eunkyoung kim / LM75B

modify the write function for temperature update If you use update temperature, you modify the repeat condition when write function use - read16() -> m_I2C.write(m_Addr, &reg, 1); //stop condition - read16() -> m_I2C.write(m_Addr, &reg, 1,1); //repeat condition

Fork of LM75B by Neil Thiessen

LM75B.cpp@17:c62f1e2d721e, 2015-07-20 (annotated)

Committer:
eunkyoungkim
Date:
Mon Jul 20 09:36:26 2015 +0000
Revision:
17:c62f1e2d721e
Parent:
9:74b44a27fa40 
modify the Source code(in LM75B.cpp);  -  in LM75B::read16(char reg); write function is modified from stop condition to repeated condition for temperture value update;        m_I2C.write(m_Addr, &reg, 1) ->m_I2C.write(m_Addr, &reg,1,1);;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
neilt6 2:9ecc39b2ca70 1 /* LM75B Driver Library
neilt6 4:06676376766a 2 * Copyright (c) 2013 Neil Thiessen
neilt6 0:557a92280097 3 *
neilt6 3:9d68eed28bfb 4 * Licensed under the Apache License, Version 2.0 (the "License");
neilt6 3:9d68eed28bfb 5 * you may not use this file except in compliance with the License.
neilt6 3:9d68eed28bfb 6 * You may obtain a copy of the License at
neilt6 4:06676376766a 7 *
neilt6 4:06676376766a 8 * http://www.apache.org/licenses/LICENSE-2.0
neilt6 0:557a92280097 9 *
neilt6 3:9d68eed28bfb 10 * Unless required by applicable law or agreed to in writing, software
neilt6 3:9d68eed28bfb 11 * distributed under the License is distributed on an "AS IS" BASIS,
neilt6 3:9d68eed28bfb 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
neilt6 3:9d68eed28bfb 13 * See the License for the specific language governing permissions and
neilt6 3:9d68eed28bfb 14 * limitations under the License.
neilt6 0:557a92280097 15 */
neilt6 0:557a92280097 16
neilt6 0:557a92280097 17 #include "LM75B.h"
neilt6 0:557a92280097 18
eunkyoungkim 17:c62f1e2d721e 19 LM75B::LM75B(PinName sda, PinName scl, Address addr, int hz) : m_I2C(sda, scl)
neilt6 0:557a92280097 20 {
neilt6 0:557a92280097 21 //Set the internal device address
neilt6 8:2b797c309258 22 m_Addr = (int)addr;
eunkyoungkim 17:c62f1e2d721e 23 m_I2C.frequency(hz);
neilt6 0:557a92280097 24 }
neilt6 0:557a92280097 25
eunkyoungkim 17:c62f1e2d721e 26
neilt6 9:74b44a27fa40 27 bool LM75B::open(void)
neilt6 9:74b44a27fa40 28 {
neilt6 9:74b44a27fa40 29 //Probe for the LM75B using a Zero Length Transfer
neilt6 9:74b44a27fa40 30 if (!m_I2C.write(m_Addr, NULL, 0)) {
neilt6 9:74b44a27fa40 31 //Reset the device to default configuration
neilt6 9:74b44a27fa40 32 write8(REG_CONF, 0x00);
neilt6 9:74b44a27fa40 33 write16(REG_THYST, 0x4B00);
neilt6 9:74b44a27fa40 34 write16(REG_TOS, 0x5000);
neilt6 9:74b44a27fa40 35
neilt6 9:74b44a27fa40 36 //Return success
neilt6 9:74b44a27fa40 37 return true;
neilt6 9:74b44a27fa40 38 } else {
neilt6 9:74b44a27fa40 39 //Return failure
neilt6 9:74b44a27fa40 40 return false;
neilt6 9:74b44a27fa40 41 }
neilt6 9:74b44a27fa40 42 }
neilt6 9:74b44a27fa40 43
neilt6 8:2b797c309258 44 LM75B::PowerMode LM75B::powerMode(void)
neilt6 0:557a92280097 45 {
neilt6 0:557a92280097 46 //Read the 8-bit register value
neilt6 8:2b797c309258 47 char value = read8(REG_CONF);
neilt6 0:557a92280097 48
neilt6 0:557a92280097 49 //Return the status of the SHUTDOWN bit
neilt6 0:557a92280097 50 if (value & (1 << 0))
neilt6 2:9ecc39b2ca70 51 return POWER_SHUTDOWN;
neilt6 0:557a92280097 52 else
neilt6 2:9ecc39b2ca70 53 return POWER_NORMAL;
