Wim Huiskamp / LM77

LM77 Temperature sensor with I2C interface. Provides temperature in celsius and fahrenheit. The device also supports temperature alerts.

Dependents:   mbed_HP03SA_LM77

LM77.cpp@0:8e812deb9f66, 2015-01-10 (annotated)

Committer:
wim
Date:
Sat Jan 10 19:10:40 2015 +0000
Revision:
0:8e812deb9f66
First version of LM77 library.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
wim 0:8e812deb9f66 1 /* mbed LM77 Library, for an I2C Temperature sensor
wim 0:8e812deb9f66 2 * Copyright (c) 2015, v01: WH, Initial version
wim 0:8e812deb9f66 3 *
wim 0:8e812deb9f66 4 * The LM77 is a digital temperature sensor and thermal window comparator with an I2C Serial Bus interface.
wim 0:8e812deb9f66 5 * The open-drain Interrupt (INT) output becomes active whenever temperature goes outside a programmable window,
wim 0:8e812deb9f66 6 * while a separate Critical Temperature Alarm (T_CRIT_A) output becomes active when the temperature exceeds a
wim 0:8e812deb9f66 7 * programmable critical limit. The INT output can operate in either a comparator or event mode, while the T_CRIT_A
wim 0:8e812deb9f66 8 * output operates in comparator mode only. The host can program both the upper and lower limits of the window as
wim 0:8e812deb9f66 9 * well as the critical temperature limit. Programmable hysterisis as well as a fault queue are available to minimize
wim 0:8e812deb9f66 10 * false tripping. Two pins (A0, A1) are available for address selection. The sensor powers up with default thresholds
wim 0:8e812deb9f66 11 * of 2°C THYST, 10°C TLOW, 64°C THIGH, and 80°C TCRIT.
wim 0:8e812deb9f66 12 *
wim 0:8e812deb9f66 13 * Permission is hereby granted, free of charge, to any person obtaining a copy
wim 0:8e812deb9f66 14 * of this software and associated documentation files (the "Software"), to deal
wim 0:8e812deb9f66 15 * in the Software without restriction, including without limitation the rights
wim 0:8e812deb9f66 16 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
wim 0:8e812deb9f66 17 * copies of the Software, and to permit persons to whom the Software is
wim 0:8e812deb9f66 18 * furnished to do so, subject to the following conditions:
wim 0:8e812deb9f66 19 *
wim 0:8e812deb9f66 20 * The above copyright notice and this permission notice shall be included in
wim 0:8e812deb9f66 21 * all copies or substantial portions of the Software.
wim 0:8e812deb9f66 22 *
wim 0:8e812deb9f66 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
wim 0:8e812deb9f66 24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
wim 0:8e812deb9f66 25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
wim 0:8e812deb9f66 26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
wim 0:8e812deb9f66 27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
wim 0:8e812deb9f66 28 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
wim 0:8e812deb9f66 29 * THE SOFTWARE.
wim 0:8e812deb9f66 30 */
wim 0:8e812deb9f66 31 #include "LM77.h"
wim 0:8e812deb9f66 32
wim 0:8e812deb9f66 33 /** Create an LM77 device instance
wim 0:8e812deb9f66 34 *
wim 0:8e812deb9f66 35 * @param i2c I2C Bus
wim 0:8e812deb9f66 36 * @param char deviceAddress I2C slaveaddress
wim 0:8e812deb9f66 37 */
wim 0:8e812deb9f66 38 LM77::LM77(I2C *i2c, char deviceAddress) : _i2c(i2c), _slaveAddress(deviceAddress) {
wim 0:8e812deb9f66 39
wim 0:8e812deb9f66 40 }
wim 0:8e812deb9f66 41
wim 0:8e812deb9f66 42 /** Get Status
wim 0:8e812deb9f66 43 *
wim 0:8e812deb9f66 44 * @return bool Sensor ready
wim 0:8e812deb9f66 45 */
wim 0:8e812deb9f66 46 bool LM77::getStatus(void) {
wim 0:8e812deb9f66 47 char buffer[2];
wim 0:8e812deb9f66 48 int status;
wim 0:8e812deb9f66 49
wim 0:8e812deb9f66 50 // Dummy operation to check status
wim 0:8e812deb9f66 51 buffer[0] = 0x00;
wim 0:8e812deb9f66 52 status=_i2c->write(_slaveAddress, buffer, 0);
wim 0:8e812deb9f66 53
wim 0:8e812deb9f66 54 return (status==0); // True when device found
wim 0:8e812deb9f66 55 }
wim 0:8e812deb9f66 56
wim 0:8e812deb9f66 57
wim 0:8e812deb9f66 58 /** Get the current power mode of the LM77
wim 0:8e812deb9f66 59 *
wim 0:8e812deb9f66 60 * @returns The current power mode as a PowerMode enum.
