Library for the MAX31856 Precision Thermocouple to Digital Converter with Linearization
Dependents: MAX31856_example_program
Fork of MAX31856 by
MAX31856.cpp
- Committer:
- DevinAlexander
- Date:
- 2017-09-14
- Revision:
- 1:a1bbb5c254f2
- Parent:
- 0:b714c6a7c969
File content as of revision 1:a1bbb5c254f2:
/******************************************************************//** * @file MAX31856.cpp * * @author Devin Alexander * * @version 1.0 * * Started: SEPTEMBER 14th 2017 * * Updated: * * @brief Source file for MAX3185 class * *********************************************************************** * * @copyright * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. * * Except as contained in this notice, the name of Maxim Integrated * Products, Inc. shall not be used except as stated in the Maxim Integrated * Products, Inc. Branding Policy. * * The mere transfer of this software does not imply any licenses * of trade secrets, proprietary technology, copyrights, patents, * trademarks, maskwork rights, or any other form of intellectual * property whatsoever. Maxim Integrated Products, Inc. retains all * ownership rights. **********************************************************************/ #include <mbed.h> #include "MAX31856.h" #define LOG(args...) printf(args) //***************************************************************************** MAX31856::MAX31856(SPI& _spi, PinName _ncs, uint8_t _type, uint8_t _fltr, uint8_t _samples, uint8_t _conversion_mode) : spi(_spi), ncs(_ncs), samples(_samples) { spi.format(8,3); //configure the correct SPI mode to beable to program the registers intially correctly setThermocoupleType(_type); setEmiFilterFreq(_fltr); setNumSamplesAvg(_samples); setConversionMode(_conversion_mode); } //***************************************************************************** float MAX31856::readTC() { //Check and see if the MAX31856 is set to conversion mode ALWAYS ON if (conversion_mode==0) { //means that the conversion mode is normally off setOneShotMode(CR0_1_SHOT_MODE_ONE_CONVERSION); // turn on the one shot mode for singular conversion thermocouple_conversion_count=0; //reset the conversion count back to zero to make sure minimum conversion time reflects one shot mode requirements } //calculate minimum wait time for conversions calculateDelayTime(); //initialize other info for the read functionality int32_t temp; uint8_t buf_read[3], buf_write[3]={ADDRESS_LTCBH_READ,ADDRESS_LTCBM_READ,ADDRESS_LTCBL_READ}; bool read_thermocouple_temp=checkFaultsThermocoupleConnection(); //check and see if there are any faults that prohibit a normal read of the register if(read_thermocouple_temp){ //no faults with connection are present so continue on with normal read of temperature uint32_t time = us_ticker_read(); uint32_t duration = time - lastReadTime; if (duration > conversion_time) { // more than current conversion time for(int i=0; i<3; i++) { spiEnable(); buf_read[i]=spi.write(buf_write[i]); buf_read[i]=spi.write(buf_write[i]); spiDisable(); } //Convert the registers contents into the correct value temp =((buf_read[0] & 0xFF) << 11); //Shift Byte 2 into place temp|=((buf_read[1] & 0xFF) << 3); //Shift Byte 1 into place temp|=((buf_read[2] & 0xFF) >> 5); //Shift Byte 0 into place float val=(temp/128.0f); //Divide the binary string by 2 to the 7th power return val; } } thermocouple_conversion_count++; //iterate the conversion count to speed up time in between future converions in always on mode checkFaultsThermocoupleThresholds(); //print any faults to the terminal return 0; } //***************************************************************************** float MAX31856::readCJ() { int32_t