Maxim Integrated / MAX30205_Clinical_Temperature_Sensor

Maxim Integrated MAX30205 C, C++ source code driver software: MAX30205 is accurate to +-0.1°C over the range of 37.0°C to 39.0°C. One-shot, shutdown modes are available for reduced power usage. Thermostat thresholds allow for temperature hysteresis or for alarm settings. The MAX30205 is available in a compact 3x3 mm, 8-pin TDFN package. Operating supply voltage range is 2.7V to 3.3V. Typical applications are for clinical digital thermometers, thermostats with hysteresis, and temperature alarms.

Dependents:   MAX30205_Human_Body_Temperature_Sensor

max30205_cpp.cpp@10:9c5dc1393570, 2019-04-17 (annotated)

Committer:
phonemacro
Date:
Wed Apr 17 21:13:54 2019 +0000
Revision:
10:9c5dc1393570
Parent:
9:d98e4a80a866 
Updated comments

Who changed what in which revision?

UserRevisionLine numberNew contents of line
phonemacro 9:d98e4a80a866 1 /*******************************************************************************
phonemacro 9:d98e4a80a866 2 * Copyright (C) 2019 Maxim Integrated Products, Inc., All Rights Reserved.
phonemacro 9:d98e4a80a866 3 *
phonemacro 9:d98e4a80a866 4 * Permission is hereby granted, free of charge, to any person obtaining a
phonemacro 9:d98e4a80a866 5 * copy of this software and associated documentation files (the "Software"),
phonemacro 9:d98e4a80a866 6 * to deal in the Software without restriction, including without limitation
phonemacro 9:d98e4a80a866 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
phonemacro 9:d98e4a80a866 8 * and/or sell copies of the Software, and to permit persons to whom the
phonemacro 9:d98e4a80a866 9 * Software is furnished to do so, subject to the following conditions:
phonemacro 9:d98e4a80a866 10 *
phonemacro 9:d98e4a80a866 11 * The above copyright notice and this permission notice shall be included
phonemacro 9:d98e4a80a866 12 * in all copies or substantial portions of the Software.
phonemacro 9:d98e4a80a866 13 *
phonemacro 9:d98e4a80a866 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
phonemacro 9:d98e4a80a866 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
phonemacro 9:d98e4a80a866 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
phonemacro 9:d98e4a80a866 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
phonemacro 9:d98e4a80a866 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
phonemacro 9:d98e4a80a866 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
phonemacro 9:d98e4a80a866 20 * OTHER DEALINGS IN THE SOFTWARE.
phonemacro 9:d98e4a80a866 21 *
phonemacro 9:d98e4a80a866 22 * Except as contained in this notice, the name of Maxim Integrated
phonemacro 9:d98e4a80a866 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
phonemacro 9:d98e4a80a866 24 * Products, Inc. Branding Policy.
phonemacro 9:d98e4a80a866 25 *
phonemacro 9:d98e4a80a866 26 * The mere transfer of this software does not imply any licenses
phonemacro 9:d98e4a80a866 27 * of trade secrets, proprietary technology, copyrights, patents,
phonemacro 9:d98e4a80a866 28 * trademarks, maskwork rights, or any other form of intellectual
phonemacro 9:d98e4a80a866 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
phonemacro 9:d98e4a80a866 30 * ownership rights.
