Maxim Integrated / Mbed 2 deprecated DeepCover Embedded Security in IoT

MAXREFDES143#: DeepCover Embedded Security in IoT Authenticated Sensing & Notification

Dependencies:   MaximInterface mbed

The MAXREFDES143# is an Internet of Things (IoT) embedded security reference design, built to protect an industrial sensing node by means of authentication and notification to a web server. The hardware includes a peripheral module representing a protected sensor node monitoring operating temperature and remaining life of a filter (simulated through ambient light sensing) and an mbed shield representing a controller node responsible for monitoring one or more sensor nodes. The design is hierarchical with each controller node communicating data from connected sensor nodes to a web server that maintains a centralized log and dispatches notifications as necessary. The mbed shield contains a Wi-Fi module, a DS2465 coprocessor with 1-Wire® master function, an LCD, LEDs, and pushbuttons. The protected sensor node contains a DS28E15 authenticator, a DS7505 temperature sensor, and a MAX44009 light sensor. The mbed shield communicates to a web server by the onboard Wi-Fi module and to the protected sensor node with I2C and 1-Wire. The MAXREFDES143# is equipped with a standard shield connector for immediate testing using an mbed board such as the MAX32600MBED#. The simplicity of this design enables rapid integration into any star-topology IoT network requiring the heightened security with low overhead provided by the SHA-256 symmetric-key algorithm.

More information about the MAXREFDES143# is available on the Maxim Integrated website.

DS7505.cpp@6:b6bafd0a7013, 2016-05-12 (annotated)

Committer:
IanBenzMaxim
Date:
Thu May 12 14:40:14 2016 -0500
Revision:
6:b6bafd0a7013
Parent:
1:e1c7c1c636af
Child:
21:b43e2f7bea6f
Updated following downstream restructuring in OneWire library.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
IanBenzMaxim 1:e1c7c1c636af 1 /*******************************************************************************
IanBenzMaxim 1:e1c7c1c636af 2 * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
IanBenzMaxim 1:e1c7c1c636af 3 *
IanBenzMaxim 1:e1c7c1c636af 4 * Permission is hereby granted, free of charge, to any person obtaining a
IanBenzMaxim 1:e1c7c1c636af 5 * copy of this software and associated documentation files (the "Software"),
IanBenzMaxim 1:e1c7c1c636af 6 * to deal in the Software without restriction, including without limitation
IanBenzMaxim 1:e1c7c1c636af 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
IanBenzMaxim 1:e1c7c1c636af 8 * and/or sell copies of the Software, and to permit persons to whom the
IanBenzMaxim 1:e1c7c1c636af 9 * Software is furnished to do so, subject to the following conditions:
IanBenzMaxim 1:e1c7c1c636af 10 *
IanBenzMaxim 1:e1c7c1c636af 11 * The above copyright notice and this permission notice shall be included
IanBenzMaxim 1:e1c7c1c636af 12 * in all copies or substantial portions of the Software.
IanBenzMaxim 1:e1c7c1c636af 13 *
IanBenzMaxim 1:e1c7c1c636af 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
IanBenzMaxim 1:e1c7c1c636af 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
IanBenzMaxim 1:e1c7c1c636af 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IanBenzMaxim 1:e1c7c1c636af 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
IanBenzMaxim 1:e1c7c1c636af 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
IanBenzMaxim 1:e1c7c1c636af 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
IanBenzMaxim 1:e1c7c1c636af 20 * OTHER DEALINGS IN THE SOFTWARE.
IanBenzMaxim 1:e1c7c1c636af 21 *
IanBenzMaxim 1:e1c7c1c636af 22 * Except as contained in this notice, the name of Maxim Integrated
IanBenzMaxim 1:e1c7c1c636af 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
IanBenzMaxim 1:e1c7c1c636af 24 * Products, Inc. Branding Policy.
IanBenzMaxim 1:e1c7c1c636af 25 *
IanBenzMaxim 1:e1c7c1c636af 26 * The mere transfer of this software does not imply any licenses
IanBenzMaxim 1:e1c7c1c636af 27 * of trade secrets, proprietary technology, copyrights, patents,
IanBenzMaxim 1:e1c7c1c636af 28 * trademarks, maskwork rights, or any other form of intellectual
IanBenzMaxim 1:e1c7c1c636af 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
IanBenzMaxim 1:e1c7c1c636af 30 * ownership rights.