temp; uint8_t buf_read[3], buf_write=ADDRESS_CJTH_READ; spiEnable(); for(int i=0; i<3; i++) { buf_read[i]=spi.write(buf_write); } spiDisable(); //Convert the registers contents into the correct value temp =((int32_t)(buf_read[1] << 6)); //Shift the MSB into place temp|=((int32_t)(buf_read[2] >> 2)); //Shift the LSB into place float val=((float)(temp/64.0)); //Divide the binary string by 2 to the 6th power checkFaultsColdJunctionThresholds(); //print any faults to the terminal return val; } //***************************************************************************** uint8_t MAX31856::checkFaultsThermocoupleThresholds() { uint8_t fault_byte=registerReadByte(ADDRESS_SR_READ); //Read contents of fault status register uint8_t temp[2], return_int; for(int i=0; i<2; i++) temp[i]=fault_byte; //Check if any of the faults for thermocouple connection are triggered if ((fault_byte&0x4C)==0) //means no fault is detected for thermocouple thresholds return_int=0; else { if ((fault_byte&0x40)==0) { //check if normal operation of thermocouple is true if (temp[0]&0x08) { LOG("FAULT! Thermocouple temp is higher than the threshold that is set!\r\n"); return_int=1; } else if (temp[1]&0x04) { LOG("FAULT! Thermocouple temp is lower than the threshold that is set!\r\n"); return_int=2; } } else { //Thermocouples is operating outside of normal range LOG("FAULT! Thermocouple temperature is out of range for specific type of thermocouple!\r\n"); if (temp[0]&0x08) { LOG("FAULT! Thermocouple temp is higher than the threshold that is set!\r\n"); return_int=4; } else if (temp[1]&0x04) { LOG("FAULT! Thermocouple temp is lower than the threshold that is set!\r\n"); return_int=5; } else //no other faults are flagged besides unnatural operation return_int=3; } } return return_int; } //***************************************************************************** uint8_t MAX31856::checkFaultsColdJunctionThresholds() { uint8_t fault_byte=registerReadByte(ADDRESS_SR_READ); //Read contents of fault status register uint8_t temp[2], return_int; for(int i=0; i<2; i++) temp[i]=fault_byte; //Check if any of the faults for thermocouple connection are triggered if ((fault_byte&0xB0)==0) //means no fault is detected for cold junction thresholds return_int=0; else { if ((fault_byte&0x80)==0) { //check if normal operation of cold junction is true if (temp[0]&0x20) { LOG("FAULT! Cold Junction temp is higher than the threshold that is set!\r\n"); return_int=1; } else if (temp[1]&0x10) { LOG("FAULT! Cold Junction temp is lower than the threshold that is set!\r\n"); return_int=2; } } else { //Cold Junction is operating outside of normal range LOG("FAULT! Cold Junction temperature is out of range for specific type of thermocouple!\r\n"); if (temp[0]&0x20) { LOG("FAULT! Cold Junction temp is higher than the threshold that is set!\r\n"); return_int=4; } else if (temp[1]&0x10) { LOG("FAULT! Cold Junction temp is lower than the threshold that is set!\r\n"); return_int=5; } else //no other faults are flagged besides unnatural operation return_int=3; } } return return_int; } //***************************************************************************** bool MAX31856::checkFaultsThermocoupleConnection() { uint8_t fault_byte=registerReadByte(ADDRESS_SR_READ); //Read contents of fault status register uint8_t temp[2]; for(int i=0; i<2; i++) temp[i]=fault_byte; //Check if any of the faults for thermocouple connection are triggered if (fault_byte==0) //means no fault is detected return_val=1; else{ if (temp[0]&0x02) { LOG("Overvotage/Undervoltage Fault triggered! Input voltage is negative or the voltage is greater than Vdd! Please check thermocouple connection!