wim 0:8e812deb9f66 61 */
wim 0:8e812deb9f66 62 LM77::PowerMode LM77::getPowerMode() {
wim 0:8e812deb9f66 63
wim 0:8e812deb9f66 64 //Read the 8-bit register value
wim 0:8e812deb9f66 65 char value = _readReg8(LM77_REG_CONF);
wim 0:8e812deb9f66 66
wim 0:8e812deb9f66 67 //Return the status of the SHUTDOWN bit
wim 0:8e812deb9f66 68 if (value & LM77_PWR_MSK) {
wim 0:8e812deb9f66 69 return POWER_SHUTDOWN;
wim 0:8e812deb9f66 70 }
wim 0:8e812deb9f66 71 else {
wim 0:8e812deb9f66 72 return POWER_NORMAL;
wim 0:8e812deb9f66 73 }
wim 0:8e812deb9f66 74 }
wim 0:8e812deb9f66 75
wim 0:8e812deb9f66 76
wim 0:8e812deb9f66 77 /** Set the power mode of the LM77
wim 0:8e812deb9f66 78 *
wim 0:8e812deb9f66 79 * @param mode The new power mode as a PowerMode enum.
wim 0:8e812deb9f66 80 */
wim 0:8e812deb9f66 81 void LM77::setPowerMode(PowerMode mode) {
wim 0:8e812deb9f66 82
wim 0:8e812deb9f66 83 //Read the current 8-bit register value
wim 0:8e812deb9f66 84 char value = _readReg8(LM77_REG_CONF);
wim 0:8e812deb9f66 85
wim 0:8e812deb9f66 86 //Set or clear the SHUTDOWN bit
wim 0:8e812deb9f66 87 if (mode == POWER_SHUTDOWN) {
wim 0:8e812deb9f66 88 value |= LM77_PWR_DWN;
wim 0:8e812deb9f66 89 }
wim 0:8e812deb9f66 90 else {
wim 0:8e812deb9f66 91 value &= ~LM77_PWR_DWN;
wim 0:8e812deb9f66 92 }
wim 0:8e812deb9f66 93
wim 0:8e812deb9f66 94 //Write the value back out
wim 0:8e812deb9f66 95 _writeReg8(LM77_REG_CONF, value);
wim 0:8e812deb9f66 96 }
wim 0:8e812deb9f66 97
wim 0:8e812deb9f66 98
wim 0:8e812deb9f66 99 /** Get the current INT pin mode of the LM77
wim 0:8e812deb9f66 100 *
wim 0:8e812deb9f66 101 * @returns The current INT pin mode as an IntMode enum.
wim 0:8e812deb9f66 102 */
wim 0:8e812deb9f66 103 LM77::IntMode LM77::getIntMode() {
wim 0:8e812deb9f66 104
wim 0:8e812deb9f66 105 //Read the 8-bit register value
wim 0:8e812deb9f66 106 char value = _readReg8(LM77_REG_CONF);
wim 0:8e812deb9f66 107
wim 0:8e812deb9f66 108 //Return the status of the INT_MODE bit
wim 0:8e812deb9f66 109 if (value & LM77_INT_MSK) {
wim 0:8e812deb9f66 110 return INT_EVENT;
wim 0:8e812deb9f66 111 }
wim 0:8e812deb9f66 112 else {
wim 0:8e812deb9f66 113 return INT_COMPARATOR;
wim 0:8e812deb9f66 114 }
wim 0:8e812deb9f66 115 }
wim 0:8e812deb9f66 116
wim 0:8e812deb9f66 117
wim 0:8e812deb9f66 118 /** Set the INT pin mode of the LM77
wim 0:8e812deb9f66 119 *
wim 0:8e812deb9f66 120 * @param mode The new INT pin mode as an IntMode enum.