phonemacro 9:d98e4a80a866 31 *******************************************************************************
phonemacro 9:d98e4a80a866 32 */
phonemacro 9:d98e4a80a866 33 #include "max30205.h"
phonemacro 9:d98e4a80a866 34 #include "max30205_cpp.h"
phonemacro 9:d98e4a80a866 35 #include "mbed.h"
phonemacro 9:d98e4a80a866 36 // #include "USBSerial.h"
phonemacro 9:d98e4a80a866 37
phonemacro 9:d98e4a80a866 38 /******************************************************************************
phonemacro 9:d98e4a80a866 39 * C++ version for MAX30205 driver *
phonemacro 9:d98e4a80a866 40 ******************************************************************************
phonemacro 9:d98e4a80a866 41 */
phonemacro 9:d98e4a80a866 42
phonemacro 9:d98e4a80a866 43 /******************************************************************************/
phonemacro 9:d98e4a80a866 44 MAX30205::MAX30205(I2C &i2c_bus, uint8_t slave_address):
phonemacro 9:d98e4a80a866 45 m_i2c(i2c_bus),
phonemacro 9:d98e4a80a866 46 m_write_address(slave_address <<1),
phonemacro 9:d98e4a80a866 47 m_read_address ((slave_address << 1) | 1)
phonemacro 9:d98e4a80a866 48 {
phonemacro 9:d98e4a80a866 49 max30205_extended_format = 0;
phonemacro 9:d98e4a80a866 50 }
phonemacro 9:d98e4a80a866 51
phonemacro 9:d98e4a80a866 52 /******************************************************************************/
phonemacro 9:d98e4a80a866 53 MAX30205::~MAX30205(void)
phonemacro 9:d98e4a80a866 54 {
phonemacro 9:d98e4a80a866 55 /** empty block */
phonemacro 9:d98e4a80a866 56 }
phonemacro 9:d98e4a80a866 57
phonemacro 9:d98e4a80a866 58 /******************************************************************************/
phonemacro 9:d98e4a80a866 59 int MAX30205::read_cfg_reg(uint8_t *value)
phonemacro 9:d98e4a80a866 60 {
phonemacro 9:d98e4a80a866 61 int32_t ret;
phonemacro 9:d98e4a80a866 62 char data[1] = {0};
phonemacro 9:d98e4a80a866 63 char reg = MAX30205_REG_CONFIGURATION;
phonemacro 9:d98e4a80a866 64
phonemacro 9:d98e4a80a866 65 /* write to the Register Select, true is for repeated start */
phonemacro 9:d98e4a80a866 66 ret = m_i2c.write(m_write_address, &reg, 1, true);
phonemacro 9:d98e4a80a866 67 if (ret == 0) {
phonemacro 9:d98e4a80a866 68 ret = m_i2c.read(m_read_address, data, 1, false);
phonemacro 9:d98e4a80a866 69 if (ret == 0) {
phonemacro 9:d98e4a80a866 70 *value = data[0];
phonemacro 9:d98e4a80a866 71 return MAX30205_NO_ERROR;
phonemacro 9:d98e4a80a866 72 } else {
phonemacro 9:d98e4a80a866 73 printf(
phonemacro 9:d98e4a80a866 74 "%s: failed to read data: ret: %d\r\n", __func__, ret);
phonemacro 9:d98e4a80a866 75 }
phonemacro 9:d98e4a80a866 76 } else {
phonemacro 9:d98e4a80a866 77 printf("%s: failed to write to Register Select: ret: %d\r\n",
phonemacro 9:d98e4a80a866 78 __func__, ret);
phonemacro 9:d98e4a80a866 79 }
phonemacro 9:d98e4a80a866 80 return MAX30205_ERROR;
phonemacro 9:d98e4a80a866 81 }
phonemacro 9:d98e4a80a866 82
phonemacro 9:d98e4a80a866 83 /******************************************************************************/
phonemacro 9:d98e4a80a866 84 int MAX30205::read_reg16(int16_t *value, char reg)
phonemacro 9:d98e4a80a866 85 {
phonemacro 9:d98e4a80a866 86 int32_t ret;
phonemacro 9:d98e4a80a866 87 char data[2] = {0, 0};
phonemacro 9:d98e4a80a866 88 max30205_raw_data tmp;
phonemacro 9:d98e4a80a866 89
phonemacro 9:d98e4a80a866 90 if (reg == MAX30205_REG_TEMPERATURE ||