IanBenzMaxim 1:e1c7c1c636af 31 *******************************************************************************
IanBenzMaxim 1:e1c7c1c636af 32 */
IanBenzMaxim 1:e1c7c1c636af 33
IanBenzMaxim 1:e1c7c1c636af 34 #include "DS7505.hpp"
IanBenzMaxim 6:b6bafd0a7013 35 #include "I2C.h"
IanBenzMaxim 6:b6bafd0a7013 36 #include "wait_api.h"
IanBenzMaxim 1:e1c7c1c636af 37
IanBenzMaxim 1:e1c7c1c636af 38 #define I2C_WRITE 0
IanBenzMaxim 1:e1c7c1c636af 39 #define I2C_READ 1
IanBenzMaxim 1:e1c7c1c636af 40
IanBenzMaxim 1:e1c7c1c636af 41 static const int I2C_WRITE_OK = 0;
IanBenzMaxim 1:e1c7c1c636af 42 static const uint8_t DS7505_Config_SD_Bit = 0x01; // Enable shutdown mode
IanBenzMaxim 1:e1c7c1c636af 43
IanBenzMaxim 6:b6bafd0a7013 44 DS7505::DS7505(mbed::I2C & I2C_interface, uint8_t I2C_address)
IanBenzMaxim 1:e1c7c1c636af 45 : m_current_config(Config_9b_Res, true), m_I2C_interface(I2C_interface), m_I2C_address(I2C_address)
IanBenzMaxim 1:e1c7c1c636af 46 {
IanBenzMaxim 1:e1c7c1c636af 47
IanBenzMaxim 1:e1c7c1c636af 48 }
IanBenzMaxim 1:e1c7c1c636af 49
IanBenzMaxim 1:e1c7c1c636af 50 uint8_t DS7505::get_measure_delay_ms(Config_Resolution resolution)
IanBenzMaxim 1:e1c7c1c636af 51 {
IanBenzMaxim 1:e1c7c1c636af 52 uint8_t measure_delay_ms;
IanBenzMaxim 1:e1c7c1c636af 53
IanBenzMaxim 1:e1c7c1c636af 54 switch (resolution)
IanBenzMaxim 1:e1c7c1c636af 55 {
IanBenzMaxim 1:e1c7c1c636af 56 case Config_9b_Res:
IanBenzMaxim 1:e1c7c1c636af 57 measure_delay_ms = 25;
IanBenzMaxim 1:e1c7c1c636af 58 break;
IanBenzMaxim 1:e1c7c1c636af 59 case Config_10b_Res:
IanBenzMaxim 1:e1c7c1c636af 60 measure_delay_ms = 50;
IanBenzMaxim 1:e1c7c1c636af 61 break;
IanBenzMaxim 1:e1c7c1c636af 62 case Config_11b_Res:
IanBenzMaxim 1:e1c7c1c636af 63 measure_delay_ms = 100;
IanBenzMaxim 1:e1c7c1c636af 64 break;
IanBenzMaxim 1:e1c7c1c636af 65 case Config_12b_Res:
IanBenzMaxim 1:e1c7c1c636af 66 measure_delay_ms = 200;
IanBenzMaxim 1:e1c7c1c636af 67 break;
IanBenzMaxim 1:e1c7c1c636af 68 default:
IanBenzMaxim 1:e1c7c1c636af 69 measure_delay_ms = 0;
IanBenzMaxim 1:e1c7c1c636af 70 break;
IanBenzMaxim 1:e1c7c1c636af 71 }
IanBenzMaxim 1:e1c7c1c636af 72
IanBenzMaxim 1:e1c7c1c636af 73 return measure_delay_ms;
IanBenzMaxim 1:e1c7c1c636af 74 }
IanBenzMaxim 1:e1c7c1c636af 75
IanBenzMaxim 1:e1c7c1c636af 76 bool DS7505::read_temp_sensor_data(uint16_t & sensor_data) const
IanBenzMaxim 1:e1c7c1c636af 77 {
IanBenzMaxim 1:e1c7c1c636af 78 bool result;
IanBenzMaxim 1:e1c7c1c636af 79 uint8_t upperByte, lowerByte;
IanBenzMaxim 1:e1c7c1c636af 80 int sub_res;
IanBenzMaxim 1:e1c7c1c636af 81
IanBenzMaxim 1:e1c7c1c636af 82 sensor_data = 0;