wim 0:8e812deb9f66 121 */
wim 0:8e812deb9f66 122 void LM77::setIntMode(IntMode mode) {
wim 0:8e812deb9f66 123
wim 0:8e812deb9f66 124 //Read the current 8-bit register value
wim 0:8e812deb9f66 125 char value = _readReg8(LM77_REG_CONF);
wim 0:8e812deb9f66 126
wim 0:8e812deb9f66 127 //Set or clear the OS_COMP_INT bit
wim 0:8e812deb9f66 128 if (mode == INT_EVENT) {
wim 0:8e812deb9f66 129 value |= LM77_INT_EVENT;
wim 0:8e812deb9f66 130 }
wim 0:8e812deb9f66 131 else {
wim 0:8e812deb9f66 132 // Comparator mode
wim 0:8e812deb9f66 133 value &= ~LM77_INT_EVENT;
wim 0:8e812deb9f66 134 }
wim 0:8e812deb9f66 135
wim 0:8e812deb9f66 136 //Write the value back out
wim 0:8e812deb9f66 137 _writeReg8(LM77_REG_CONF, value);
wim 0:8e812deb9f66 138 }
wim 0:8e812deb9f66 139
wim 0:8e812deb9f66 140
wim 0:8e812deb9f66 141 /** Get the current INT pin polarity of the LM77
wim 0:8e812deb9f66 142 *
wim 0:8e812deb9f66 143 * @returns The current INT pin polarity as an PinPolarity enum.
wim 0:8e812deb9f66 144 */
wim 0:8e812deb9f66 145 LM77::PinPolarity LM77::getIntPolarity() {
wim 0:8e812deb9f66 146
wim 0:8e812deb9f66 147 //Read the 8-bit register value
wim 0:8e812deb9f66 148 char value = _readReg8(LM77_REG_CONF);
wim 0:8e812deb9f66 149
wim 0:8e812deb9f66 150 //Return the status of the POL_INT bit
wim 0:8e812deb9f66 151 if (value & LM77_POL_INT_MSK) {
wim 0:8e812deb9f66 152 return ACTIVE_HIGH;
wim 0:8e812deb9f66 153 }
wim 0:8e812deb9f66 154 else {
wim 0:8e812deb9f66 155 return ACTIVE_LOW;
wim 0:8e812deb9f66 156 }
wim 0:8e812deb9f66 157 }
wim 0:8e812deb9f66 158
wim 0:8e812deb9f66 159 /** Set the INT pin polarity of the LM77
wim 0:8e812deb9f66 160 *
wim 0:8e812deb9f66 161 * @param polarity The new INT pin polarity as an PinPolarity enum.
wim 0:8e812deb9f66 162 */
wim 0:8e812deb9f66 163 void LM77::setIntPolarity(PinPolarity polarity)
wim 0:8e812deb9f66 164 {
wim 0:8e812deb9f66 165 //Read the current 8-bit register value
wim 0:8e812deb9f66 166 char value = _readReg8(LM77_REG_CONF);
wim 0:8e812deb9f66 167
wim 0:8e812deb9f66 168 //Set or clear the POL_INT bit
wim 0:8e812deb9f66 169 if (polarity == ACTIVE_HIGH) {
wim 0:8e812deb9f66 170 value |= LM77_POL_INT_H;
wim 0:8e812deb9f66 171 }
wim 0:8e812deb9f66 172 else {
wim 0:8e812deb9f66 173 value &= ~LM77_POL_INT_H;
wim 0:8e812deb9f66 174 }
wim 0:8e812deb9f66 175
wim 0:8e812deb9f66 176 //Write the value back out
wim 0:8e812deb9f66 177 _writeReg8(LM77_REG_CONF, value);
wim 0:8e812deb9f66 178 }
wim 0:8e812deb9f66 179
wim 0:8e812deb9f66 180 /** Get the current T_CRIT_A pin polarity of the LM77
wim 0:8e812deb9f66 181 *
wim 0:8e812deb9f66 182 * @returns The current T_CRIT_A pin polarity as an PinPolarity enum.
wim 0:8e812deb9f66 183 */
wim 0:8e812deb9f66 184 LM77::PinPolarity LM77::getTCritPolarity() {
wim 0:8e812deb9f66 185
wim 0:8e812deb9f66 186 //Read the 8-bit register value
wim 0:8e812deb9f66 187 char value = _readReg8(LM77_REG_CONF);
wim 0:8e812deb9f66 188
wim 0:8e812deb9f66 189 //Return the status of the POL_TCRIT bit
wim 0:8e812deb9f66 190 if (value & LM77_POL_TCRIT_MSK) {
wim 0:8e812deb9f66 191 return ACTIVE_HIGH;
wim 0:8e812deb9f66 192 }
wim 0:8e812deb9f66 193 else {
wim 0:8e812deb9f66 194 return ACTIVE_LOW;
wim 0:8e812deb9f66 195 }
wim 0:8e812deb9f66 196 }
wim 0:8e812deb9f66 197
wim 0:8e812deb9f66 198 /** Set the T_CRIT_A pin polarity of the LM77
wim 0:8e812deb9f66 199 *
wim 0:8e812deb9f66 200 * @param polarity The new T_CRIT_A pin polarity as an PinPolarity enum.
