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MAX31856
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MAX31856.h
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00001 /******************************************************************//** 00002 * @file MAX31856.h 00003 * 00004 * @author Devin Alexander 00005 * 00006 * @version 1.0 00007 * 00008 * Started: SEPTEMBER 14th 2017 00009 * 00010 * Updated: 00011 * 00012 * @brief Header file for MAX31856 class 00013 * 00014 *********************************************************************** 00015 * 00016 * @copyright 00017 * Copyright (C) 2017 Maxim Integrated Products, Inc., All Rights Reserved. 00018 * 00019 * Permission is hereby granted, free of charge, to any person obtaining a 00020 * copy of this software and associated documentation files (the "Software"), 00021 * to deal in the Software without restriction, including without limitation 00022 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 00023 * and/or sell copies of the Software, and to permit persons to whom the 00024 * Software is furnished to do so, subject to the following conditions: 00025 * 00026 * The above copyright notice and this permission notice shall be included 00027 * in all copies or substantial portions of the Software. 00028 * 00029 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 00030 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 00031 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 00032 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES 00033 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 00034 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 00035 * OTHER DEALINGS IN THE SOFTWARE. 00036 * 00037 * Except as contained in this notice, the name of Maxim Integrated 00038 * Products, Inc. shall not be used except as stated in the Maxim Integrated 00039 * Products, Inc. Branding Policy. 00040 * 00041 * The mere transfer of this software does not imply any licenses 00042 * of trade secrets, proprietary technology, copyrights, patents, 00043 * trademarks, maskwork rights, or any other form of intellectual 00044 * property whatsoever. Maxim Integrated Products, Inc. retains all 00045 * ownership rights. 00046 **********************************************************************/ 00047 00048 00049 #ifndef MAX31856_h 00050 #define MAX31856_h 00051 #include "mbed.h" 00052 00053 //***************************************************************************** 00054 //Define all the addresses of the registers in the MAX31856 00055 //***************************************************************************** 00056 #define ADDRESS_CR0_READ 0x00 //Factory Default 00h 00057 #define ADDRESS_CR0_WRITE 0x80 00058 #define ADDRESS_CR1_READ 0x01 //Factory Default 03h 00059 #define ADDRESS_CR1_WRITE 0x81 00060 #define ADDRESS_MASK_READ 0x02 //Factory Default FFh 00061 #define ADDRESS_MASK_WRITE 0x82 00062 #define ADDRESS_CJHF_READ 0x03 //Factory Default 7Fh 00063 #define ADDRESS_CJHF_WRITE 0x83 00064 #define ADDRESS_CJLF_READ 0x04 //Factory Default C0h 00065 #define ADDRESS_CJLF_WRITE 0x84 00066 #define ADDRESS_LTHFTH_READ 0x05 //Factory Default 7Fh 00067 #define ADDRESS_LTHFTH_WRITE 0x85 00068 #define ADDRESS_LTHFTL_READ 0x06 //Factory Default FFh 00069 #define ADDRESS_LTHFTL_WRITE 0x86 00070 #define ADDRESS_LTLFTH_READ 0x07 //Factory Default 80h 00071 #define ADDRESS_LTLFTH_WRITE 0x87 00072 #define ADDRESS_LTLFTL_READ 0x08 //Factory Default 00h 00073 #define ADDRESS_LTLFTL_WRITE 0x88 00074 #define ADDRESS_CJTO_READ 0x09 //Factory Default 00h 00075 #define ADDRESS_CJTO_WRITE 0x89 00076 #define ADDRESS_CJTH_READ 0x0A //Factory Default 00h 00077 #define ADDRESS_CJTH_WRITE 0x8A 00078 #define ADDRESS_CJTL_READ 0x0B //Factory Default 00h 00079 #define ADDRESS_CJTL_WRITE 0x8B 00080 #define ADDRESS_LTCBH_READ 0x0C 00081 #define ADDRESS_LTCBM_READ 0x0D 00082 #define ADDRESS_LTCBL_READ 0x0E 00083 #define ADDRESS_SR_READ 0x0F 00084 00085 //***************************************************************************** 00086 //Define parameters for control register zero (CR0) 00087 //***************************************************************************** 00088 #define CR0_CONV_MODE_NORMALLY_OFF 0x00 //Power On Default value 00089 #define CR0_CONV_MODE_NORMALLY_ON 0x80 00090 00091 #define CR0_1_SHOT_MODE_NO_CONVERSION 0x00 //defaults to this value 00092 #define CR0_1_SHOT_MODE_ONE_CONVERSION 0x40 //^ 00093 00094 #define CR0_OC_DETECT_DISABLED 0x00 00095 #define CR0_OC_DETECT_ENABLED_R_LESS_5k 0x10 00096 #define CR0_OC_DETECT_ENABLED_TC_LESS_2ms 0x20 00097 #define CR0_OC_DETECT_ENABLED_TC_MORE_2ms 0x30 00098 00099 #define CR0_COLD_JUNC_ENABLE 0x00 //Power On Default value 00100 #define CR0_COLD_JUNC_DISABLE 0x08 //speed of conversion is sped up by 25ms when this optionis selected (Disable the cold junc) 00101 00102 #define CR0_FAULT_MODE_COMPARATOR 0x00 //Power On Default value 00103 #define CR0_FAULT_MODE_INTERUPT 0x04 00104 00105 #define CR0_FAULTCLR_DEFAULT_VAL 0x00 //defaults to this value 00106 #define CR0_FAULTCLR_RETURN_FAULTS_TO_ZERO 0x02 //^ 00107 00108 #define CR0_FILTER_OUT_60Hz 0x00 //Preset value 00109 #define CR0_FILTER_OUT_50Hz 0x01 //^ 00110 00111 00112 //***************************************************************************** 00113 //Define parameters for control register one (CR1) 00114 //***************************************************************************** 00115 #define CR1_AVG_TC_SAMPLES_1 0x00 //Power on default value 00116 #define CR1_AVG_TC_SAMPLES_2 0x10 00117 #define CR1_AVG_TC_SAMPLES_4 0x20 00118 #define CR1_AVG_TC_SAMPLES_8 0x30 00119 #define CR1_AVG_TC_SAMPLES_16 0x40 00120 00121 // Define which type of thermocouple the MAX31856 is using. This is for lineariztion purposes 00122 #define CR1_TC_TYPE_B 0x00 00123 #define CR1_TC_TYPE_E 0x01 00124 #define CR1_TC_TYPE_J 0x02 00125 #define CR1_TC_TYPE_K 0x03 //Power on default value 00126 #define CR1_TC_TYPE_N 0x04 00127 #define CR1_TC_TYPE_R 0x05 00128 #define CR1_TC_TYPE_S 0x06 00129 #define CR1_TC_TYPE_T 0x07 00130 #define CR1_TC_TYPE_VOLT_MODE_GAIN_8 0x08 00131 #define CR1_TC_TYPE_VOLT_MODE_GAIN_32 0x0C 00132 00133 //***************************************************************************** 00134 //Define parameters for the mask register (MASK) 00135 //***************************************************************************** 00136 #define MASK_CJ_FAULT_THRESHOLD_HIGH 0x20 00137 #define MASK_CJ_FAULT_THRESHOLD_LOW 0x10 00138 #define MASK_TC_FAULT_THRESHOLD_HIGH 0x08 00139 #define MASK_TC_FAULT_THRESHOLD_LOW 0x04 00140 #define MASK_OVER_UNDER_VOLT_FAULT 0x02 00141 #define MASK_OPEN_CIRCUIT_FAULT 0x01 00142 00143 //***************************************************************************** 00144 //If these defined values are &= (bitwise ANDed) with the contents of a register, it will reset the bits pertaing to the specific bitfields to zero 00145 //***************************************************************************** 00146 #define CR0_CLEAR_BITS_7 ~(0x80) 00147 #define CR0_CLEAR_BITS_6 ~(0x40) 00148 #define CR0_CLEAR_BITS_5_4 ~(0x30) 00149 #define CR0_CLEAR_BITS_3 ~(0x08) 00150 #define CR0_CLEAR_BITS_2 ~(0x04) 00151 #define CR0_CLEAR_BITS_1 ~(0x02) 00152 #define CR0_CLEAR_BITS_0 ~(0x01) 00153 00154 #define CR1_CLEAR_BITS_6_4 ~(0x70) 00155 #define CR1_CLEAR_BITS_3_0 ~(0x0F) 00156 00157 #define MASK_CLEAR_BITS_5 ~(0x20) 00158 #define MASK_CLEAR_BITS_4 ~(0x10) 00159 #define MASK_CLEAR_BITS_3 ~(0x08) 00160 #define MASK_CLEAR_BITS_2 ~(0x04) 00161 #define MASK_CLEAR_BITS_1 ~(0x02) 00162 #define MASK_CLEAR_BITS_0 ~(0x01) 00163 00164 //***************************************************************************** 00165 ///Parameters that are used throughout the library 00166 //***************************************************************************** 00167 #define TC_MAX_VAL_FAULT 1800 00168 #define TC_MIN_VAL_FAULT -210 00169 #define CJ_MAX_VAL_FAULT 125 00170 #define CJ_MIN_VAL_FAULT -55 00171 00172 00173 00174 /** 00175 * @brief Library for the MAX31856\n 00176 * The MAX31856 thermocouple temperature sensor accurately measures temperature 00177 * and provides a vast amount of features such as: 00178 * //FEATURE 00179 * //FEATURE 00180 * //FEATURE 00181 * //FEATURE 00182 * //FEATURE 00183 * //FEATURE 00184 * Communication is through an SPI-compatible interface. 