neilt6 0:557a92280097 54 }
neilt6 0:557a92280097 55
neilt6 8:2b797c309258 56 void LM75B::powerMode(PowerMode mode)
neilt6 0:557a92280097 57 {
neilt6 0:557a92280097 58 //Read the current 8-bit register value
neilt6 8:2b797c309258 59 char value = read8(REG_CONF);
neilt6 0:557a92280097 60
neilt6 0:557a92280097 61 //Set or clear the SHUTDOWN bit
neilt6 2:9ecc39b2ca70 62 if (mode == POWER_SHUTDOWN)
neilt6 0:557a92280097 63 value |= (1 << 0);
neilt6 0:557a92280097 64 else
neilt6 0:557a92280097 65 value &= ~(1 << 0);
neilt6 0:557a92280097 66
neilt6 0:557a92280097 67 //Write the value back out
neilt6 8:2b797c309258 68 write8(REG_CONF, value);
neilt6 0:557a92280097 69 }
neilt6 0:557a92280097 70
neilt6 8:2b797c309258 71 LM75B::OSMode LM75B::osMode(void)
neilt6 0:557a92280097 72 {
neilt6 0:557a92280097 73 //Read the 8-bit register value
neilt6 8:2b797c309258 74 char value = read8(REG_CONF);
neilt6 0:557a92280097 75
neilt6 0:557a92280097 76 //Return the status of the OS_COMP_INT bit
neilt6 0:557a92280097 77 if (value & (1 << 1))
neilt6 2:9ecc39b2ca70 78 return OS_INTERRUPT;
neilt6 0:557a92280097 79 else
neilt6 2:9ecc39b2ca70 80 return OS_COMPARATOR;
neilt6 0:557a92280097 81 }
neilt6 0:557a92280097 82
neilt6 8:2b797c309258 83 void LM75B::osMode(OSMode mode)
neilt6 0:557a92280097 84 {
neilt6 0:557a92280097 85 //Read the current 8-bit register value
neilt6 8:2b797c309258 86 char value = read8(REG_CONF);
neilt6 0:557a92280097 87
neilt6 0:557a92280097 88 //Set or clear the OS_COMP_INT bit
neilt6 2:9ecc39b2ca70 89 if (mode == OS_INTERRUPT)
neilt6 0:557a92280097 90 value |= (1 << 1);
neilt6 0:557a92280097 91 else
neilt6 0:557a92280097 92 value &= ~(1 << 1);
neilt6 0:557a92280097 93
neilt6 0:557a92280097 94 //Write the value back out
neilt6 8:2b797c309258 95 write8(REG_CONF, value);
neilt6 0:557a92280097 96 }
neilt6 0:557a92280097 97
neilt6 8:2b797c309258 98 LM75B::OSPolarity LM75B::osPolarity(void)
neilt6 0:557a92280097 99 {
neilt6 0:557a92280097 100 //Read the 8-bit register value
neilt6 8:2b797c309258 101 char value = read8(REG_CONF);
neilt6 0:557a92280097 102
neilt6 0:557a92280097 103 //Return the status of the OS_POL bit
neilt6 0:557a92280097 104 if (value & (1 << 2))
neilt6 2:9ecc39b2ca70 105 return OS_ACTIVE_HIGH;
neilt6 0:557a92280097 106 else
neilt6 2:9ecc39b2ca70 107 return OS_ACTIVE_LOW;
neilt6 0:557a92280097 108 }
neilt6 0:557a92280097 109
neilt6 8:2b797c309258 110 void LM75B::osPolarity(OSPolarity polarity)
neilt6 0:557a92280097 111 {
neilt6 0:557a92280097 112 //Read the current 8-bit register value
neilt6 8:2b797c309258 113 char value = read8(REG_CONF);
neilt6 0:557a92280097 114
neilt6 0:557a92280097 115 //Set or clear the OS_POL bit
neilt6 2:9ecc39b2ca70 116 if (polarity == OS_ACTIVE_HIGH)
neilt6 0:557a92280097 117 value |= (1 << 2);
neilt6 0:557a92280097 118 else
neilt6 0:557a92280097 119 value &= ~(1 << 2);
neilt6 0:557a92280097 120
neilt6 0:557a92280097 121 //Write the value back out
neilt6 8:2b797c309258 122 write8(REG_CONF, value);
neilt6 0:557a92280097 123 }
neilt6 0:557a92280097 124
neilt6 8:2b797c309258 125 LM75B::OSFaultQueue LM75B::osFaultQueue(void)
neilt6 0:557a92280097 126 {
neilt6 0:557a92280097 127 //Read the 8-bit register value
neilt6 8:2b797c309258 128 char value = read8(REG_CONF);
neilt6 0:557a92280097 129
neilt6 0:557a92280097 130 //Return the status of the OS_F_QUE bits
neilt6 0:557a92280097 131 if ((value & (1 << 3)) && (value & (1 << 4)))