wim 0:8e812deb9f66 201 */
wim 0:8e812deb9f66 202 void LM77::setTCritPolarity(PinPolarity polarity)
wim 0:8e812deb9f66 203 {
wim 0:8e812deb9f66 204 //Read the current 8-bit register value
wim 0:8e812deb9f66 205 char value = _readReg8(LM77_REG_CONF);
wim 0:8e812deb9f66 206
wim 0:8e812deb9f66 207 //Set or clear the POL_TCRIT bit
wim 0:8e812deb9f66 208 if (polarity == ACTIVE_HIGH) {
wim 0:8e812deb9f66 209 value |= LM77_POL_TCRIT_H;
wim 0:8e812deb9f66 210 }
wim 0:8e812deb9f66 211 else {
wim 0:8e812deb9f66 212 value &= ~LM77_POL_TCRIT_H;
wim 0:8e812deb9f66 213 }
wim 0:8e812deb9f66 214
wim 0:8e812deb9f66 215 //Write the value back out
wim 0:8e812deb9f66 216 _writeReg8(LM77_REG_CONF, value);
wim 0:8e812deb9f66 217 }
wim 0:8e812deb9f66 218
wim 0:8e812deb9f66 219
wim 0:8e812deb9f66 220 /** Get the current pin and flag fault queue length of the LM77
wim 0:8e812deb9f66 221 *
wim 0:8e812deb9f66 222 * @returns The current pin and flag fault queue length as an FaultQueue enum.
wim 0:8e812deb9f66 223 */
wim 0:8e812deb9f66 224 LM77::FaultQueue LM77::getFaultQueue()
wim 0:8e812deb9f66 225 {
wim 0:8e812deb9f66 226 //Read the 8-bit register value
wim 0:8e812deb9f66 227 char value = _readReg8(LM77_REG_CONF);
wim 0:8e812deb9f66 228
wim 0:8e812deb9f66 229 //Return the status of the FAULT_QUE bit
wim 0:8e812deb9f66 230 if (value & LM77_FQU_MSK) {
wim 0:8e812deb9f66 231 return FAULT_QUEUE_4;
wim 0:8e812deb9f66 232 }
wim 0:8e812deb9f66 233 else {
wim 0:8e812deb9f66 234 return FAULT_QUEUE_1;
wim 0:8e812deb9f66 235 }
wim 0:8e812deb9f66 236 }
wim 0:8e812deb9f66 237
wim 0:8e812deb9f66 238
wim 0:8e812deb9f66 239 /** Set the pin and flag fault queue length of the LM77
wim 0:8e812deb9f66 240 *
wim 0:8e812deb9f66 241 * @param queue The new pin and flag fault queue length as an FaultQueue enum.
wim 0:8e812deb9f66 242 */
wim 0:8e812deb9f66 243 void LM77::setFaultQueue(FaultQueue queue)
wim 0:8e812deb9f66 244 {
wim 0:8e812deb9f66 245 //Read the current 8-bit register value
wim 0:8e812deb9f66 246 char value = _readReg8(LM77_REG_CONF);
wim 0:8e812deb9f66 247
wim 0:8e812deb9f66 248 //Set the new FAULT_QUE bit
wim 0:8e812deb9f66 249 if (queue == FAULT_QUEUE_4) {
wim 0:8e812deb9f66 250 value |= LM77_FQU_4;
wim 0:8e812deb9f66 251 }
wim 0:8e812deb9f66 252 else {
wim 0:8e812deb9f66 253 value &= ~LM77_FQU_4;
wim 0:8e812deb9f66 254 }
wim 0:8e812deb9f66 255
wim 0:8e812deb9f66 256 //Write the value back out
wim 0:8e812deb9f66 257 _writeReg8(LM77_REG_CONF, value);
wim 0:8e812deb9f66 258 }
wim 0:8e812deb9f66 259
wim 0:8e812deb9f66 260 /** Get the current Critical alert temperature threshold of the LM77
wim 0:8e812deb9f66 261 * Reset value is 80.0 °C.
wim 0:8e812deb9f66 262 *
wim 0:8e812deb9f66 263 * @returns The current Critical alert temperature threshold in °C.
