Cameron Haegle / DS1721

Library for the DS1721, 2-Wire Digital Thermometer and Thermostat from Dallas Semiconductor (Maxim Integrated)

DS1721.cpp@2:22dbeccb82be, 2013-07-30 (annotated)

Committer:
chaegle
Date:
Tue Jul 30 20:23:07 2013 +0000
Revision:
2:22dbeccb82be
Parent:
1:4fd830a97574
Child:
3:3c182751e655
initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
chaegle 2:22dbeccb82be 1 /*
chaegle 2:22dbeccb82be 2 * @file DS1721.cpp
chaegle 2:22dbeccb82be 3 * @author Cameron Haegle
chaegle 2:22dbeccb82be 4 *
chaegle 2:22dbeccb82be 5 * @section LICENSE
chaegle 2:22dbeccb82be 6 *
chaegle 2:22dbeccb82be 7 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
chaegle 2:22dbeccb82be 8 * and associated documentation files (the "Software"), to deal in the Software without restriction,
chaegle 2:22dbeccb82be 9 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
chaegle 2:22dbeccb82be 10 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
chaegle 2:22dbeccb82be 11 * furnished to do so, subject to the following conditions:
chaegle 2:22dbeccb82be 12 *
chaegle 2:22dbeccb82be 13 * The above copyright notice and this permission notice shall be included in all copies or
chaegle 2:22dbeccb82be 14 * substantial portions of the Software.
chaegle 2:22dbeccb82be 15 *
chaegle 2:22dbeccb82be 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
chaegle 2:22dbeccb82be 17 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
chaegle 2:22dbeccb82be 18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
chaegle 2:22dbeccb82be 19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
chaegle 2:22dbeccb82be 20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
chaegle 2:22dbeccb82be 21 *
chaegle 2:22dbeccb82be 22 * @section DESCRIPTION
chaegle 2:22dbeccb82be 23 *
chaegle 2:22dbeccb82be 24 * Library for the DS1721, 2-Wire Digital Thermometer and Thermostat, from Maxim Semiconductor
chaegle 2:22dbeccb82be 25 * (www.maiximintegrated.com).
chaegle 2:22dbeccb82be 26 *
chaegle 2:22dbeccb82be 27 * @section LIMITATIONS
chaegle 1:4fd830a97574 28 *
chaegle 2:22dbeccb82be 29 * This library was not written with for use with the mbed-RTOS, as the I2C read/write calls are
chaegle 2:22dbeccb82be 30 * not thread safe.
chaegle 1:4fd830a97574 31 *
chaegle 2:22dbeccb82be 32 * ChangeLog
chaegle 2:22dbeccb82be 33 * 07/30/2013
chaegle 2:22dbeccb82be 34 * -
chaegle 2:22dbeccb82be 35 */
chaegle 1:4fd830a97574 36
chaegle 1:4fd830a97574 37
chaegle 2:22dbeccb82be 38
chaegle 2:22dbeccb82be 39 #include "DS1721.h"
chaegle 2:22dbeccb82be 40
chaegle 1:4fd830a97574 41
