ow_pin = 0; // bring low for 500 us 00297 wait_us(500); 00298 ow_pin.input(); 00299 wait_us(60); 00300 err = ow_pin; 00301 wait_us(240); 00302 if ( ow_pin == 0 ) { // short circuit 00303 err = OW_SHORT_CIRCUIT; 00304 } 00305 return err; 00306 } 00307 00308 /** 00309 * @brief onewire reset bus 00310 * @param [in] num bus onewire 00311 * @return pin ow or OW_SHORT_CIRCUIT 00312 * @date 30/08/2011 00313 */ 00314 uint8_t ow_reset(uint8_t n) { // reset. Should improve to act as a presence pulse 00315 uint8_t err; 00316 00317 t_ow[n]->output(); 00318 *t_ow[n] = 0; // bring low for 500 us 00319 wait_us(500); 00320 t_ow[n]->input(); 00321 wait_us(60); 00322 err = *t_ow[n]; 00323 wait_us(240); 00324 if ( *t_ow[n] == 0 ) { // short circuit 00325 err = OW_SHORT_CIRCUIT; 00326 00327 } 00328 return err; 00329 } 00330 //********************************************************************************************************** 00331 //* read write onewire 00332 //********************************************************************************************************** 00333 /** 00334 * @brief read write onewire 00335 * @param [in/out] b data 00336 * @return data 00337 * @date 20/06/2011 00338 */ 00339 uint8_t ow_bit_io( uint8_t b ) { 00340 00341 ow_pin.output(); // drive bus low 00342 ow_pin = 0; 00343 wait_us(1); // Recovery-Time wuffwuff was 1 00344 00345 if ( b ) 00346 ow_pin.input(); // if bit is 1 set bus high (by ext. pull-up) 00347 // delay was 15uS-1 see comment above 00348 wait_us(15-1); 00349 if ( ow_pin == 0 ) b = 0; // sample at end of read-timeslot 00350 wait_us(60-15); 00351 ow_pin.input(); 00352 return b; 00353 } 00354 /** 00355 * @brief read write onewire 00356 * @param [in] n num bus onewire 00357 * @param [in/out] b data 00358 * @return data 00359 * @date 30/08/2011 00360 */ 00361 uint8_t ow_bit_io(uint8_t n, uint8_t b ) { 00362 00363 t_ow[n]->output(); // drive bus low 00364 *t_ow[n] = 0; 00365 wait_us(1); // Recovery-Time wuffwuff was 1 00366 00367 if ( b ) 00368 t_ow[n]->input(); // if bit is 1 set bus high (by ext. pull-up) 00369 // delay was 15uS-1 see comment above 00370 wait_us(15-1); 00371 if ( *t_ow[n] == 0 ) b = 0; // sample at end of read-timeslot 00372 wait_us(60-15); 00373 t_ow[n]->input(); 00374 // printf("ow_bit_io n=%d b=%X\n",n,b); 00375 return b; 00376 } 00377 //********************************************************************************************************** 00378 //* byte write on onewire 00379 //********************************************************************************************************** 00380 /** 00381 * @brief byte write on onewire 00382 * @param [in] b data 00383 * @return data 00384 * @date 20/06/2011 00385 */ 00386 uint8_t ow_byte_wr( uint8_t b ) { 00387 uint8_t i = 8, j; 00388 00389 do { 00390 j = ow_bit_io( b & 1 ); 00391 b >>= 1; 00392 if ( j ) 00393 b |= 0x80; 00394 } while ( --i ); 00395 return b; 00396 } 00397 /** 00398 * @brief byte write on onewire 00399 * @param [in] n num bus onewire 00400 * @param [in] b data 00401 * @return data 00402 * @date 30/08/2011 00403 */ 00404 uint8_t ow_byte_wr(uint8_t n, uint8_t b ) { 00405 uint8_t i = 8, j; 00406 00407 do { 00408 j = ow_bit_io(n, b & 1 ); 00409 b >>= 1; 00410 if ( j ) 00411 b |= 0x80; 00412 } while ( --i ); 00413 return b; 00414 } 00415 //********************************************************************************************************** 00416 //* byte write on onewire 00417 //********************************************************************************************************** 00418 /** 00419 * @brief byte read on onewire 00420 * @return data 00421 * @date 20/06/2011 00422 */ 00423 uint8_t ow_byte_rd( void ) { 00424 // read by sending 0xff (a dontcare?) 