00185 * 00186 * @code 00187 * #include "mbed.h" 00188 * #include "MAX31856.h" 00189 * 00190 * 00191 * // Hardware serial port 00192 * Serial serial(USBTX, USBRX); 00193 * 00194 * //SPI communications 00195 * SPI spi(SPIO MOSI,SPIO MISO,SPIO SCK); 00196 * 00197 * //Thermocouples 00198 * MAX31856 Thermocouple1(spi, CHIPSELECT); 00199 * 00200 * 00201 * int main(void) 00202 * { 00203 * float temperature_TC_1, temperature_CJ_1; 00204 * while(true) 00205 * { 00206 * temperature_TC_1=Thermocouple1.readTC(); 00207 * temperature_CJ_1=Thermocouple1.readCJ(); 00208 * serial.printf("MAX31856 TC = %f Celsius MAX31856 CJ = %f Celsius \n\r",temperature_TC_1,temperature_CJ_1); 00209 * wait(1.0); 00210 * } 00211 * } 00212 * @endcode 00213 */ 00214 00215 00216 00217 /** Please see pages 18-26 in the MAX31856 data sheet to see what register bit masks are needed to be set 00218 to achieve functionality desired. The data sheet can be found at 00219 00220 *** https://datasheets.maximintegrated.com/en/ds/MAX31856.pdf *** 00221 */ 00222 00223 00224 /** 00225 * MAX31856 Class 00226 */ 00227 class MAX31856 00228 { 00229 00230 public: 00231 //***************************************************************************** 00232 //Constructor and Destructor for the class 00233 //***************************************************************************** 00234 /** 00235 * @brief Constructor to create MAX31856 object with SPI information as well as preconfiguration parameter settings in configuration registers Zero and One 00236 * @param _spi - Reference to SPI object 00237 * @param _ncs - Chip Select for SPI comunications with the oject 00238 * @param _type - Type of thermocouple used 00239 * @param _fltr - Feature of the MAX31856 to filter out either 50Hz/60Hz from signal 00240 * @param _samples - How many samples are averaged for one conversion 00241 * @param _conversion_mode - Choose between always on and making conversions and off in between requests for a reading 00242 */ 00243 MAX31856(SPI& _spi, PinName _ncs, uint8_t _type=CR1_TC_TYPE_K, uint8_t _fltr=CR0_FILTER_OUT_60Hz, uint8_t _samples=CR1_AVG_TC_SAMPLES_1, uint8_t _conversion_mode=CR0_CONV_MODE_NORMALLY_OFF); 00244 00245 00246 /** @brief Destructor */ 00247 ~MAX31856(void); 00248 00249 00250 //***************************************************************************** 00251 //Temperature Functions 00252 //***************************************************************************** 00253 /** 00254 * @brief Requests read of the thermocouple temperature 00255 * @return float of the converted thermocouple reading based on current configurations 00256 */ 00257 float readTC(); 00258 00259 00260 /** 00261 * @brief Requests read of the cold junction temperature 00262 * @return float of the converted artificial cold junction reading based on current configurations 00263 */ 00264 float readCJ(); 00265 00266 00267 //***************************************************************************** 00268 //Functions for register CR0 00269 //***************************************************************************** 00270 /** 00271 * @brief Sets bits in the configuration register zero for setting the rate of conversions 00272 * @param val \li CR0_CONV_MODE_NORMALLY_OFF (Power On Default value) 00273 * \li CR0_CONV_MODE_NORMALLY_ON 00274 * @return \li 1 on success 00275 * \li 0 if there is an incorrect parameter that is passed in as parameter val 00276 */ 00277 bool setConversionMode(uint8_t val); 00278 00279 00280 /** 00281 * @brief Sets bits in the configuration register zero for enabling one conversion to take place 00282 * @param val \li CR0_1_SHOT_MODE_NO_CONVERSION (Power On Default value) 00283 * \li CR0_1_SHOT_MODE_ONE_CONVERSION (This bit self clears itself to default back to CR0_1_SHOT_MODE_NO_CONVERSION after singular conversion takes place) 00284 * @return \li 1 on success 00285 * \li 0 if there is an incorrect parameter that is passed in as parameter val 00286 */ 00287 bool setOneShotMode(uint8_t val); 00288 00289 00290 /** 00291 * @brief Sets bits in the configuration register zero for configuring open circuit fault detection 00292 * @param val \li CR0_OC_DETECT_DISABLED (Power On Default value) 00293 * \li CR0_OC_DETECT_ENABLED_R_LESS_5k 00294 * \li CR0_OC_DETECT_ENABLED_TC_LESS_2ms 00295 * \li CR0_OC_DETECT_ENABLED_TC_MORE_2ms 00296 * @return \li 1 on success 00297 * \li 0 if there is an incorrect parameter that is passed in as parameter val 00298 */ 00299 bool setOpenCircuitFaultDetection(uint8_t val); 00300 00301 00302 /** 00303 * @brief Sets bits in the configuration register zero for disabling or enabling the Cold Junction 00304 * @param val \li CR0_COLD_JUNC_ENABLE (Power On Default value) 00305 * \li CR0_COLD_JUNC_DISABLE 00306 * @return \li 1 on success 00307 * \li 0 if there is an incorrect parameter that is passed in as parameter val 00308 */ 00309 bool setColdJunctionDisable(uint8_t val); 00310 00311 00312 /** 00313 * @brief Sets bits in the configuration register zero for setting fault mode status 00314 * @param val \li CR0_FAULT_MODE_COMPARATOR (Power On Default value) 00315 * \li CR0_FAULT_MODE_INTERUPT 00316 * @return \li 1 on success 00317 * \li 0 if there is an incorrect parameter that is passed in as parameter val 00318 */ 00319 bool setFaultMode(uint8_t val); 00320 00321 00322 /** 00323 * @brief Sets bits in the configuration register zero for clearing fault status 00324 * @param val \li CR0_FAULTCLR_DEFAULT_VAL (Power On Default value) 00325 * \li CR0_FAULTCLR_RETURN_FAULTS_TO_ZERO (This bit self clears itself to default back to CR0_FAULTCLR_DEFAULT_VAL after fault status is cleared) 00326 * @return \li 1 on success 00327 * \li 0 if there is an incorrect parameter that is passed in as parameter val 00328 */ 00329 bool setFaultStatusClear(uint8_t val); 00330 00331 00332 /** 00333 * @brief Sets bits in the configuration register zero for setting which of the two filter modes either 50Hz or 60Hz cancelation 00334 * @param val \li CR0_FILTER_OUT_60Hz (Power On Default value) 00335 * \li CR0_FILTER_OUT_50Hz 00336 * @return \li 1 on success 00337 * \li 0 if there is an incorrect parameter that is passed in as parameter val 00338 */ 00339 bool setEmiFilterFreq(uint8_t val); 00340 00341 00342 //***************************************************************************** 00343 //Functions for register CR1 00344 //***************************************************************************** 00345 /** 00346 * @brief Sets bits in the configuration register one for setting how many readings are taken 00347 * @param val \li CR1_AVG_TC_SAMPLES_1 (Power On Default value) 00348 * \li CR1_AVG_TC_SAMPLES_2 00349 * \li CR1_AVG_TC_SAMPLES_4 00350 * \li CR1_AVG_TC_SAMPLES_8 00351 * \li CR1_AVG_TC_SAMPLES_16 00352 * @return \li 1 on success 00353 * \li 0 if there is an incorrect parameter that is passed in as parameter val 00354 */ 00355 bool setNumSamplesAvg(uint8_t val); 00356 00357 00358 /** 00359 * @brief Sets bits in the configuration register one for setting which thermocouple type is going to be programmed into the MAX31856 for linearization of thermovoltage produced and temperature 00360 * @param val \li CR1_TC_TYPE_B 00361 * \li CR1_TC_TYPE_E 00362 * \li CR1_TC_TYPE_J 00363 * \li CR1_TC_TYPE_K (Power On Default value) 00364 * \li CR1_TC_TYPE_N 00365 * \li CR1_TC_TYPE_R 00366 * \li CR1_TC_TYPE_S 00367 * \li CR1_TC_TYPE_T 00368 * \li CR1_TC_TYPE_VOLT_MODE_GAIN_8 00369 * \li CR1_TC_TYPE_VOLT_MODE_GAIN_32 00370 * @return \li 1 on success 00371 * \li 0 if there is an incorrect parameter that is passed in as parameter val 00372 */ 00373 bool setThermocoupleType(uint8_t val); 00374 00375 00376 //***************************************************************************** 00377 //Functions for register MASK 00378 //***************************************************************************** 00379 /** 00380 * @brief Sets bits in the configuration register one for setting fault masks 00381 * @param val \li MASK_CJ_FAULT_THRESHOLD_HIGH 00382 * \li MASK_CJ_FAULT_THRESHOLD_LOW 00383 * \li MASK_TC_FAULT_THRESHOLD_HIGH 00384 * \li MASK_TC_FAULT_THRESHOLD_LOW 00385 * \li