IanBenzMaxim 1:e1c7c1c636af 83 m_I2C_interface.start();
IanBenzMaxim 1:e1c7c1c636af 84 sub_res = m_I2C_interface.write(m_I2C_address | I2C_READ);
IanBenzMaxim 1:e1c7c1c636af 85 if (sub_res == I2C_WRITE_OK)
IanBenzMaxim 1:e1c7c1c636af 86 {
IanBenzMaxim 6:b6bafd0a7013 87 upperByte = m_I2C_interface.read(mbed::I2C::ACK);
IanBenzMaxim 6:b6bafd0a7013 88 lowerByte = m_I2C_interface.read(mbed::I2C::NoACK);
IanBenzMaxim 1:e1c7c1c636af 89 }
IanBenzMaxim 1:e1c7c1c636af 90 m_I2C_interface.stop();
IanBenzMaxim 1:e1c7c1c636af 91 if (sub_res == I2C_WRITE_OK)
IanBenzMaxim 1:e1c7c1c636af 92 {
IanBenzMaxim 1:e1c7c1c636af 93 sensor_data = ((((uint16_t)upperByte) << 8) | lowerByte);
IanBenzMaxim 1:e1c7c1c636af 94 result = true;
IanBenzMaxim 1:e1c7c1c636af 95 }
IanBenzMaxim 1:e1c7c1c636af 96 else
IanBenzMaxim 1:e1c7c1c636af 97 {
IanBenzMaxim 1:e1c7c1c636af 98 // Handle hardware malfunction
IanBenzMaxim 1:e1c7c1c636af 99 result = false;
IanBenzMaxim 1:e1c7c1c636af 100 }
IanBenzMaxim 1:e1c7c1c636af 101
IanBenzMaxim 1:e1c7c1c636af 102 return result;
IanBenzMaxim 1:e1c7c1c636af 103 }
IanBenzMaxim 1:e1c7c1c636af 104
IanBenzMaxim 1:e1c7c1c636af 105 bool DS7505::set_register_pointer(Register pointer_reg) const
IanBenzMaxim 1:e1c7c1c636af 106 {
IanBenzMaxim 1:e1c7c1c636af 107 int res;
IanBenzMaxim 1:e1c7c1c636af 108
IanBenzMaxim 1:e1c7c1c636af 109 m_I2C_interface.start();
IanBenzMaxim 1:e1c7c1c636af 110 res = m_I2C_interface.write(m_I2C_address | I2C_WRITE);
IanBenzMaxim 1:e1c7c1c636af 111 if (res == I2C_WRITE_OK)
IanBenzMaxim 1:e1c7c1c636af 112 {
IanBenzMaxim 1:e1c7c1c636af 113 res = m_I2C_interface.write(pointer_reg);
IanBenzMaxim 1:e1c7c1c636af 114 }
IanBenzMaxim 1:e1c7c1c636af 115 m_I2C_interface.stop();
IanBenzMaxim 1:e1c7c1c636af 116
IanBenzMaxim 1:e1c7c1c636af 117 return (res == I2C_WRITE_OK);
IanBenzMaxim 1:e1c7c1c636af 118 }
IanBenzMaxim 1:e1c7c1c636af 119
IanBenzMaxim 1:e1c7c1c636af 120 bool DS7505::write_register(Register write_reg, uint8_t write_val) const
IanBenzMaxim 1:e1c7c1c636af 121 {
IanBenzMaxim 1:e1c7c1c636af 122 bool res;
IanBenzMaxim 1:e1c7c1c636af 123
IanBenzMaxim 1:e1c7c1c636af 124 m_I2C_interface.start();
IanBenzMaxim 1:e1c7c1c636af 125 res = m_I2C_interface.write(m_I2C_address | I2C_WRITE);
IanBenzMaxim 1:e1c7c1c636af 126 if (res == I2C_WRITE_OK)
IanBenzMaxim 1:e1c7c1c636af 127 {
IanBenzMaxim 1:e1c7c1c636af 128 res = m_I2C_interface.write(write_reg);
IanBenzMaxim 1:e1c7c1c636af 129 if (res == I2C_WRITE_OK)
IanBenzMaxim 1:e1c7c1c636af 130 res = m_I2C_interface.write(write_val);
IanBenzMaxim 1:e1c7c1c636af 131 }
