Maxim Integrated / MAX31723_Digital_Temperature_Sensor

C++ driver software code for Maxim Integrated MAX31723/MAX31722 device temperature sensor. The MAX31723 provides 9 to 12 bits of resolution.

Dependents:   MAX31723_Thermostat_Thermometer_Sensor

max31723.cpp@6:2e49aa7fa091, 2019-02-12 (annotated)

Committer:
phonemacro
Date:
Tue Feb 12 22:57:17 2019 +0000
Revision:
6:2e49aa7fa091
Parent:
5:8e70ec0923e2
Child:
8:e310e55a687b
Add Tlow, Thigh APIs

Who changed what in which revision?

UserRevisionLine numberNew contents of line
phonemacro 0:4a3d6ac5042d 1 /*******************************************************************************
phonemacro 0:4a3d6ac5042d 2 * Copyright (C) 2019 Maxim Integrated Products, Inc., All Rights Reserved.
phonemacro 0:4a3d6ac5042d 3 *
phonemacro 0:4a3d6ac5042d 4 * Permission is hereby granted, free of charge, to any person obtaining a
phonemacro 0:4a3d6ac5042d 5 * copy of this software and associated documentation files (the "Software"),
phonemacro 0:4a3d6ac5042d 6 * to deal in the Software without restriction, including without limitation
phonemacro 0:4a3d6ac5042d 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
phonemacro 0:4a3d6ac5042d 8 * and/or sell copies of the Software, and to permit persons to whom the
phonemacro 0:4a3d6ac5042d 9 * Software is furnished to do so, subject to the following conditions:
phonemacro 0:4a3d6ac5042d 10 *
phonemacro 0:4a3d6ac5042d 11 * The above copyright notice and this permission notice shall be included
phonemacro 0:4a3d6ac5042d 12 * in all copies or substantial portions of the Software.
phonemacro 0:4a3d6ac5042d 13 *
phonemacro 0:4a3d6ac5042d 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
phonemacro 0:4a3d6ac5042d 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
phonemacro 0:4a3d6ac5042d 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
phonemacro 0:4a3d6ac5042d 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
phonemacro 0:4a3d6ac5042d 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
phonemacro 0:4a3d6ac5042d 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
phonemacro 0:4a3d6ac5042d 20 * OTHER DEALINGS IN THE SOFTWARE.
phonemacro 0:4a3d6ac5042d 21 *
phonemacro 0:4a3d6ac5042d 22 * Except as contained in this notice, the name of Maxim Integrated
phonemacro 0:4a3d6ac5042d 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
phonemacro 0:4a3d6ac5042d 24 * Products, Inc. Branding Policy.
phonemacro 0:4a3d6ac5042d 25 *
phonemacro 0:4a3d6ac5042d 26 * The mere transfer of this software does not imply any licenses
phonemacro 0:4a3d6ac5042d 27 * of trade secrets, proprietary technology, copyrights, patents,
phonemacro 0:4a3d6ac5042d 28 * trademarks, maskwork rights, or any other form of intellectual
phonemacro 0:4a3d6ac5042d 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
phonemacro 0:4a3d6ac5042d 30 * ownership rights.