wim 0:8e812deb9f66 264 */
wim 0:8e812deb9f66 265 float LM77::getCritAlertTemp() {
wim 0:8e812deb9f66 266
wim 0:8e812deb9f66 267 //Use the 9-bit helper to read the TCRIT register
wim 0:8e812deb9f66 268 return _readTempHelper(LM77_REG_TCRIT);
wim 0:8e812deb9f66 269 }
wim 0:8e812deb9f66 270
wim 0:8e812deb9f66 271 /** Set the critical alert temperature threshold of the LM77
wim 0:8e812deb9f66 272 * Reset value is 80.0 °C.
wim 0:8e812deb9f66 273 *
wim 0:8e812deb9f66 274 * @param temp The new critical alert temperature threshold in °C.
wim 0:8e812deb9f66 275 */
wim 0:8e812deb9f66 276 void LM77::setCritAlertTemp(float temp) {
wim 0:8e812deb9f66 277
wim 0:8e812deb9f66 278 //Use the 9-bit helper to write to the TCRIT register
wim 0:8e812deb9f66 279 _writeTempHelper(LM77_REG_TCRIT, temp);
wim 0:8e812deb9f66 280 }
wim 0:8e812deb9f66 281
wim 0:8e812deb9f66 282 /** Get the current Low temperature alert threshold of the LM77
wim 0:8e812deb9f66 283 * Reset value is 10.0 °C.
wim 0:8e812deb9f66 284 *
wim 0:8e812deb9f66 285 * @returns The current Low temperature alert threshold in °C.
wim 0:8e812deb9f66 286 */
wim 0:8e812deb9f66 287 float LM77::getLowAlertTemp() {
wim 0:8e812deb9f66 288
wim 0:8e812deb9f66 289 //Use the 9-bit helper to read the TLOW register
wim 0:8e812deb9f66 290 return _readTempHelper(LM77_REG_TLOW);
wim 0:8e812deb9f66 291 }
wim 0:8e812deb9f66 292
wim 0:8e812deb9f66 293 /** Set the current Low temperature alert threshold of the LM77
wim 0:8e812deb9f66 294 * Reset value is 10.0 °C.
wim 0:8e812deb9f66 295 *
wim 0:8e812deb9f66 296 * @param temp The new Low alert temperature threshold in °C.
wim 0:8e812deb9f66 297 */
wim 0:8e812deb9f66 298 void LM77::setLowAlertTemp(float temp){
wim 0:8e812deb9f66 299
wim 0:8e812deb9f66 300 //Use the 9-bit helper to write to the TLOW register
wim 0:8e812deb9f66 301 _writeTempHelper(LM77_REG_TLOW, temp);
wim 0:8e812deb9f66 302 }
wim 0:8e812deb9f66 303
wim 0:8e812deb9f66 304 /** Get the current High temperature alert threshold of the LM77
wim 0:8e812deb9f66 305 * Reset value is 64.0 °C.
wim 0:8e812deb9f66 306 *
wim 0:8e812deb9f66 307 * @returns The current High temperature alert threshold in °C.
wim 0:8e812deb9f66 308 */
wim 0:8e812deb9f66 309 float LM77::getHighAlertTemp(){
wim 0:8e812deb9f66 310
wim 0:8e812deb9f66 311 //Use the 9-bit helper to read the THIGH register
wim 0:8e812deb9f66 312 return _readTempHelper(LM77_REG_THIGH);
wim 0:8e812deb9f66 313 }
wim 0:8e812deb9f66 314
wim 0:8e812deb9f66 315 /** Set the High temperature alert threshold of the LM77
wim 0:8e812deb9f66 316 * Reset value is 64.0 °C.
wim 0:8e812deb9f66 317 *
wim 0:8e812deb9f66 318 * @param temp The new High temperature alert threshold in °C.
wim 0:8e812deb9f66 319 */
wim 0:8e812deb9f66 320 void LM77::setHighAlertTemp(float temp) {
wim 0:8e812deb9f66 321
wim 0:8e812deb9f66 322 //Use the 9-bit helper to write to the THIGH register
wim 0:8e812deb9f66 323 _writeTempHelper(LM77_REG_THIGH, temp);
wim 0:8e812deb9f66 324 }
wim 0:8e812deb9f66 325
wim 0:8e812deb9f66 326
wim 0:8e812deb9f66 327 /** Get the current alert temperature hysteresis of the LM77
wim 0:8e812deb9f66 328 * Reset value is 2.0 °C.
wim 0:8e812deb9f66 329 *
wim 0:8e812deb9f66 330 * @returns The current alert temperature hysteresis in °C.