\r\n"); return_val=0; } if (temp[1]&0x01) { LOG("Open circuit fault detected! Please check thermocouple connection!\r\n"); return_val=0; } } return return_val; } //Register:CR0 Bits: 7 //***************************************************************************** bool MAX31856::setConversionMode(uint8_t val) { if (val==CR0_CONV_MODE_NORMALLY_OFF) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_7, val); conversion_mode=0; LOG("Register containing\t\tsetConversionMode\t\twas programmed with the parameter\t\tCR0_CONV_MODE_NORMALLY_OFF\r\n"); } else if (val==CR0_CONV_MODE_NORMALLY_ON) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_7, val); conversion_mode=1; LOG("Register containing\t\tsetConversionMode\t\twas programmed with the parameter\t\tCR0_CONV_MODE_NORMALLY_ON\r\n"); } else { LOG("Incorrect parameter selected for Control Register 0 (CR0) bit 7. Default value not changed.\r\nPlease see MAX31856.h for list of valid parameters. \r\n"); return_val=0; //returns a 0 to flag that the parameter wasn't programmed due to wrong parameter in function call } return return_val; } //Register:CR0 Bits: 6 //***************************************************************************** bool MAX31856::setOneShotMode(uint8_t val) { if (val==CR0_1_SHOT_MODE_NO_CONVERSION) return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_6, val); else if (val==CR0_1_SHOT_MODE_ONE_CONVERSION) return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_6, val); else { LOG("Incorrect parameter selected for Control Register 0 (CR0) bit 6. Default value not changed.\r\nPlease see MAX31856.h for list of valid parameters. \r\n"); return_val=0; //returns a 0 to flag that the parameter wasn't programmed due to wrong parameter in function call } return return_val; } //Register:CR0 Bits: 5:4 //***************************************************************************** bool MAX31856::setOpenCircuitFaultDetection(uint8_t val) { if (val==CR0_OC_DETECT_DISABLED) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_5_4, val); LOG("Register containing\t\tsetOpenCircuitFaultDetection\t\twas programmed with the parameter\t\tCR0_OC_DETECT_DISABLED\r\n"); } else if (val==CR0_OC_DETECT_ENABLED_R_LESS_5k) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_5_4, val); LOG("Register containing\t\tsetOpenCircuitFaultDetection\t\twas programmed with the parameter\t\tCR0_OC_DETECT_ENABLED_R_LESS_5k\r\n"); } else if (val==CR0_OC_DETECT_ENABLED_TC_LESS_2ms) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_5_4, val); LOG("Register containing\t\tsetOpenCircuitFaultDetection\t\twas programmed with the parameter\t\tCR0_OC_DETECT_ENABLED_TC_LESS_2ms\r\n"); } else if (val==CR0_OC_DETECT_ENABLED_TC_MORE_2ms) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_5_4, val); LOG("Register containing\t\tsetOpenCircuitFaultDetection\t\twas programmed with the parameter\t\tCR0_OC_DETECT_ENABLED_TC_MORE_2ms\r\n"); } else { LOG("Incorrect parameter selected for Control Register 0 (CR0) bits 5:4. Default value not changed.\r\nPlease see MAX31856.h for list of valid parameters. \r\n"); return_val=0; //returns a 0 to flag that the parameter wasn't programmed due to wrong parameter in function call } return return_val; } //Register:CR0 Bits: 3 //***************************************************************************** bool MAX31856::setColdJunctionDisable(uint8_t val) { if (val==CR0_COLD_JUNC_ENABLE) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_3, val); cold_junction_enabled=1; LOG("Register containing\t\tsetColdJunctionDisable\t\twas programmed with the parameter\t\tCR0_COLD_JUNC_ENABLE\r\n"); } else if (val==CR0_COLD_JUNC_DISABLE) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_3, val); cold_junction_enabled=0; LOG("Register containing\t\tsetColdJunctionDisable\t\twas programmed with the parameter\t\tCR0_COLD_JUNC_DISABLE\r\n"); } else { LOG("Incorrect parameter selected for Control Register 0 (CR0) bit 3. Default value not changed.