IanBenzMaxim 1:e1c7c1c636af 132 m_I2C_interface.stop();
IanBenzMaxim 1:e1c7c1c636af 133
IanBenzMaxim 1:e1c7c1c636af 134 return (res == I2C_WRITE_OK);
IanBenzMaxim 1:e1c7c1c636af 135 }
IanBenzMaxim 1:e1c7c1c636af 136
IanBenzMaxim 1:e1c7c1c636af 137 bool DS7505::write_current_config() const
IanBenzMaxim 1:e1c7c1c636af 138 {
IanBenzMaxim 1:e1c7c1c636af 139 uint8_t DS7505_Config_Val = m_current_config.resolution;
IanBenzMaxim 1:e1c7c1c636af 140 if (m_current_config.enable_shutdown_mode)
IanBenzMaxim 1:e1c7c1c636af 141 DS7505_Config_Val |= DS7505_Config_SD_Bit;
IanBenzMaxim 1:e1c7c1c636af 142 return write_register(Configuration_Reg, DS7505_Config_Val);
IanBenzMaxim 1:e1c7c1c636af 143 }
IanBenzMaxim 1:e1c7c1c636af 144
IanBenzMaxim 1:e1c7c1c636af 145 DS7505::Result DS7505::set_resolution(uint8_t resolution)
IanBenzMaxim 1:e1c7c1c636af 146 {
IanBenzMaxim 1:e1c7c1c636af 147 switch (resolution)
IanBenzMaxim 1:e1c7c1c636af 148 {
IanBenzMaxim 1:e1c7c1c636af 149 case 1:
IanBenzMaxim 1:e1c7c1c636af 150 m_current_config.resolution = Config_9b_Res;
IanBenzMaxim 1:e1c7c1c636af 151 break;
IanBenzMaxim 1:e1c7c1c636af 152 case 2:
IanBenzMaxim 1:e1c7c1c636af 153 m_current_config.resolution = Config_10b_Res;
IanBenzMaxim 1:e1c7c1c636af 154 break;
IanBenzMaxim 1:e1c7c1c636af 155 case 3:
IanBenzMaxim 1:e1c7c1c636af 156 m_current_config.resolution = Config_11b_Res;
IanBenzMaxim 1:e1c7c1c636af 157 break;
IanBenzMaxim 1:e1c7c1c636af 158 case 4:
IanBenzMaxim 1:e1c7c1c636af 159 m_current_config.resolution = Config_12b_Res;
IanBenzMaxim 1:e1c7c1c636af 160 break;
IanBenzMaxim 1:e1c7c1c636af 161 default:
IanBenzMaxim 1:e1c7c1c636af 162 return Out_of_Range;
IanBenzMaxim 1:e1c7c1c636af 163 }
IanBenzMaxim 1:e1c7c1c636af 164
IanBenzMaxim 1:e1c7c1c636af 165 // Write DS7505 configuration
IanBenzMaxim 1:e1c7c1c636af 166 if (!write_current_config())
IanBenzMaxim 1:e1c7c1c636af 167 {
IanBenzMaxim 1:e1c7c1c636af 168 // Handle hardware malfunction
IanBenzMaxim 1:e1c7c1c636af 169 return Hardware_Failure;
IanBenzMaxim 1:e1c7c1c636af 170 }
IanBenzMaxim 1:e1c7c1c636af 171
IanBenzMaxim 1:e1c7c1c636af 172 // Set pointer to temperature register
IanBenzMaxim 1:e1c7c1c636af 173 if (!set_register_pointer(Temperature_Reg))
IanBenzMaxim 1:e1c7c1c636af 174 {
IanBenzMaxim 1:e1c7c1c636af 175 // Handle hardware malfunction
IanBenzMaxim 1:e1c7c1c636af 176 return Hardware_Failure;
IanBenzMaxim 1:e1c7c1c636af 177 }
IanBenzMaxim 1:e1c7c1c636af 178
IanBenzMaxim 1:e1c7c1c636af 179 return Success;
IanBenzMaxim 1:e1c7c1c636af 180 }
IanBenzMaxim 1:e1c7c1c636af 181
IanBenzMaxim 1:e1c7c1c636af 182 DS7505::Result DS7505::read_temp_sensor(uint16_t & sensor_data) const