wim 0:8e812deb9f66 331 */
wim 0:8e812deb9f66 332 float LM77::getAlertHyst() {
wim 0:8e812deb9f66 333
wim 0:8e812deb9f66 334 //Use the 9-bit helper to read the THYST register
wim 0:8e812deb9f66 335 return _readTempHelper(LM77_REG_THYST);
wim 0:8e812deb9f66 336 }
wim 0:8e812deb9f66 337
wim 0:8e812deb9f66 338 /** Set the alert temperature hysteresis of the LM77
wim 0:8e812deb9f66 339 * Reset value is 2.0 °C.
wim 0:8e812deb9f66 340 *
wim 0:8e812deb9f66 341 * @param temp The new alert temperature hysteresis in °C.
wim 0:8e812deb9f66 342 */
wim 0:8e812deb9f66 343 void LM77::setAlertHyst(float temp) {
wim 0:8e812deb9f66 344
wim 0:8e812deb9f66 345 //Use the 9-bit helper to write to the THYST register
wim 0:8e812deb9f66 346 _writeTempHelper(LM77_REG_THYST, temp);
wim 0:8e812deb9f66 347 }
wim 0:8e812deb9f66 348
wim 0:8e812deb9f66 349
wim 0:8e812deb9f66 350 /** Get Temperature as int in °Celsius x 10
wim 0:8e812deb9f66 351 *
wim 0:8e812deb9f66 352 * @return int Temperature in °Celsius x 10
wim 0:8e812deb9f66 353 */
wim 0:8e812deb9f66 354 int LM77::getTemperatureInt(void) {
wim 0:8e812deb9f66 355
wim 0:8e812deb9f66 356 //Signed return value
wim 0:8e812deb9f66 357 int16_t value;
wim 0:8e812deb9f66 358
wim 0:8e812deb9f66 359 //Read the 9-bit raw temperature value in 0.5 degree resolution
wim 0:8e812deb9f66 360 value = _readReg16(LM77_REG_TEMP) >> 3;
wim 0:8e812deb9f66 361
wim 0:8e812deb9f66 362 //Sign extend negative numbers
wim 0:8e812deb9f66 363 if (value & (1 << 9))
wim 0:8e812deb9f66 364 value |= 0xFE00;
wim 0:8e812deb9f66 365
wim 0:8e812deb9f66 366 //Return the temperature in °C x 10
wim 0:8e812deb9f66 367 return (int) value * 5; // x 10 x 0.5
wim 0:8e812deb9f66 368 }
wim 0:8e812deb9f66 369
wim 0:8e812deb9f66 370 /** Get the Alert flags of the LM77
wim 0:8e812deb9f66 371 *
wim 0:8e812deb9f66 372 * @returns The current Alert flags as int.
wim 0:8e812deb9f66 373 */
wim 0:8e812deb9f66 374 int LM77::getAlertFlags() {
wim 0:8e812deb9f66 375
wim 0:8e812deb9f66 376 //Signed return value
wim 0:8e812deb9f66 377 int16_t value;
wim 0:8e812deb9f66 378
wim 0:8e812deb9f66 379 //Read the 9-bit raw temperature value and the flags
wim 0:8e812deb9f66 380 value = _readReg16(LM77_REG_TEMP);
wim 0:8e812deb9f66 381
wim 0:8e812deb9f66 382 //Return the flag bits
wim 0:8e812deb9f66 383 // LM77_FLAG_LOW 0x01
wim 0:8e812deb9f66 384 // LM77_FLAG_HIGH 0x02
wim 0:8e812deb9f66 385 // LM77_FLAG_CRIT 0x04
wim 0:8e812deb9f66 386 // LM77_FLAG_MSK 0x07
wim 0:8e812deb9f66 387 return (value & LM77_FLAG_MSK);
wim 0:8e812deb9f66 388 }
wim 0:8e812deb9f66 389
wim 0:8e812deb9f66 390
wim 0:8e812deb9f66 391 /** Get Temperature as float in °Celsius
wim 0:8e812deb9f66 392 *
wim 0:8e812deb9f66 393 * @return float Temperature in °Celsius
wim 0:8e812deb9f66 394 */
wim 0:8e812deb9f66 395 float LM77::getTemperature(void) {
wim 0:8e812deb9f66 396
wim 0:8e812deb9f66 397 return _readTempHelper(LM77_REG_TEMP);
wim 0:8e812deb9f66 398 }
wim 0:8e812deb9f66 399
wim 0:8e812deb9f66 400 #ifdef MBED_OPERATORS
wim 0:8e812deb9f66 401 LM77::operator float() {
wim 0:8e812deb9f66 402
wim 0:8e812deb9f66 403 //Return the current temperature reading