00425 return ow_byte_wr( 0xFF ); 00426 } 00427 00428 /** 00429 * @brief byte read on onewire 00430 * @param [in] n num onewire 00431 * @return data 00432 * @date 30/08/2011 00433 */ 00434 uint8_t ow_byte_rd( uint8_t n) { 00435 // read by sending 0xff (a dontcare?) 00436 return ow_byte_wr(n, 0xFF ); 00437 } 00438 //********************************************************************************************************** 00439 //* byte write on onewire 00440 //********************************************************************************************************** 00441 /** 00442 * @brief write command 00443 * @param [in] command 00444 * @param [in] id romcode 00445 * @date 20/06/2011 00446 */ 00447 uint8_t ow_command( uint8_t command, uint8_t id[] ) { 00448 uint8_t i; 00449 00450 ow_reset(); 00451 if ( id ) { 00452 ow_byte_wr( OW_MATCH_ROM ); // to a single device 00453 i = OW_ROMCODE_SIZE; 00454 do { 00455 ow_byte_wr( *id ); 00456 ++id; 00457 } while ( --i ); 00458 } else { 00459 ow_byte_wr( OW_SKIP_ROM ); // to all devices 00460 } 00461 ow_byte_wr( command ); 00462 return 0; 00463 } 00464 /** 00465 * @brief write command 00466 * @param [in] n num bus onewire 00467 * @param [in] command 00468 * @param [in] id romcode 00469 * @date 30/08/2011 00470 */ 00471 uint8_t ow_command(uint8_t n, uint8_t command, uint8_t id[] ) { 00472 uint8_t i; 00473 00474 ow_reset(n); 00475 if ( id ) { 00476 ow_byte_wr( n,OW_MATCH_ROM ); // to a single device 00477 i = OW_ROMCODE_SIZE; 00478 do { 00479 ow_byte_wr(n, *id ); 00480 ++id; 00481 } while ( --i ); 00482 } else { 00483 ow_byte_wr(n, OW_SKIP_ROM ); // to all devices 00484 } 00485 ow_byte_wr(n, command ); 00486 return 0; 00487 } 00488 //********************************************************************************************************** 00489 //* ow mode 00490 //********************************************************************************************************** 00491 /** 00492 * @brief parasite enable 00493 * @date 20/06/2011 00494 */ 00495 uint8_t ow_parasite_enable(void) { 00496 ow_pin.output(); 00497 ow_pin = 1; 00498 return 0; 00499 } 00500 /** 00501 * @brief parasite disable 00502 * @date 20/06/2011 00503 */ 00504 uint8_t ow_parasite_disable(void) { 00505 00506 ow_pin.input(); 00507 return 0; 00508 } 00509 00510 /** 00511 * @brief parasite enable 00512 * @param [in] n num bus onewire 00513 * @date 30/08/2011 00514 */ 00515 uint8_t ow_parasite_enable(uint8_t n) { 00516 t_ow[n]->output(); 00517 *t_ow[n] = 1; 00518 return 0; 00519 } 00520 /** 00521 * @brief parasite disable 00522 * @param [in] n num bus onewire 00523 * @date 30/08/2011 00524 */ 00525 uint8_t ow_parasite_disable(uint8_t n) { 00526 t_ow[n]->input(); 00527 return 0; 00528 } 00529 /** 00530 * @brief PUL-UP bus OW 00531 * @return OW_OK 00532 * @date 20/06/2011 00533 */ 00534 uint8_t ow_PullUp(void) 00535 { 00536 ow_pin.mode(PullUp); //PULL-UP bus OW 00537 return OW_OK; 00538 } 00539 /** 00540 * @brief PUL-UP bus OW 00541 * @param [in] n num bus onewire 00542 * @return OW_OK 00543 * @date 30/08/2011 00544 */ 00545 uint8_t ow_PullUp(uint8_t n) 00546 { 00547 t_ow[n]->mode(PullUp); //PULL-UP bus OW 00548 return OW_OK; 00549 }
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