MASK_OVER_UNDER_VOLT_FAULT 00386 * \li MASK_OPEN_CIRCUIT_FAULT 00387 * @param enable \li 0 for disabling the mask in whichever option is selcted in parameter val 00388 * \li 1 for enabling the mask in whichever option is selcted in parameter val 00389 * @return \li 1 on success 00390 * \li 0 if there is an incorrect parameter that is passed in as parameter val 00391 */ 00392 bool setFaultMasks(uint8_t val, bool enable); 00393 00394 00395 /** 00396 * @brief Sets bits in the configuration register one for setting thresholds that corespond to the fault mask settings 00397 * @param val \li MASK_CJ_FAULT_THRESHOLD_HIGH 00398 * \li MASK_CJ_FAULT_THRESHOLD_LOW 00399 * \li MASK_TC_FAULT_THRESHOLD_HIGH 00400 * \li MASK_TC_FAULT_THRESHOLD_LOW 00401 * @param temperature value that you want to program into a threshold register for temperatre 00402 * @return return value that was programmed into the threshold register 00403 */ 00404 bool setFaultThresholds(uint8_t val, float temperature); 00405 00406 00407 //***************************************************************************** 00408 //Check Fault Status Functions 00409 //***************************************************************************** 00410 /** 00411 * @brief Check the fault stautus register to see if there is anything wrong with range of thermocouple temperature 00412 * whether outside opperating temperatures or if above/below thresholds that are set 00413 * @return \li 0 if no faults are present 00414 * \li 1 if Thermocouple temp is higher than the threshold 00415 * \li 2 if Thermocouple temp is lower than the threshold 00416 * \li 3 if Thermocouple temp is outside operating range of termocouple type 00417 * \li 4 if Thermocouple temp is higher than the threshold && is outside operating range of termocouple type 00418 * \li 5 if Thermocouple temp is lower than the threshold && is outside operating range of termocouple type 00419 */ 00420 uint8_t checkFaultsThermocoupleThresholds(); 00421 00422 00423 /** 00424 * @brief Check the fault stautus register to see if there is anything wrong with range of cold junction temperature 00425 * whether outside opperating temperatures or if above/below thresholds that are set 00426 * @return \li 0 if no faults are present 00427 * \li 1 if Cold Junction temp is higher than the threshold 00428 * \li 2 if Cold Junction temp is lower than the threshold 00429 * \li 3 if Cold Junction temp is outside operating range of termocouple type 00430 * \li 4 if Cold Junction temp is higher than the threshold && is outside operating range of termocouple type 00431 * \li 5 if Cold Junction temp is lower than the threshold && is outside operating range of termocouple type 00432 */ 00433 uint8_t checkFaultsColdJunctionThresholds(); 00434 00435 00436 /** 00437 * @brief Check the fault stautus register to see if there is anything wrong with thermocouple connection to the MAX31856 00438 * @return \li 1 if no faults are present 00439 * \li 0 if there is a fault and there needs to be information printed to the console to help diagnose issues 00440 */ 00441 bool checkFaultsThermocoupleConnection(); 00442 00443 00444 //***************************************************************************** 00445 //General Functions 00446 //***************************************************************************** 00447 /** 00448 * @brief This function is to read current contents of register, manipulate the contents, then rewrite the specific register\n 00449 * \li Read the value of a register from contents of register matching the parameter read_address 00450 * \li Clear the bits needed to be changed by bitwise ANDing the read value with the 8 bit parameter clear_bits 00451 * \li Set the bits of interest in the 8 bit value by bitwise ORing the value from step two with parameter val 00452 * \li Rewrite to the register with the new 8 bit value to the register with the address with parameter write_address 00453 * @param read_address - Address of register to read the data before it's changed 00454 * @param write_address - Address of register to rewrite the changed data 00455 * @param clear_bits - Parameter