chaegle 2:22dbeccb82be 42 DS1721::DS1721(I2C &i2c, int addr) : m_i2c(i2c) , m_addr(addr)
chaegle 1:4fd830a97574 43 {
chaegle 2:22dbeccb82be 44 _resolution = RES_9_BIT;
chaegle 2:22dbeccb82be 45 _polarity = POLARITY_ACTIVE_HIGH;
chaegle 2:22dbeccb82be 46 _mode = CONV_FOREVER;
chaegle 1:4fd830a97574 47 _num_read = 1;
chaegle 1:4fd830a97574 48
chaegle 2:22dbeccb82be 49 //setConfig(_resolution | _polarity | _mode);
chaegle 1:4fd830a97574 50 }
chaegle 1:4fd830a97574 51
chaegle 2:22dbeccb82be 52 DS1721::DS1721(I2C &i2c, int resolution, int polarity, int mode, int addr)
chaegle 2:22dbeccb82be 53 : m_i2c(i2c) , _resolution(resolution) , _polarity(polarity) , _mode(mode) , m_addr(addr)
chaegle 1:4fd830a97574 54 {
chaegle 1:4fd830a97574 55 _num_read = 1;
chaegle 2:22dbeccb82be 56 //setConfig(_resolution | _polarity | _mode);
chaegle 1:4fd830a97574 57 }
chaegle 1:4fd830a97574 58
chaegle 1:4fd830a97574 59 DS1721::~DS1721(void)
chaegle 1:4fd830a97574 60 {
chaegle 1:4fd830a97574 61 }
chaegle 1:4fd830a97574 62
chaegle 1:4fd830a97574 63 int DS1721::setConfig(int config)
chaegle 1:4fd830a97574 64 {
chaegle 1:4fd830a97574 65 char cmd[2];
chaegle 1:4fd830a97574 66 cmd[0] = CMD_ACCESS_CFG;
chaegle 1:4fd830a97574 67 cmd[1] = (config & 0xFF);
chaegle 2:22dbeccb82be 68
chaegle 2:22dbeccb82be 69 if(writeData(cmd, 2) != 0)
chaegle 1:4fd830a97574 70 {
chaegle 2:22dbeccb82be 71 return 1;
chaegle 1:4fd830a97574 72 }
chaegle 2:22dbeccb82be 73 return 0;
chaegle 1:4fd830a97574 74 }
chaegle 1:4fd830a97574 75
chaegle 1:4fd830a97574 76 int DS1721::getConfig(int* config)
chaegle 1:4fd830a97574 77 {
chaegle 1:4fd830a97574 78 char cmd[2];
chaegle 1:4fd830a97574 79
chaegle 1:4fd830a97574 80 cmd[0] = CMD_ACCESS_CFG; // 0xAC
chaegle 2:22dbeccb82be 81
chaegle 2:22dbeccb82be 82 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 83 {
chaegle 2:22dbeccb82be 84 return 1;
chaegle 1:4fd830a97574 85 }
chaegle 2:22dbeccb82be 86
chaegle 2:22dbeccb82be 87 if(readData(cmd, 1) != 0)
chaegle 1:4fd830a97574 88 {
chaegle 2:22dbeccb82be 89 return 1;
chaegle 1:4fd830a97574 90 }
chaegle 1:4fd830a97574 91 *config = cmd[0];
chaegle 2:22dbeccb82be 92 return 0;
chaegle 1:4fd830a97574 93 }
chaegle 1:4fd830a97574 94
chaegle 1:4fd830a97574 95
chaegle 2:22dbeccb82be 96 float DS1721::getTemp(void)
chaegle 1:4fd830a97574 97 {
chaegle 1:4fd830a97574 98 char cmd[3];
chaegle 1:4fd830a97574 99
chaegle 1:4fd830a97574 100 cmd[0] = CMD_READ_TEMP;
chaegle 1:4fd830a97574 101
chaegle 1:4fd830a97574 102 // if this is the first read, since power up, perform the read twice
chaegle 1:4fd830a97574 103 // this eliminate an erroneous initial read.