neilt6 2:9ecc39b2ca70 132 return OS_FAULT_QUEUE_6;
neilt6 0:557a92280097 133 else if (!(value & (1 << 3)) && (value & (1 << 4)))
neilt6 2:9ecc39b2ca70 134 return OS_FAULT_QUEUE_4;
neilt6 0:557a92280097 135 else if ((value & (1 << 3)) && !(value & (1 << 4)))
neilt6 2:9ecc39b2ca70 136 return OS_FAULT_QUEUE_2;
neilt6 0:557a92280097 137 else
neilt6 2:9ecc39b2ca70 138 return OS_FAULT_QUEUE_1;
neilt6 0:557a92280097 139 }
neilt6 0:557a92280097 140
neilt6 8:2b797c309258 141 void LM75B::osFaultQueue(OSFaultQueue queue)
neilt6 0:557a92280097 142 {
neilt6 0:557a92280097 143 //Read the current 8-bit register value
neilt6 8:2b797c309258 144 char value = read8(REG_CONF);
neilt6 0:557a92280097 145
neilt6 0:557a92280097 146 //Clear the old OS_F_QUE bits
neilt6 0:557a92280097 147 value &= ~(3 << 3);
neilt6 0:557a92280097 148
neilt6 0:557a92280097 149 //Set the new OS_F_QUE bits
neilt6 2:9ecc39b2ca70 150 if (queue == OS_FAULT_QUEUE_2)
neilt6 0:557a92280097 151 value |= (1 << 3);
neilt6 2:9ecc39b2ca70 152 else if (queue == OS_FAULT_QUEUE_4)
neilt6 0:557a92280097 153 value |= (2 << 3);
neilt6 2:9ecc39b2ca70 154 else if (queue == OS_FAULT_QUEUE_6)
neilt6 0:557a92280097 155 value |= (3 << 3);
neilt6 0:557a92280097 156
neilt6 0:557a92280097 157 //Write the value back out
neilt6 8:2b797c309258 158 write8(REG_CONF, value);
neilt6 0:557a92280097 159 }
neilt6 0:557a92280097 160
neilt6 8:2b797c309258 161 float LM75B::alertTemp(void)
neilt6 0:557a92280097 162 {
neilt6 0:557a92280097 163 //Use the 9-bit helper to read the TOS register
neilt6 8:2b797c309258 164 return readAlertTempHelper(REG_TOS);
neilt6 0:557a92280097 165 }
neilt6 0:557a92280097 166
neilt6 8:2b797c309258 167 void LM75B::alertTemp(float temp)
neilt6 0:557a92280097 168 {
neilt6 0:557a92280097 169 //Use the 9-bit helper to write to the TOS register
neilt6 8:2b797c309258 170 return writeAlertTempHelper(REG_TOS, temp);
neilt6 0:557a92280097 171 }
neilt6 0:557a92280097 172
neilt6 8:2b797c309258 173 float LM75B::alertHyst(void)
neilt6 0:557a92280097 174 {
neilt6 0:557a92280097 175 //Use the 9-bit helper to read the THYST register
neilt6 8:2b797c309258 176 return readAlertTempHelper(REG_THYST);
neilt6 0:557a92280097 177 }
neilt6 0:557a92280097 178
neilt6 8:2b797c309258 179 void LM75B::alertHyst(float temp)
neilt6 0:557a92280097 180 {
neilt6 0:557a92280097 181 //Use the 9-bit helper to write to the THYST register
neilt6 8:2b797c309258 182 return writeAlertTempHelper(REG_THYST, temp);
neilt6 0:557a92280097 183 }
neilt6 0:557a92280097 184
neilt6 8:2b797c309258 185 float LM75B::temp(void)
neilt6 0:557a92280097 186 {
neilt6 0:557a92280097 187 //Signed return value
neilt6 0:557a92280097 188 short value;
neilt6 0:557a92280097 189
neilt6 0:557a92280097 190 //Read the 11-bit raw temperature value
neilt6 8:2b797c309258 191 value = read16(REG_TEMP) >> 5;
neilt6 0:557a92280097 192 //Sign extend negative numbers
neilt6 0:557a92280097 193 if (value & (1 << 10))
neilt6 0:557a92280097 194 value |= 0xFC00;
neilt6 0:557a92280097 195
neilt6 0:557a92280097 196 //Return the temperature in °C
eunkyoungkim 17:c62f1e2d721e 197 return value*0.125;
neilt6 0:557a92280097 198 }
neilt6 0:557a92280097 199
neilt6 8:2b797c309258 200 char LM75B::read8(char reg)
neilt6 0:557a92280097 201 {
neilt6 0:557a92280097 202 //Select the register
neilt6 8:2b797c309258 203 m_I2C.write(m_Addr, &reg, 1);
neilt6 0:557a92280097 204