that is 00456 * @param val - Bitfield that contains bits related to function specific settings 00457 * @return \li 1 on success 00458 */ 00459 bool registerReadWriteByte(uint8_t read_address, uint8_t write_address, int clear_bits, uint8_t val); 00460 00461 00462 /** 00463 * @brief This function is to read current contents of register, manipulate the contents, then rewrite the specific register\n 00464 * \li Read the value of a register from contents of register matching the parameter read_address 00465 * \li Clear the bits needed to be changed by bitwise ANDing the read value with the 8 bit parameter clear_bits 00466 * \li Set the bits of interest in the 8 bit value by bitwise ORing the value from step two with parameter val 00467 * \li Write to the register with the new 8 bit value to the register with the address with parameter write_address 00468 * @param write_address - Address of register to rewrite the changed data 00469 * @param val - Byte of information that is going to be written to the regitser with the address that matches the parameter write_address 00470 * @return \li 1 on success 00471 */ 00472 bool registerWriteByte(uint8_t write_address, uint8_t val); 00473 00474 00475 /** 00476 * @brief This function is to read current contents of register by passing in the address of the read address and return contents of the register 00477 * @param read_address - Address of register to read data from 00478 * @return \li byte contained in the address 00479 */ 00480 uint8_t registerReadByte(uint8_t read_address); 00481 00482 00483 /** 00484 * @brief This function is to read current contents of register by passing in the address of the read address and return contents of the register 00485 * @param temperature - Float of value to offest the value of the cold junction offset by (must be between -8°C to +7.9375°C) 00486 * @return \li 1 on successfully updated coldjunction offset 00487 * \li 0 if parameter temperature does not fall between range -8°C to +7.9375°C 00488 */ 00489 bool coldJunctionOffset(float temperature); 00490 00491 00492 private: 00493 00494 //***************************************************************************** 00495 //Private Functions 00496 //***************************************************************************** 00497 /** @brief Writes the chip seleect pin low to begin SPI communications */ 00498 void spiEnable(); 00499 00500 00501 /** @brief Writes the chip seleect pin high to end SPI communications */ 00502 void spiDisable(); 00503 00504 /** @brief Calculates minimum wait time for a conversion to take place */ 00505 void calculateDelayTime(); 00506 00507 00508 //***************************************************************************** 00509 //Private Members 00510 //***************************************************************************** 00511 /// SPI object 00512 SPI& spi; 00513 00514 /// Chip select pin for SPI communications 00515 DigitalOut ncs; 00516 00517 /// Number of samples the thermocouple is configured to average 00518 uint8_t samples; 00519 00520 /// 0=thermocouple is set to one of 8 thermocouple types and 1=Thermocouple is configured to report in voltage mode 00521 bool voltage_mode; 00522 00523 /// 0=60Hz and 1=50Hz 00524 bool filter_mode; 00525 00526 /// 0=MAX31856 is off, so no conversion is taking place currently and 1=Always On and converting 00527 bool conversion_mode; 00528 00529 /// 0=cold junction is disabled and 1=cold junction is enabled 00530 bool cold_junction_enabled; 00531 00532 ///Define a return val for all boolean functions 00533 bool return_val; 00534 00535 ///Used to figure out when a new conversion is ready to go 00536 uint32_t lastReadTime; 00537 00538 ///How many conversions have taken place since conversion mode was switched into auto mode 00539 ///Also this value should be 0 if the mode is in oneshot mode 00540 uint32_t thermocouple_conversion_count; 00541 00542 ///time in milliseconds that is needed minimum for a new conversion to take place 00543 uint32_t conversion_time; 00544 }; 00545 00546 #endif /* __MAX31856_H_ */
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