\r\nPlease see MAX31856.h for list of valid parameters. \r\n"); return_val=0; //returns a 0 to flag that the parameter wasn't programmed due to wrong parameter in function call } return return_val; } //Register:CR0 Bits: 2 //***************************************************************************** bool MAX31856::setFaultMode(uint8_t val) { if (val==CR0_FAULT_MODE_COMPARATOR) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_2, val); LOG("Register containing\t\tsetFaultMode\t\twas programmed with the parameter\t\tCR0_FAULT_MODE_COMPARATOR\r\n"); } else if (val==CR0_FAULT_MODE_INTERUPT) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_2, val); LOG("Register containing\t\tsetFaultMode\t\twas programmed with the parameter\t\tCR0_FAULT_MODE_INTERUPT\r\n"); } else { LOG("Incorrect parameter selected for Control Register 0 (CR0) bit 2. Default value not changed.\r\nPlease see MAX31856.h for list of valid parameters. \r\n"); return_val=0; //returns a 0 to flag that the parameter wasn't programmed due to wrong parameter in function call } return return_val; } //Register:CR0 Bits: 1 //***************************************************************************** bool MAX31856::setFaultStatusClear(uint8_t val) { if (val==CR0_FAULTCLR_DEFAULT_VAL) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_1, val); LOG("Register containing\t\tsetFaultStatusClear\t\twas programmed with the parameter\t\tCR0_FAULTCLR_DEFAULT_VAL\r\n"); } else if (val==CR0_FAULTCLR_RETURN_FAULTS_TO_ZERO) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_1, val); LOG("Register containing\t\tsetFaultStatusClear\t\twas programmed with the parameter\t\tCR0_FAULTCLR_RETURN_FAULTS_TO_ZERO\r\n"); } else { LOG("Incorrect parameter selected for Control Register 0 (CR0) bit 1. Default value not changed.\r\nPlease see MAX31856.h for list of valid parameters. \r\n"); return_val=0; //returns a 0 to flag that the parameter wasn't programmed due to wrong parameter in function call } return return_val; } //Register:CR0 Bits: 0 //***************************************************************************** bool MAX31856::setEmiFilterFreq(uint8_t val) { if (val==CR0_FILTER_OUT_60Hz) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_0, val); filter_mode=0; LOG("Register containing\t\tsetEmiFilterFreq\t\twas programmed with the parameter\t\tCR0_FILTER_OUT_60Hz\r\n"); } else if (val==CR0_FILTER_OUT_50Hz) { return_val=registerReadWriteByte(ADDRESS_CR0_READ, ADDRESS_CR0_WRITE, CR0_CLEAR_BITS_0, val); filter_mode=1; LOG("Register containing\t\tsetEmiFilterFreq\t\twas programmed with the parameter\t\tCR0_FILTER_OUT_50Hz\r\n"); } else { LOG("Incorrect parameter selected for Control Register 0 (CR0) bit 0. Default value not changed.\r\nPlease see MAX31856.h for list of valid parameters. \r\n"); return_val=0; //returns a 0 to flag that the parameter wasn't programmed due to wrong parameter in function call } return return_val; } //Register:CR1 Bits: 6:4 //***************************************************************************** bool MAX31856::setNumSamplesAvg(uint8_t val) { if (val==CR1_AVG_TC_SAMPLES_1) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_6_4, val); samples=1; LOG("Register containing\t\tsetNumSamplesAvg\t\twas programmed with the parameter\t\tCR1_AVG_TC_SAMPLES_1\r\n"); } else if (val==CR1_AVG_TC_SAMPLES_2) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_6_4, val); samples=2; LOG("Register