wim 0:8e812deb9f66 404 return getTemperature();
wim 0:8e812deb9f66 405 }
wim 0:8e812deb9f66 406 #endif
wim 0:8e812deb9f66 407
wim 0:8e812deb9f66 408 /** Convert Temperature from °Celsius into °Fahrenheit
wim 0:8e812deb9f66 409 *
wim 0:8e812deb9f66 410 * @param float celsius in °Celsius
wim 0:8e812deb9f66 411 * @return float temperature in °Fahrenheit
wim 0:8e812deb9f66 412 */
wim 0:8e812deb9f66 413 float LM77::celsiusToFahrenheit(float celsius) {
wim 0:8e812deb9f66 414
wim 0:8e812deb9f66 415 return ((celsius * 9.0f) / 5.0f) + 32.0f; // Convert to Fahrenheit
wim 0:8e812deb9f66 416 }
wim 0:8e812deb9f66 417
wim 0:8e812deb9f66 418
wim 0:8e812deb9f66 419 /** Read 8 bit value from register
wim 0:8e812deb9f66 420 *
wim 0:8e812deb9f66 421 * @param reg Index of register
wim 0:8e812deb9f66 422 * @return data value from register
wim 0:8e812deb9f66 423 */
wim 0:8e812deb9f66 424 char LM77::_readReg8(char reg) {
wim 0:8e812deb9f66 425
wim 0:8e812deb9f66 426 //Select the register
wim 0:8e812deb9f66 427 _i2c->write(_slaveAddress, &reg, 1, true);
wim 0:8e812deb9f66 428
wim 0:8e812deb9f66 429 //Read the 8-bit register
wim 0:8e812deb9f66 430 _i2c->read(_slaveAddress, &reg, 1);
wim 0:8e812deb9f66 431
wim 0:8e812deb9f66 432 //Return the byte
wim 0:8e812deb9f66 433 return reg;
wim 0:8e812deb9f66 434 }
wim 0:8e812deb9f66 435
wim 0:8e812deb9f66 436 /** Write 8 bit value to register
wim 0:8e812deb9f66 437 *
wim 0:8e812deb9f66 438 * @param reg Index of register
wim 0:8e812deb9f66 439 * @param data value to write
wim 0:8e812deb9f66 440 */
wim 0:8e812deb9f66 441 void LM77::_writeReg8(char reg, char data) {
wim 0:8e812deb9f66 442
wim 0:8e812deb9f66 443 //Create a temporary buffer
wim 0:8e812deb9f66 444 char buf[2];
wim 0:8e812deb9f66 445
wim 0:8e812deb9f66 446 //Load the register address and 8-bit data
wim 0:8e812deb9f66 447 buf[0] = reg;
wim 0:8e812deb9f66 448 buf[1] = data;
wim 0:8e812deb9f66 449
wim 0:8e812deb9f66 450 //Write the data
wim 0:8e812deb9f66 451 _i2c->write(_slaveAddress, buf, 2);
wim 0:8e812deb9f66 452 }
wim 0:8e812deb9f66 453
wim 0:8e812deb9f66 454 /** Read 16 bit value from register
wim 0:8e812deb9f66 455 * Used for Critical temp threshold, Low and High temp threshold window and Hysteresis
wim 0:8e812deb9f66 456 *
wim 0:8e812deb9f66 457 * @param reg Index of register
wim 0:8e812deb9f66 458 * @return data value from register
wim 0:8e812deb9f66 459 */
wim 0:8e812deb9f66 460 int16_t LM77::_readReg16(char reg) {
wim 0:8e812deb9f66 461
wim 0:8e812deb9f66 462 //Create a temporary buffer
wim 0:8e812deb9f66 463 char buf[2];
wim 0:8e812deb9f66 464
wim 0:8e812deb9f66 465 //Select the register
wim 0:8e812deb9f66 466 _i2c->write(_slaveAddress, &reg, 1, true);
wim 0:8e812deb9f66 467
wim 0:8e812deb9f66 468 //Read the 16-bit register
wim 0:8e812deb9f66 469 _i2c->read(_slaveAddress, buf, 2);
wim 0:8e812deb9f66 470
wim 0:8e812deb9f66 471 //Return the combined 16-bit value
wim 0:8e812deb9f66 472 return (buf[0] << 8) | buf[1];
wim 0:8e812deb9f66 473 }
wim 0:8e812deb9f66 474
wim 0:8e812deb9f66 475 /** Write 16 bit value to register
wim 0:8e812deb9f66 476 * Used for Critical temp threshold, Low and High temp threshold window and Hysteresis