chaegle 1:4fd830a97574 104 do
chaegle 1:4fd830a97574 105 {
chaegle 2:22dbeccb82be 106 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 107 {
chaegle 2:22dbeccb82be 108 return 1;
chaegle 1:4fd830a97574 109 }
chaegle 2:22dbeccb82be 110
chaegle 1:4fd830a97574 111 // read 1 byte, ignoring fractional portion of temperature
chaegle 2:22dbeccb82be 112 if(readData(cmd, 2) != 0)
chaegle 1:4fd830a97574 113 {
chaegle 2:22dbeccb82be 114 return 1;
chaegle 1:4fd830a97574 115 }
chaegle 1:4fd830a97574 116 _num_read--;
chaegle 1:4fd830a97574 117 }while(_num_read);
chaegle 1:4fd830a97574 118
chaegle 1:4fd830a97574 119 _num_read = 1;
chaegle 1:4fd830a97574 120
chaegle 2:22dbeccb82be 121 return ((float)(cmd[1] + (cmd[0] << 8))/256);
chaegle 1:4fd830a97574 122 }
chaegle 1:4fd830a97574 123
chaegle 1:4fd830a97574 124 int DS1721::setPolarity(int polarity)
chaegle 1:4fd830a97574 125 {
chaegle 1:4fd830a97574 126 _polarity = polarity;
chaegle 2:22dbeccb82be 127 return setConfig(_resolution | _polarity | _mode);
chaegle 1:4fd830a97574 128 }
chaegle 1:4fd830a97574 129
chaegle 1:4fd830a97574 130 int DS1721::getPolarity(void)
chaegle 1:4fd830a97574 131 {
chaegle 2:22dbeccb82be 132 int config = 0;
chaegle 1:4fd830a97574 133 getConfig(&config);
chaegle 1:4fd830a97574 134 return ((config & (1<<1)) ? 1: 0);
chaegle 1:4fd830a97574 135 }
chaegle 1:4fd830a97574 136
chaegle 1:4fd830a97574 137 int DS1721::startConversion(void)
chaegle 1:4fd830a97574 138 {
chaegle 1:4fd830a97574 139 char cmd[1];
chaegle 1:4fd830a97574 140
chaegle 1:4fd830a97574 141 cmd[0] = CMD_START_CONVT; // 0x51
chaegle 1:4fd830a97574 142
chaegle 2:22dbeccb82be 143 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 144 {
chaegle 1:4fd830a97574 145 return 0;
chaegle 1:4fd830a97574 146 }
chaegle 1:4fd830a97574 147 return 1;
chaegle 1:4fd830a97574 148 }
chaegle 1:4fd830a97574 149
chaegle 1:4fd830a97574 150 int DS1721::stopConversion(void)
chaegle 1:4fd830a97574 151 {
chaegle 1:4fd830a97574 152 char cmd[1];
chaegle 1:4fd830a97574 153
chaegle 1:4fd830a97574 154 cmd[0] = CMD_STOP_CONVT; // 0x51
chaegle 1:4fd830a97574 155
chaegle 2:22dbeccb82be 156 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 157 {
chaegle 1:4fd830a97574 158 return 0;
chaegle 1:4fd830a97574 159 }
chaegle 1:4fd830a97574 160 return 1;
chaegle 1:4fd830a97574 161 }
chaegle 1:4fd830a97574 162
chaegle 2:22dbeccb82be 163 float DS1721::getLowSp(void)
chaegle 1:4fd830a97574 164 {
chaegle 1:4fd830a97574 165 char cmd[4];
chaegle 1:4fd830a97574 166
chaegle 1:4fd830a97574 167 cmd[0] = CMD_ACCESS_TL;
chaegle 2:22dbeccb82be 168
chaegle 2:22dbeccb82be 169 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 170 {
chaegle 1:4fd830a97574 171 //return FALSE;
chaegle 1:4fd830a97574 172 }
chaegle 1:4fd830a97574 173
chaegle 1:4fd830a97574 174 // read back TL msb & lsb bytes
chaegle 2:22dbeccb82be 175 if(readData(cmd, 2) != 0)
chaegle 1:4fd830a97574 176 {
chaegle 1:4fd830a97574 177 return 0;
chaegle 1:4fd830a97574 178 }
chaegle 2:22dbeccb82be 179
chaegle 2:22dbeccb82be 180 _tl = ((cmd[0] << 8) + cmd[1]);
chaegle 2:22dbeccb82be 181
chaegle 2:22dbeccb82be 182 return ((float)_tl/256);