containing\t\tsetNumSamplesAvg\t\twas programmed with the parameter\t\tCR1_AVG_TC_SAMPLES_2\r\n"); } else if (val==CR1_AVG_TC_SAMPLES_4) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_6_4, val); samples=4; LOG("Register containing\t\tsetNumSamplesAvg\t\twas programmed with the parameter\t\tCR1_AVG_TC_SAMPLES_4\r\n"); } else if (val==CR1_AVG_TC_SAMPLES_8) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_6_4, val); samples=8; LOG("Register containing\t\tsetNumSamplesAvg\t\twas programmed with the parameter\t\tCR1_AVG_TC_SAMPLES_8\r\n"); } else if (val==CR1_AVG_TC_SAMPLES_16) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_6_4, val); samples=16; LOG("Register containing\t\tsetNumSamplesAvg\t\twas programmed with the parameter\t\tCR1_AVG_TC_SAMPLES_16\r\n"); } else { LOG("Incorrect parameter selected for Control Register 1 (CR1) bits 6:4. Default value not changed.\r\nPlease see MAX31856.h for list of valid parameters. \r\n"); return_val=0; //returns a 0 to flag that the parameter wasn't programmed due to wrong parameter in function call } return return_val; } //Register:CR1 Bits: 3:0 //***************************************************************************** bool MAX31856::setThermocoupleType(uint8_t val) { if (val==CR1_TC_TYPE_B) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_3_0, val); voltage_mode=false; LOG("Register containing\t\tsetThermocoupleType\t\twas programmed with the parameter\t\tCR1_TC_TYPE_B\r\n"); } else if (val==CR1_TC_TYPE_E) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_3_0, val); voltage_mode=false; LOG("Register containing\t\tsetThermocoupleType\t\twas programmed with the parameter\t\tCR1_TC_TYPE_E\r\n"); } else if (val==CR1_TC_TYPE_J) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_3_0, val); voltage_mode=false; LOG("Register containing\t\tsetThermocoupleType\t\twas programmed with the parameter\t\tCR1_TC_TYPE_J\r\n"); } else if (val==CR1_TC_TYPE_K) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_3_0, val); voltage_mode=false; LOG("Register containing\t\tsetThermocoupleType\t\twas programmed with the parameter\t\tCR1_TC_TYPE_K\r\n"); } else if (val==CR1_TC_TYPE_N) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_3_0, val); voltage_mode=false; LOG("Register containing\t\tsetThermocoupleType\t\twas programmed with the parameter\t\tCR1_TC_TYPE_N\r\n"); } else if (val==CR1_TC_TYPE_R) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_3_0, val); voltage_mode=false; LOG("Register containing\t\tsetThermocoupleType\t\twas programmed with the parameter\t\tCR1_TC_TYPE_R\r\n"); } else if (val==CR1_TC_TYPE_S) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_3_0, val); voltage_mode=false; LOG("Register containing\t\tsetThermocoupleType\t\twas programmed with the parameter\t\tCR1_TC_TYPE_S\r\n"); } else if (val==CR1_TC_TYPE_T) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_3_0, val); voltage_mode=false; LOG("Register containing\t\tsetThermocoupleType\t\twas programmed with the parameter\t\tCR1_TC_TYPE_T\r\n"); } else if (val==CR1_TC_TYPE_VOLT_MODE_GAIN_8) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_3_0, val); voltage_mode=true; LOG("Register containing\t\tsetThermocoupleType\t\twas programmed with the parameter\t\tCR1_TC_TYPE_VOLT_MODE_GAIN_8\r\n"); } else if (val==CR1_TC_TYPE_VOLT_MODE_GAIN_32) { return_val=registerReadWriteByte(ADDRESS_CR1_READ, ADDRESS_CR1_WRITE, CR1_CLEAR_BITS_3_0, val); voltage_mode=true; LOG("Register containing\t\tsetThermocoupleType\t\twas programmed with the parameter\t\tCR1_TC_TYPE_VOLT_MODE_GAIN_32\r\n"); } else { LOG("Incorrect parameter selected for Control Register 1 (CR1) bits 3:0. Default value not changed.