phonemacro 9:d98e4a80a866 91 reg == MAX30205_REG_THYST_LOW_TRIP || reg == MAX30205_REG_TOS_HIGH_TRIP) {
phonemacro 9:d98e4a80a866 92 /* write to the Register Select, true is for repeated start */
phonemacro 9:d98e4a80a866 93 ret = m_i2c.write(m_write_address, &reg, 1, true);
phonemacro 9:d98e4a80a866 94 /* read the two bytes of data */
phonemacro 9:d98e4a80a866 95 if (ret == 0) {
phonemacro 9:d98e4a80a866 96 ret = m_i2c.read(m_read_address, data, 2, false);
phonemacro 9:d98e4a80a866 97 if (ret == 0) {
phonemacro 9:d98e4a80a866 98 tmp.msb = data[0];
phonemacro 9:d98e4a80a866 99 tmp.lsb = data[1];
phonemacro 9:d98e4a80a866 100 *value = tmp.swrd;
phonemacro 9:d98e4a80a866 101 return MAX30205_NO_ERROR;
phonemacro 9:d98e4a80a866 102 } else {
phonemacro 9:d98e4a80a866 103 printf(
phonemacro 9:d98e4a80a866 104 "%s: failed to read data: ret: %d\r\n", __func__, ret);
phonemacro 9:d98e4a80a866 105 }
phonemacro 9:d98e4a80a866 106 } else {
phonemacro 9:d98e4a80a866 107 printf("%s: failed to write to Register Select: ret: %d\r\n",
phonemacro 9:d98e4a80a866 108 __func__, ret);
phonemacro 9:d98e4a80a866 109 }
phonemacro 9:d98e4a80a866 110 } else {
phonemacro 9:d98e4a80a866 111 printf("%s: register address is not correct: register: %d\r\n",
phonemacro 9:d98e4a80a866 112 __func__, reg);
phonemacro 9:d98e4a80a866 113 }
phonemacro 9:d98e4a80a866 114 return MAX30205_ERROR;
phonemacro 9:d98e4a80a866 115 }
phonemacro 9:d98e4a80a866 116
phonemacro 9:d98e4a80a866 117 /******************************************************************************/
phonemacro 9:d98e4a80a866 118 float MAX30205::read_reg_as_temperature(uint8_t reg)
phonemacro 9:d98e4a80a866 119 {
phonemacro 9:d98e4a80a866 120 max30205_raw_data tmp;
phonemacro 9:d98e4a80a866 121 float temperature;
phonemacro 9:d98e4a80a866 122 if (reg == MAX30205_REG_TEMPERATURE ||
phonemacro 9:d98e4a80a866 123 reg == MAX30205_REG_THYST_LOW_TRIP || reg == MAX30205_REG_TOS_HIGH_TRIP) {
phonemacro 9:d98e4a80a866 124 read_reg16(&tmp.swrd, reg);
phonemacro 9:d98e4a80a866 125 temperature = (float)tmp.swrd; /* values are 2's complement */
phonemacro 9:d98e4a80a866 126 temperature *= MAX30205_CF_LSB;
phonemacro 9:d98e4a80a866 127 if (reg == MAX30205_REG_TEMPERATURE && max30205_extended_format)
phonemacro 9:d98e4a80a866 128 temperature += MAX30205_EXTENDED_FORMAT_OFFSET;
phonemacro 9:d98e4a80a866 129
phonemacro 9:d98e4a80a866 130 return temperature;
phonemacro 9:d98e4a80a866 131 } else {
phonemacro 9:d98e4a80a866 132 printf("%s: register is invalid, %d r\n", __func__, reg);
phonemacro 9:d98e4a80a866 133 return 0;
phonemacro 9:d98e4a80a866 134 }
phonemacro 9:d98e4a80a866 135 }
phonemacro 9:d98e4a80a866 136
phonemacro 9:d98e4a80a866 137 /******************************************************************************/
phonemacro 9:d98e4a80a866 138 int MAX30205::write_reg16(int16_t value, char reg)
phonemacro 9:d98e4a80a866 139 {
phonemacro 9:d98e4a80a866 140 int32_t ret;
phonemacro 9:d98e4a80a866 141 char cmd[3];
phonemacro 9:d98e4a80a866 142 max30205_raw_data tmp;
phonemacro 9:d98e4a80a866 143
phonemacro 9:d98e4a80a866 144 if (reg >= MAX30205_REG_THYST_LOW_TRIP && reg <= MAX30205_REG_MAX) {
phonemacro 9:d98e4a80a866 145 cmd[0] = reg;
phonemacro 9:d98e4a80a866 146 tmp.swrd = value;
phonemacro 9:d98e4a80a866 147 cmd[1] = tmp.msb;
phonemacro 9:d98e4a80a866 148 cmd[2] = tmp.lsb;