neilt6 0:557a92280097 205 //Read the 8-bit register
neilt6 8:2b797c309258 206 m_I2C.read(m_Addr, &reg, 1);
neilt6 0:557a92280097 207
neilt6 0:557a92280097 208 //Return the byte
neilt6 0:557a92280097 209 return reg;
neilt6 0:557a92280097 210 }
neilt6 0:557a92280097 211
neilt6 8:2b797c309258 212 void LM75B::write8(char reg, char data)
neilt6 0:557a92280097 213 {
neilt6 0:557a92280097 214 //Create a temporary buffer
neilt6 0:557a92280097 215 char buff[2];
neilt6 0:557a92280097 216
neilt6 0:557a92280097 217 //Load the register address and 8-bit data
neilt6 0:557a92280097 218 buff[0] = reg;
neilt6 0:557a92280097 219 buff[1] = data;
neilt6 0:557a92280097 220
neilt6 0:557a92280097 221 //Write the data
neilt6 8:2b797c309258 222 m_I2C.write(m_Addr, buff, 2);
neilt6 0:557a92280097 223 }
neilt6 0:557a92280097 224
neilt6 8:2b797c309258 225 unsigned short LM75B::read16(char reg)
neilt6 0:557a92280097 226 {
neilt6 0:557a92280097 227 //Create a temporary buffer
neilt6 0:557a92280097 228 char buff[2];
neilt6 0:557a92280097 229
neilt6 0:557a92280097 230 //Select the register
eunkyoungkim 17:c62f1e2d721e 231 m_I2C.write(m_Addr, &reg, 1,1);
neilt6 0:557a92280097 232
neilt6 0:557a92280097 233 //Read the 16-bit register
neilt6 8:2b797c309258 234 m_I2C.read(m_Addr, buff, 2);
neilt6 0:557a92280097 235
neilt6 0:557a92280097 236 //Return the combined 16-bit value
neilt6 0:557a92280097 237 return (buff[0] << 8) | buff[1];
neilt6 0:557a92280097 238 }
neilt6 0:557a92280097 239
neilt6 8:2b797c309258 240 void LM75B::write16(char reg, unsigned short data)
neilt6 0:557a92280097 241 {
neilt6 0:557a92280097 242 //Create a temporary buffer
neilt6 0:557a92280097 243 char buff[3];
neilt6 0:557a92280097 244
neilt6 0:557a92280097 245 //Load the register address and 16-bit data
neilt6 0:557a92280097 246 buff[0] = reg;
neilt6 0:557a92280097 247 buff[1] = data >> 8;
neilt6 0:557a92280097 248 buff[2] = data;
neilt6 0:557a92280097 249
neilt6 0:557a92280097 250 //Write the data
neilt6 8:2b797c309258 251 m_I2C.write(m_Addr, buff, 3);
neilt6 0:557a92280097 252 }
neilt6 0:557a92280097 253
neilt6 8:2b797c309258 254 float LM75B::readAlertTempHelper(char reg)
neilt6 0:557a92280097 255 {
neilt6 0:557a92280097 256 //Signed return value
neilt6 0:557a92280097 257 short value;
neilt6 0:557a92280097 258
neilt6 0:557a92280097 259 //Read the 9-bit raw temperature value
neilt6 8:2b797c309258 260 value = read16(reg) >> 7;
neilt6 0:557a92280097 261
neilt6 0:557a92280097 262 //Sign extend negative numbers
neilt6 0:557a92280097 263 if (value & (1 << 8))
neilt6 0:557a92280097 264 value |= 0xFF00;
neilt6 0:557a92280097 265
neilt6 0:557a92280097 266 //Return the temperature in °C
neilt6 0:557a92280097 267 return value * 0.5;
neilt6 0:557a92280097 268 }
neilt6 0:557a92280097 269
neilt6 8:2b797c309258 270 void LM75B::writeAlertTempHelper(char reg, float temp)
neilt6 0:557a92280097 271 {
neilt6 0:557a92280097 272 //Range limit temp
neilt6 0:557a92280097 273 if (temp < -55.0)
neilt6 0:557a92280097 274 temp = -55.0;
neilt6 0:557a92280097 275 else if (temp > 125.0)
neilt6 0:557a92280097 276 temp = 125.0;
neilt6 0:557a92280097 277
neilt6 0:557a92280097 278 //Extract and shift the signed integer
neilt6 0:557a92280097 279 short value = temp * 2;
neilt6 0:557a92280097 280 value <<= 7;
neilt6 0:557a92280097 281
neilt6 0:557a92280097 282 //Send the new value
neilt6 8:2b797c309258 283 write16(reg, value);
neilt6 0:557a92280097 284 }