\r\nPlease see MAX31856.h for list of valid parameters. \r\n"); return_val=0; //returns a 0 to flag that the parameter wasn't programmed due to wrong parameter in function call } return return_val; } //Register:MASK Bits: 5:0 //***************************************************************************** bool MAX31856::setFaultMasks(uint8_t val, bool enable) { if(enable) val=0; if (val==MASK_CJ_FAULT_THRESHOLD_HIGH) { //Cold Junction High Threshold Fault Mask return_val=registerReadWriteByte(ADDRESS_MASK_READ, ADDRESS_MASK_WRITE, MASK_CLEAR_BITS_5, val); LOG("Register containing\t\tsetFaultMasks\t\twas programmed with the parameter\t\tMASK_CJ_FAULT_THRESHOLD_HIGH\r\n"); } else if (val==MASK_CJ_FAULT_THRESHOLD_LOW) { //Cold Junction Low Threshold Fault Mask return_val=registerReadWriteByte(ADDRESS_MASK_READ, ADDRESS_MASK_WRITE, MASK_CLEAR_BITS_4, val); LOG("Register containing\t\tsetFaultMasks\t\twas programmed with the parameter\t\tMASK_CJ_FAULT_THRESHOLD_LOW\r\n"); } else if (val==MASK_TC_FAULT_THRESHOLD_HIGH) { //Thermocouple High Threshold Fault Mask return_val=registerReadWriteByte(ADDRESS_MASK_READ, ADDRESS_MASK_WRITE, MASK_CLEAR_BITS_3, val); LOG("Register containing\t\tsetFaultMasks\t\twas programmed with the parameter\t\tMASK_TC_FAULT_THRESHOLD_HIGH\r\n"); } else if (val==MASK_TC_FAULT_THRESHOLD_LOW) { //Thermocouple Low Threshold Fault Mask return_val=registerReadWriteByte(ADDRESS_MASK_READ, ADDRESS_MASK_WRITE, MASK_CLEAR_BITS_2, val); LOG("Register containing\t\tsetFaultMasks\t\twas programmed with the parameter\t\tMASK_TC_FAULT_THRESHOLD_LOW\r\n"); } else if (val==MASK_OVER_UNDER_VOLT_FAULT) { //Over-Voltage/Under-Voltage Input Fault Mask return_val=registerReadWriteByte(ADDRESS_MASK_READ, ADDRESS_MASK_WRITE, MASK_CLEAR_BITS_1, val); LOG("Register containing\t\tsetFaultMasks\t\twas programmed with the parameter\t\tMASK_OVER_UNDER_VOLT_FAULT\r\n"); } else if (val==MASK_OPEN_CIRCUIT_FAULT) { //Thermocouple Open-Circuit Fault Mask return_val=registerReadWriteByte(ADDRESS_MASK_READ, ADDRESS_MASK_WRITE, MASK_CLEAR_BITS_0, val); LOG("Register containing\t\tsetFaultMasks\t\twas programmed with the parameter\t\tMASK_OPEN_CIRCUIT_FAULT\r\n"); } else { LOG("Incorrect parameter selected for Mask Register bits 5:0. Default value not changed.\r\nPlease see MAX31856.h for list of valid parameters. \r\n"); return_val=0; //returns a 0 to flag that the parameter wasn't programmed due to wrong parameter in function call } return return_val; } //Register:MASK Bits: 5:0 //****************************************************************************** bool MAX31856::setFaultThresholds(uint8_t val, float temperature) { if (val==MASK_CJ_FAULT_THRESHOLD_HIGH) { //Cold Junction High Threshold Fault Mask int8_t temperature_byte=temperature; return_val=registerWriteByte(ADDRESS_CJHF_WRITE, temperature_byte); } else if (val==MASK_CJ_FAULT_THRESHOLD_LOW) { //Cold Junction Low Threshold Fault Mask int8_t temperature_byte=temperature; return_val=registerWriteByte(ADDRESS_CJLF_WRITE, temperature_byte); } else if (val==MASK_TC_FAULT_THRESHOLD_HIGH) { //Thermocouple High Threshold Fault Mask int8_t temperature_byte[2]; int16_t temperature_multi_byte =temperature*4.0; //now split up the 16bit int into two bytes to program the registers with temperature_byte[0]=((uint8_t)((temperature_multi_byte)&(0xFF00) >> 8)); temperature_byte[1]=((uint8_t)((temperature_multi_byte)&(0x00FF))); return_val=registerWriteByte(ADDRESS_LTHFTH_WRITE, temperature_byte[0]); return_val=registerWriteByte(ADDRESS_LTHFTL_WRITE, temperature_byte[1]); } else if (val==MASK_TC_FAULT_THRESHOLD_LOW) { //Thermocouple LOW Threshold Fault Mask int8_t temperature_byte[2]; int16_t temperature_multi_byte =temperature*4.0; //now split up the 16bit int into two bytes to program the registers with temperature_byte[0]=((uint8_t)((temperature_multi_byte)&(0xFF00) >> 8)); temperature_byte[1]=((uint8_t)((temperature_multi_byte)&(0x00FF))); return_val=registerWriteByte(ADDRESS_LTHFTH_WRITE, temperature_byte[0]); return_val=registerWriteByte(ADDRESS_LTHFTL_WRITE, temperature_byte[1]); } else LOG("Please select correct threshold register to program with the correct value!