phonemacro 9:d98e4a80a866 149 ret = m_i2c.write(m_write_address, cmd, 3, false);
phonemacro 9:d98e4a80a866 150 if (ret == 0) {
phonemacro 9:d98e4a80a866 151 return MAX30205_NO_ERROR;
phonemacro 9:d98e4a80a866 152 } else {
phonemacro 9:d98e4a80a866 153 printf("%s: I2C write error %d\r\n",__func__, ret);
phonemacro 9:d98e4a80a866 154 return MAX30205_ERROR;
phonemacro 9:d98e4a80a866 155 }
phonemacro 9:d98e4a80a866 156 } else {
phonemacro 9:d98e4a80a866 157 printf("%s: register value invalid %x\r\n",__func__, reg);
phonemacro 9:d98e4a80a866 158 return MAX30205_ERROR;
phonemacro 9:d98e4a80a866 159 }
phonemacro 9:d98e4a80a866 160 }
phonemacro 9:d98e4a80a866 161
phonemacro 9:d98e4a80a866 162
phonemacro 9:d98e4a80a866 163 /******************************************************************************/
phonemacro 9:d98e4a80a866 164 int MAX30205::write_cfg_reg(uint8_t cfg)
phonemacro 9:d98e4a80a866 165 {
phonemacro 9:d98e4a80a866 166 int32_t ret;
phonemacro 9:d98e4a80a866 167 char cmd[2];
phonemacro 9:d98e4a80a866 168
phonemacro 9:d98e4a80a866 169 cmd[0] = MAX30205_REG_CONFIGURATION;
phonemacro 9:d98e4a80a866 170 cmd[1] = cfg;
phonemacro 9:d98e4a80a866 171 ret = m_i2c.write(m_write_address, cmd, 2, false);
phonemacro 9:d98e4a80a866 172 if (ret == 0) {
phonemacro 9:d98e4a80a866 173 max30205_extended_format = 0;
phonemacro 9:d98e4a80a866 174 if (cfg & MAX30205_CFG_EXTENDED_FORMAT)
phonemacro 9:d98e4a80a866 175 max30205_extended_format = 1;
phonemacro 9:d98e4a80a866 176
phonemacro 9:d98e4a80a866 177 return MAX30205_NO_ERROR;
phonemacro 9:d98e4a80a866 178 } else {
phonemacro 9:d98e4a80a866 179 printf("%s: I2C write error %d\r\n",__func__, ret);
phonemacro 9:d98e4a80a866 180 return MAX30205_ERROR;
phonemacro 9:d98e4a80a866 181 }
phonemacro 9:d98e4a80a866 182 }
phonemacro 9:d98e4a80a866 183
phonemacro 9:d98e4a80a866 184 /******************************************************************************/
phonemacro 9:d98e4a80a866 185 int MAX30205::write_trip_low_thyst(float temperature)
phonemacro 9:d98e4a80a866 186 {
phonemacro 9:d98e4a80a866 187 max30205_raw_data raw;
phonemacro 9:d98e4a80a866 188 temperature /= MAX30205_CF_LSB;
phonemacro 9:d98e4a80a866 189 raw.swrd = int16_t(temperature);
phonemacro 9:d98e4a80a866 190 return write_reg16(raw.swrd, MAX30205_REG_THYST_LOW_TRIP);
phonemacro 9:d98e4a80a866 191 }
phonemacro 9:d98e4a80a866 192
phonemacro 9:d98e4a80a866 193 /******************************************************************************/
phonemacro 9:d98e4a80a866 194 int MAX30205::write_trip_high_tos(float temperature)
phonemacro 9:d98e4a80a866 195 {
phonemacro 9:d98e4a80a866 196 max30205_raw_data raw;
phonemacro 9:d98e4a80a866 197 temperature /= MAX30205_CF_LSB;
phonemacro 9:d98e4a80a866 198 raw.swrd = int16_t(temperature);
phonemacro 9:d98e4a80a866 199 return write_reg16(raw.uwrd, MAX30205_REG_TOS_HIGH_TRIP);
phonemacro 9:d98e4a80a866 200 }
phonemacro 9:d98e4a80a866 201
phonemacro 9:d98e4a80a866 202 /******************************************************************************/
phonemacro 9:d98e4a80a866 203 float MAX30205::celsius_to_fahrenheit(float temp_c)
phonemacro 9:d98e4a80a866 204 {
phonemacro 9:d98e4a80a866 205 float temp_f;
phonemacro 9:d98e4a80a866 206 temp_f = ((temp_c * 9)/5) + 32;
phonemacro 9:d98e4a80a866 207 return temp_f;
phonemacro 9:d98e4a80a866 208 }