phonemacro 0:4a3d6ac5042d 31 *******************************************************************************
phonemacro 0:4a3d6ac5042d 32 */
phonemacro 0:4a3d6ac5042d 33 #include "max31723.h"
phonemacro 6:2e49aa7fa091 34 #include "USBSerial.h"
phonemacro 3:f39791139435 35 union max31723_raw_data {
phonemacro 3:f39791139435 36 struct {
phonemacro 3:f39791139435 37 uint8_t lsb;
phonemacro 3:f39791139435 38 uint8_t msb;
phonemacro 3:f39791139435 39 };
phonemacro 4:ac75d4d62471 40 uint16_t uwrd;
phonemacro 4:ac75d4d62471 41 int16_t swrd;
phonemacro 3:f39791139435 42 };
phonemacro 0:4a3d6ac5042d 43
phonemacro 0:4a3d6ac5042d 44 MAX31723::MAX31723(SPI &spi, DigitalOut &ce_pin) : m_spi(spi), m_chip_enable(ce_pin)
phonemacro 0:4a3d6ac5042d 45 {
phonemacro 0:4a3d6ac5042d 46 m_chip_enable = 0;
phonemacro 0:4a3d6ac5042d 47 }
phonemacro 0:4a3d6ac5042d 48
phonemacro 6:2e49aa7fa091 49
phonemacro 6:2e49aa7fa091 50 int MAX31723::read_reg(uint8_t &val, uint8_t reg)
phonemacro 6:2e49aa7fa091 51 {
phonemacro 6:2e49aa7fa091 52 if (reg <= MAX31723_REG_MAX) {
phonemacro 6:2e49aa7fa091 53 m_chip_enable = 1;
phonemacro 6:2e49aa7fa091 54 m_spi.write(reg);
phonemacro 6:2e49aa7fa091 55 val = m_spi.write(0);
phonemacro 6:2e49aa7fa091 56 m_chip_enable = 0;
phonemacro 6:2e49aa7fa091 57 return MAX31723_NO_ERROR;
phonemacro 6:2e49aa7fa091 58 } else {
phonemacro 6:2e49aa7fa091 59 printf("Input read_reg is invalid, 0x%02X \r\n", reg);
phonemacro 6:2e49aa7fa091 60 return MAX31723_ERROR;
phonemacro 6:2e49aa7fa091 61 }
phonemacro 6:2e49aa7fa091 62 }
phonemacro 6:2e49aa7fa091 63
phonemacro 6:2e49aa7fa091 64 uint8_t MAX31723::read_cfg()
phonemacro 6:2e49aa7fa091 65 {
phonemacro 6:2e49aa7fa091 66 uint8_t cfg;
phonemacro 6:2e49aa7fa091 67 read_reg(cfg, MAX31723_REG_CFG);
phonemacro 6:2e49aa7fa091 68 return cfg;
phonemacro 6:2e49aa7fa091 69 }
phonemacro 6:2e49aa7fa091 70
phonemacro 6:2e49aa7fa091 71 float MAX31723::read_reg_as_temperature(uint8_t reg)
phonemacro 6:2e49aa7fa091 72 {
phonemacro 6:2e49aa7fa091 73 max31723_raw_data raw;
phonemacro 6:2e49aa7fa091 74 float temperature;
phonemacro 6:2e49aa7fa091 75 if (reg >= MAX31723_REG_TEMP_LSB && reg <= MAX31723_REG_MAX) {
phonemacro 6:2e49aa7fa091 76 read_reg(raw.lsb, reg);
phonemacro 6:2e49aa7fa091 77 read_reg(raw.msb, reg+1);
phonemacro 6:2e49aa7fa091 78 temperature = raw.swrd * MAX31723_CF_LSB;
phonemacro 6:2e49aa7fa091 79 return temperature;
phonemacro 6:2e49aa7fa091 80 } else {
phonemacro 6:2e49aa7fa091 81 printf("Input read_registers_as_temperature is invalid, %d r\n",
phonemacro 6:2e49aa7fa091 82 reg);
phonemacro 6:2e49aa7fa091 83 return 0;
phonemacro 6:2e49aa7fa091 84 }
phonemacro 6:2e49aa7fa091 85 }
phonemacro 6:2e49aa7fa091 86
phonemacro 6:2e49aa7fa091 87 float MAX31723::read_temperature(void)