\r\n"); return return_val; } //****************************************************************************** bool MAX31856::coldJunctionOffset(float temperature) { if (temperature > 7.9375 || temperature < -8.0) { LOG("Input value to offest the cold junction point is non valid. enter in value in range -8 to +7.9375\r\n"); return_val = 0; } int8_t temp_val=temperature*16.0f; //normalize the value to get rid of decimal and shorten it to size of register return_val=registerWriteByte(ADDRESS_CJTO_WRITE, temp_val); //write the byte to cold junction offset register return return_val; } //The following functions are for internal library use only //****************************************************************************** void MAX31856::spiEnable() { ncs=0; //Set CS low to start transmission (interrupts conversion) return; } //****************************************************************************** void MAX31856::spiDisable() { ncs=1; //Set CS high to stop transmission (restarts conversion) return; } //****************************************************************************** bool MAX31856::registerReadWriteByte(uint8_t read_address, uint8_t write_address, int clear_bits, uint8_t val) { uint8_t buf_read[2]; //Read the current contents of a register spiEnable(); for(int i=0; i<2; i++) { buf_read[i]=spi.write(read_address); } spiDisable(); //Modify contents pulled from the register buf_read[1]&=clear_bits; //Clear the contents of bits of parameter you are trying to clear for later or equal operation buf_read[1]|=val; //Bitwise OR the input parameter with cleaned buf_read[1] to create new byte val=buf_read[1]; //Write the updated byte to the register spiEnable(); buf_read[0]=spi.write(write_address); buf_read[1]=spi.write(val); spiDisable(); return 1; } //****************************************************************************** bool MAX31856::registerWriteByte(uint8_t write_address, uint8_t val) { //Write the updated byte to the register spiEnable(); spi.write(write_address); spi.write(val); spiDisable(); return true; } //****************************************************************************** uint8_t MAX31856::registerReadByte(uint8_t read_address) { uint8_t buf_read, buf_write=read_address; spiEnable(); buf_read=spi.write(buf_write); buf_read=spi.write(buf_write); spiDisable(); return buf_read; } //****************************************************************************** void MAX31856::calculateDelayTime() { uint32_t temp_int; if (conversion_mode==0 || thermocouple_conversion_count==0) { if (filter_mode==0) //60Hz temp_int=82+(samples-1)*33.33f; else //50Hz temp_int=98+(samples-1)*40.00f; } else { if (filter_mode==0) //60Hz temp_int=82+(samples-1)*16.67f; else //50Hz temp_int=98+(samples-1)*20.00f; } if (cold_junction_enabled==0) //cold junction is disabled enabling 25 millisecond faster conversion times temp_int=temp_int-25; conversion_time=1000*temp_int; //set private member conversion time to calculated minimum wait time in microseconds return; } //***************************************************************************** MAX31856::~MAX31856(void) { //empty block }