IanBenzMaxim 1:e1c7c1c636af 183 {
IanBenzMaxim 1:e1c7c1c636af 184 bool res;
IanBenzMaxim 1:e1c7c1c636af 185
IanBenzMaxim 1:e1c7c1c636af 186 if (m_current_config.enable_shutdown_mode)
IanBenzMaxim 1:e1c7c1c636af 187 {
IanBenzMaxim 1:e1c7c1c636af 188 // Disable shutdown mode
IanBenzMaxim 1:e1c7c1c636af 189 m_current_config.enable_shutdown_mode = false;
IanBenzMaxim 1:e1c7c1c636af 190 res = write_current_config();
IanBenzMaxim 1:e1c7c1c636af 191 if (!res)
IanBenzMaxim 1:e1c7c1c636af 192 return Hardware_Failure;
IanBenzMaxim 1:e1c7c1c636af 193
IanBenzMaxim 1:e1c7c1c636af 194 // DS7505 measures temperature
IanBenzMaxim 1:e1c7c1c636af 195
IanBenzMaxim 1:e1c7c1c636af 196 // Enable shutdown mode
IanBenzMaxim 1:e1c7c1c636af 197 m_current_config.enable_shutdown_mode = true;
IanBenzMaxim 1:e1c7c1c636af 198 res = write_current_config();
IanBenzMaxim 1:e1c7c1c636af 199 if (!res)
IanBenzMaxim 1:e1c7c1c636af 200 return Hardware_Failure;
IanBenzMaxim 1:e1c7c1c636af 201
IanBenzMaxim 1:e1c7c1c636af 202 // Set pointer to temperature register
IanBenzMaxim 1:e1c7c1c636af 203 res = set_register_pointer(Temperature_Reg);
IanBenzMaxim 1:e1c7c1c636af 204 if (!res)
IanBenzMaxim 1:e1c7c1c636af 205 return Hardware_Failure;
IanBenzMaxim 1:e1c7c1c636af 206
IanBenzMaxim 1:e1c7c1c636af 207 // Sleep for maximum time needed for sample
IanBenzMaxim 1:e1c7c1c636af 208 wait_ms(get_measure_delay_ms(m_current_config.resolution));
IanBenzMaxim 1:e1c7c1c636af 209 }
IanBenzMaxim 1:e1c7c1c636af 210 // else: shutdown mode disabled
IanBenzMaxim 1:e1c7c1c636af 211 // DS7505 is constantly measuring temperature
IanBenzMaxim 1:e1c7c1c636af 212
IanBenzMaxim 1:e1c7c1c636af 213 // Read temperature from sensor
IanBenzMaxim 1:e1c7c1c636af 214 if (!read_temp_sensor_data(sensor_data))
IanBenzMaxim 1:e1c7c1c636af 215 {
IanBenzMaxim 1:e1c7c1c636af 216 return Hardware_Failure;
IanBenzMaxim 1:e1c7c1c636af 217 }
IanBenzMaxim 1:e1c7c1c636af 218
IanBenzMaxim 1:e1c7c1c636af 219 return Success;
IanBenzMaxim 1:e1c7c1c636af 220 }
IanBenzMaxim 1:e1c7c1c636af 221
IanBenzMaxim 1:e1c7c1c636af 222 DS7505::Result DS7505::read_current_temp(int16_t & temperature) const
IanBenzMaxim 1:e1c7c1c636af 223 {
IanBenzMaxim 1:e1c7c1c636af 224 uint16_t sensor_data;
IanBenzMaxim 1:e1c7c1c636af 225 Result result;
IanBenzMaxim 1:e1c7c1c636af 226
IanBenzMaxim 1:e1c7c1c636af 227 result = read_temp_sensor(sensor_data);
IanBenzMaxim 1:e1c7c1c636af 228 if (result == Success)
IanBenzMaxim 1:e1c7c1c636af 229 {
IanBenzMaxim 1:e1c7c1c636af 230 // Convert temperature to have an exponent of 10^-2