phonemacro 6:2e49aa7fa091 88 {
phonemacro 6:2e49aa7fa091 89 return read_reg_as_temperature(MAX31723_REG_TEMP_LSB);
phonemacro 6:2e49aa7fa091 90 }
phonemacro 6:2e49aa7fa091 91
phonemacro 6:2e49aa7fa091 92 float MAX31723::read_trip_low(void)
phonemacro 6:2e49aa7fa091 93 {
phonemacro 6:2e49aa7fa091 94 return read_reg_as_temperature(MAX31723_REG_TRIP_LO_LSB);
phonemacro 6:2e49aa7fa091 95 }
phonemacro 6:2e49aa7fa091 96
phonemacro 6:2e49aa7fa091 97 float MAX31723::read_trip_high(void)
phonemacro 6:2e49aa7fa091 98 {
phonemacro 6:2e49aa7fa091 99 return read_reg_as_temperature(MAX31723_REG_TRIP_HI_LSB);
phonemacro 6:2e49aa7fa091 100 }
phonemacro 6:2e49aa7fa091 101
phonemacro 0:4a3d6ac5042d 102 int MAX31723::write_reg(uint8_t val, uint8_t reg)
phonemacro 0:4a3d6ac5042d 103 {
phonemacro 4:ac75d4d62471 104 if (reg == (MAX31723_REG_CFG | MAX31723_WRITE_MASK) ||
phonemacro 4:ac75d4d62471 105 (reg >= (MAX31723_REG_TRIP_HI_LSB | MAX31723_WRITE_MASK) &&
phonemacro 4:ac75d4d62471 106 reg <= (MAX31723_REG_MAX | MAX31723_WRITE_MASK)) ) {
phonemacro 4:ac75d4d62471 107 m_chip_enable = 1;
phonemacro 4:ac75d4d62471 108 m_spi.write(reg);
phonemacro 4:ac75d4d62471 109 m_spi.write(val);
phonemacro 4:ac75d4d62471 110 m_chip_enable = 0;
phonemacro 4:ac75d4d62471 111 return MAX31723_NO_ERROR;
phonemacro 4:ac75d4d62471 112 } else {
phonemacro 4:ac75d4d62471 113 printf("Input write_reg is invalid, 0x%02X \r\n", reg);
phonemacro 4:ac75d4d62471 114 return MAX31723_ERROR;
phonemacro 4:ac75d4d62471 115 }
phonemacro 0:4a3d6ac5042d 116 }
phonemacro 0:4a3d6ac5042d 117
phonemacro 6:2e49aa7fa091 118 int MAX31723::write_cfg(uint8_t val)
phonemacro 0:4a3d6ac5042d 119 {
phonemacro 4:ac75d4d62471 120 m_chip_enable = 1;
phonemacro 6:2e49aa7fa091 121 m_spi.write(MAX31723_REG_CFG );
phonemacro 6:2e49aa7fa091 122 m_spi.write(val);
phonemacro 4:ac75d4d62471 123 m_chip_enable = 0;
phonemacro 4:ac75d4d62471 124 return MAX31723_NO_ERROR;
phonemacro 6:2e49aa7fa091 125 }
phonemacro 6:2e49aa7fa091 126
phonemacro 6:2e49aa7fa091 127
phonemacro 6:2e49aa7fa091 128 int MAX31723::write_trip_low(float temperature)
phonemacro 6:2e49aa7fa091 129 {
phonemacro 6:2e49aa7fa091 130 int ret;
phonemacro 6:2e49aa7fa091 131 max31723_raw_data raw;
phonemacro 6:2e49aa7fa091 132 temperature /= MAX31723_CF_LSB;
phonemacro 6:2e49aa7fa091 133 raw.swrd = int16_t(temperature);
phonemacro 6:2e49aa7fa091 134 ret = write_reg(raw.lsb, MAX31723_WRITE_MASK | MAX31723_REG_TRIP_LO_LSB);
phonemacro 6:2e49aa7fa091 135 wait(.015);
phonemacro 6:2e49aa7fa091 136 ret = write_reg(raw.msb, MAX31723_WRITE_MASK | MAX31723_REG_TRIP_LO_MSB);
phonemacro 6:2e49aa7fa091 137 wait(.015);
phonemacro 6:2e49aa7fa091 138 return ret;
phonemacro 0:4a3d6ac5042d 139 }