wim 0:8e812deb9f66 477 *
wim 0:8e812deb9f66 478 * @param reg Index of register
wim 0:8e812deb9f66 479 * @param data value to write
wim 0:8e812deb9f66 480 */
wim 0:8e812deb9f66 481 void LM77::_writeReg16(char reg, int16_t data) {
wim 0:8e812deb9f66 482
wim 0:8e812deb9f66 483 //Create a temporary buffer
wim 0:8e812deb9f66 484 char buf[3];
wim 0:8e812deb9f66 485
wim 0:8e812deb9f66 486 //Load the register address and 16-bit data
wim 0:8e812deb9f66 487 buf[0] = reg;
wim 0:8e812deb9f66 488 buf[1] = data >> 8;
wim 0:8e812deb9f66 489 buf[2] = data;
wim 0:8e812deb9f66 490
wim 0:8e812deb9f66 491 //Write the data
wim 0:8e812deb9f66 492 _i2c->write(_slaveAddress, buf, 3);
wim 0:8e812deb9f66 493 }
wim 0:8e812deb9f66 494
wim 0:8e812deb9f66 495 /** Get Temperature as float in °Celsius
wim 0:8e812deb9f66 496 * Used for Critical temp threshold, Low and High temp threshold window and Hysteresis
wim 0:8e812deb9f66 497 *
wim 0:8e812deb9f66 498 * @param reg Index of register to read temp value
wim 0:8e812deb9f66 499 * @return float Temperature in °Celsius
wim 0:8e812deb9f66 500 */
wim 0:8e812deb9f66 501 float LM77::_readTempHelper(char reg) {
wim 0:8e812deb9f66 502
wim 0:8e812deb9f66 503 //Signed return value
wim 0:8e812deb9f66 504 int16_t value;
wim 0:8e812deb9f66 505
wim 0:8e812deb9f66 506 #if(1)
wim 0:8e812deb9f66 507 //Read the 9-bit raw temperature value in 0.5 degree resolution
wim 0:8e812deb9f66 508 value = _readReg16(reg) >> 3;
wim 0:8e812deb9f66 509 #else
wim 0:8e812deb9f66 510 int16_t readreg;
wim 0:8e812deb9f66 511
wim 0:8e812deb9f66 512 //Test neg temps
wim 0:8e812deb9f66 513 readreg = 0xFE70; //-25 degree
wim 0:8e812deb9f66 514 value = readreg >> 3;
wim 0:8e812deb9f66 515 #endif
wim 0:8e812deb9f66 516
wim 0:8e812deb9f66 517 //Sign extend negative numbers
wim 0:8e812deb9f66 518 if (value & (1 << 9))
wim 0:8e812deb9f66 519 value |= 0xFE00;
wim 0:8e812deb9f66 520
wim 0:8e812deb9f66 521 //Return the temperature in °C
wim 0:8e812deb9f66 522 return (float) value * 0.5f;
wim 0:8e812deb9f66 523 }
wim 0:8e812deb9f66 524
wim 0:8e812deb9f66 525
wim 0:8e812deb9f66 526 /** Set Temperature as float in °Celsius
wim 0:8e812deb9f66 527 * Used for Critical temp threshold, Low and High temp threshold window and Hysteresis
wim 0:8e812deb9f66 528 *
wim 0:8e812deb9f66 529 * @param reg Index of register to write temp value
wim 0:8e812deb9f66 530 * @param temp float Temperature value in °Celsius
wim 0:8e812deb9f66 531 */
wim 0:8e812deb9f66 532 void LM77::_writeTempHelper(char reg, float temp) {
wim 0:8e812deb9f66 533 //Signed value
wim 0:8e812deb9f66 534 int16_t value;
wim 0:8e812deb9f66 535
wim 0:8e812deb9f66 536 //Range limit temp
wim 0:8e812deb9f66 537 if (temp < -55.0)
wim 0:8e812deb9f66 538 temp = -55.0;
wim 0:8e812deb9f66 539 else if (temp > 125.0)
wim 0:8e812deb9f66 540 temp = 125.0;
wim 0:8e812deb9f66 541
wim 0:8e812deb9f66 542 //Extract and shift the signed integer
wim 0:8e812deb9f66 543 value = temp * 2.0f;
wim 0:8e812deb9f66 544 value <<= 3;
wim 0:8e812deb9f66 545
wim 0:8e812deb9f66 546 //Send the new value
wim 0:8e812deb9f66 547 _writeReg16(reg, value);
wim 0:8e812deb9f66 548 }