IanBenzMaxim 1:e1c7c1c636af 231 temperature = ((int8_t)(sensor_data >> 8)) * 100;
IanBenzMaxim 1:e1c7c1c636af 232 if (sensor_data & 0x0080)
IanBenzMaxim 1:e1c7c1c636af 233 temperature += 50; // 0.5
IanBenzMaxim 1:e1c7c1c636af 234 if (sensor_data & 0x0040)
IanBenzMaxim 1:e1c7c1c636af 235 temperature += 25; // 0.25
IanBenzMaxim 1:e1c7c1c636af 236 if (sensor_data & 0x0020)
IanBenzMaxim 1:e1c7c1c636af 237 temperature += 13; // 0.125
IanBenzMaxim 1:e1c7c1c636af 238 if (sensor_data & 0x0010)
IanBenzMaxim 1:e1c7c1c636af 239 temperature += 6; // 0.0625
IanBenzMaxim 1:e1c7c1c636af 240 }
IanBenzMaxim 1:e1c7c1c636af 241 return result;
IanBenzMaxim 1:e1c7c1c636af 242 }
IanBenzMaxim 1:e1c7c1c636af 243
IanBenzMaxim 1:e1c7c1c636af 244 DS7505::Result DS7505::read_current_temp(double & temperature) const
IanBenzMaxim 1:e1c7c1c636af 245 {
IanBenzMaxim 1:e1c7c1c636af 246 uint16_t sensor_data;
IanBenzMaxim 1:e1c7c1c636af 247 Result result;
IanBenzMaxim 1:e1c7c1c636af 248
IanBenzMaxim 1:e1c7c1c636af 249 result = read_temp_sensor(sensor_data);
IanBenzMaxim 1:e1c7c1c636af 250 if (result == Success)
IanBenzMaxim 1:e1c7c1c636af 251 {
IanBenzMaxim 1:e1c7c1c636af 252 // Convert sensor data to floating-point temperature
IanBenzMaxim 1:e1c7c1c636af 253 temperature = ((int8_t)(sensor_data >> 8));
IanBenzMaxim 1:e1c7c1c636af 254 if (sensor_data & 0x0080)
IanBenzMaxim 1:e1c7c1c636af 255 temperature += 0.5;
IanBenzMaxim 1:e1c7c1c636af 256 if (sensor_data & 0x0040)
IanBenzMaxim 1:e1c7c1c636af 257 temperature += 0.25;
IanBenzMaxim 1:e1c7c1c636af 258 if (sensor_data & 0x0020)
IanBenzMaxim 1:e1c7c1c636af 259 temperature += 0.125;
IanBenzMaxim 1:e1c7c1c636af 260 if (sensor_data & 0x0010)
IanBenzMaxim 1:e1c7c1c636af 261 temperature += 0.0625;
IanBenzMaxim 1:e1c7c1c636af 262 }
IanBenzMaxim 1:e1c7c1c636af 263 return result;
IanBenzMaxim 1:e1c7c1c636af 264 }
IanBenzMaxim 1:e1c7c1c636af 265
IanBenzMaxim 1:e1c7c1c636af 266 DS7505::Result DS7505::read_current_temp(int8_t & temperature) const
IanBenzMaxim 1:e1c7c1c636af 267 {
IanBenzMaxim 1:e1c7c1c636af 268 uint16_t sensor_data;
IanBenzMaxim 1:e1c7c1c636af 269 Result result;
IanBenzMaxim 1:e1c7c1c636af 270
IanBenzMaxim 1:e1c7c1c636af 271 result = read_temp_sensor(sensor_data);
IanBenzMaxim 1:e1c7c1c636af 272 if (result == Success)
IanBenzMaxim 1:e1c7c1c636af 273 {
IanBenzMaxim 1:e1c7c1c636af 274 // Convert sensor data to integer temperature
IanBenzMaxim 1:e1c7c1c636af 275 temperature = ((int8_t)(sensor_data >> 8));
IanBenzMaxim 1:e1c7c1c636af 276 }
IanBenzMaxim 1:e1c7c1c636af 277 return result;
IanBenzMaxim 1:e1c7c1c636af 278 }