phonemacro 0:4a3d6ac5042d 140
phonemacro 6:2e49aa7fa091 141 int MAX31723::write_trip_high(float temperature)
phonemacro 6:2e49aa7fa091 142 {
phonemacro 6:2e49aa7fa091 143 int ret;
phonemacro 6:2e49aa7fa091 144 max31723_raw_data raw;
phonemacro 6:2e49aa7fa091 145 temperature /= MAX31723_CF_LSB;
phonemacro 6:2e49aa7fa091 146 raw.swrd = int16_t(temperature);
phonemacro 6:2e49aa7fa091 147 ret = write_reg(raw.lsb, MAX31723_WRITE_MASK | MAX31723_REG_TRIP_HI_LSB);
phonemacro 6:2e49aa7fa091 148 wait(.015);
phonemacro 6:2e49aa7fa091 149 ret = write_reg(raw.msb, MAX31723_WRITE_MASK | MAX31723_REG_TRIP_HI_MSB);
phonemacro 6:2e49aa7fa091 150 wait(.015);
phonemacro 6:2e49aa7fa091 151 return ret;
phonemacro 6:2e49aa7fa091 152 }
phonemacro 6:2e49aa7fa091 153
phonemacro 6:2e49aa7fa091 154
phonemacro 3:f39791139435 155 int MAX31723::perform_one_shot(uint8_t resolution, uint8_t interrupt_mode)
phonemacro 0:4a3d6ac5042d 156 {
phonemacro 2:7a20e65da621 157 if (resolution <= MAX31723_CFG_RESOLUTION_12BIT) {
phonemacro 2:7a20e65da621 158 write_reg(0, MAX31723_REG_CFG | MAX31723_WRITE_MASK);
phonemacro 3:f39791139435 159 write_reg(interrupt_mode | MAX31723_CFG_1SHOT |
phonemacro 2:7a20e65da621 160 resolution | MAX31723_CFG_STANDBY,
phonemacro 0:4a3d6ac5042d 161 MAX31723_REG_CFG | MAX31723_WRITE_MASK);
phonemacro 2:7a20e65da621 162 } else
phonemacro 0:4a3d6ac5042d 163 return MAX31723_ERROR;
phonemacro 0:4a3d6ac5042d 164 return MAX31723_NO_ERROR;
phonemacro 0:4a3d6ac5042d 165 }
phonemacro 0:4a3d6ac5042d 166
phonemacro 3:f39791139435 167 int MAX31723::perform_one_shot_int(uint8_t resolution)
phonemacro 0:4a3d6ac5042d 168 {
phonemacro 3:f39791139435 169 int ret;
phonemacro 3:f39791139435 170 ret = perform_one_shot(resolution, MAX31723_CFG_TM_MODE_INTERRUPT);
phonemacro 3:f39791139435 171 return ret;
phonemacro 3:f39791139435 172 }
phonemacro 3:f39791139435 173
phonemacro 3:f39791139435 174 int MAX31723::perform_one_shot_comparator(uint8_t resolution)
phonemacro 3:f39791139435 175 {
phonemacro 3:f39791139435 176 int ret;
phonemacro 3:f39791139435 177 ret = perform_one_shot(resolution, 0);
phonemacro 3:f39791139435 178 return ret;
phonemacro 0:4a3d6ac5042d 179 }
phonemacro 0:4a3d6ac5042d 180
phonemacro 0:4a3d6ac5042d 181
phonemacro 0:4a3d6ac5042d 182 float MAX31723::celsius_to_fahrenheit(float temp_c)
phonemacro 0:4a3d6ac5042d 183 {
phonemacro 0:4a3d6ac5042d 184 float temp_f;
phonemacro 0:4a3d6ac5042d 185 temp_f = ((temp_c * 9)/5) + 32;
phonemacro 0:4a3d6ac5042d 186 return temp_f;
phonemacro 0:4a3d6ac5042d 187 }
phonemacro 0:4a3d6ac5042d 188
phonemacro 0:4a3d6ac5042d 189 MAX31723::~MAX31723(void)
phonemacro 0:4a3d6ac5042d 190 {
phonemacro 0:4a3d6ac5042d 191 //empty block
phonemacro 0:4a3d6ac5042d 192 }
phonemacro 0:4a3d6ac5042d 193