chaegle 1:4fd830a97574 183 }
chaegle 1:4fd830a97574 184
chaegle 2:22dbeccb82be 185 int DS1721::setLowSp(float newSp)
chaegle 1:4fd830a97574 186 {
chaegle 1:4fd830a97574 187 char cmd[3];
chaegle 1:4fd830a97574 188
chaegle 2:22dbeccb82be 189 _tl = (newSp*256);
chaegle 1:4fd830a97574 190
chaegle 1:4fd830a97574 191 cmd[0] = CMD_ACCESS_TL;
chaegle 2:22dbeccb82be 192 cmd[1] = (char)(_tl >> 8); // temp MSB
chaegle 2:22dbeccb82be 193 cmd[2] = (char)(_tl & 0x00FF); // temp LSB (+/-0.5)
chaegle 2:22dbeccb82be 194
chaegle 2:22dbeccb82be 195 if(writeData(cmd, 3) != 0)
chaegle 1:4fd830a97574 196 {
chaegle 1:4fd830a97574 197 return 0;
chaegle 1:4fd830a97574 198 }
chaegle 1:4fd830a97574 199 return 1;
chaegle 1:4fd830a97574 200 }
chaegle 1:4fd830a97574 201
chaegle 2:22dbeccb82be 202 float DS1721::getHighSp(void)
chaegle 1:4fd830a97574 203 {
chaegle 1:4fd830a97574 204 char cmd[3];
chaegle 1:4fd830a97574 205
chaegle 1:4fd830a97574 206 cmd[0] = CMD_ACCESS_TH;
chaegle 2:22dbeccb82be 207
chaegle 2:22dbeccb82be 208 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 209 {
chaegle 1:4fd830a97574 210 //return 0;
chaegle 1:4fd830a97574 211 }
chaegle 1:4fd830a97574 212 // read back TL msb & lsb bytes
chaegle 2:22dbeccb82be 213 if(readData(cmd, 2) != 0)
chaegle 1:4fd830a97574 214 {
chaegle 1:4fd830a97574 215 //return 0;
chaegle 1:4fd830a97574 216 }
chaegle 2:22dbeccb82be 217
chaegle 2:22dbeccb82be 218 _th = ((cmd[0] << 8) + cmd[1]);
chaegle 2:22dbeccb82be 219
chaegle 2:22dbeccb82be 220 return ((float)_th/256);
chaegle 1:4fd830a97574 221 }
chaegle 1:4fd830a97574 222
chaegle 2:22dbeccb82be 223 int DS1721::setHighSp(float newSp)
chaegle 1:4fd830a97574 224 {
chaegle 1:4fd830a97574 225 char cmd[3];
chaegle 1:4fd830a97574 226
chaegle 2:22dbeccb82be 227 _th = (newSp * 256);
chaegle 1:4fd830a97574 228
chaegle 1:4fd830a97574 229 cmd[0] = CMD_ACCESS_TH;
chaegle 2:22dbeccb82be 230 cmd[1] = (char)(_th >> 8); // setpoint MSB
chaegle 2:22dbeccb82be 231 cmd[2] = (char)(_th & 0x00FF); // setpoint LSB (+/-0.5)
chaegle 1:4fd830a97574 232
chaegle 2:22dbeccb82be 233 if(writeData(cmd, 3) != 0)
chaegle 1:4fd830a97574 234 {
chaegle 1:4fd830a97574 235 return 0;
chaegle 1:4fd830a97574 236 }
chaegle 1:4fd830a97574 237 return 1;
chaegle 1:4fd830a97574 238 }
chaegle 2:22dbeccb82be 239
chaegle 2:22dbeccb82be 240 float DS1721::temp_CtoF(float tempC)
chaegle 2:22dbeccb82be 241 {
chaegle 2:22dbeccb82be 242 return ((tempC * 1.8) + 32);
chaegle 2:22dbeccb82be 243 }
chaegle 2:22dbeccb82be 244
chaegle 2:22dbeccb82be 245 float DS1721::temp_FtoC(float tempF)
chaegle 2:22dbeccb82be 246 {
chaegle 2:22dbeccb82be 247 return ((tempF - 32)* 0.55);
chaegle 2:22dbeccb82be 248 }
chaegle 2:22dbeccb82be 249
chaegle 2:22dbeccb82be 250 int DS1721::writeData(char* data, int length)
chaegle 2:22dbeccb82be 251 {
chaegle 2:22dbeccb82be 252 return (m_i2c.write(m_addr, data, length));
chaegle 2:22dbeccb82be 253 }
chaegle 2:22dbeccb82be 254
chaegle 2:22dbeccb82be 255 int DS1721::readData(char* data, int length)
chaegle 2:22dbeccb82be 256 {
chaegle 2:22dbeccb82be 257 return (m_i2c.read(m_addr, data, length));
chaegle 2:22dbeccb82be 258 }