Cameron Haegle / DS1721

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

DS1721.cpp@3:3c182751e655, 2014-05-02 (annotated)

Committer:
chaegle
Date:
Fri May 02 17:08:05 2014 +0000
Revision:
3:3c182751e655
Parent:
2:22dbeccb82be 
Updated class constructors so as to set I2C bus frequency to 400KHz, in order to provide compatibility with FRDM-K64F platform.

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 3:3c182751e655 44 m_i2c.frequency(400000);
chaegle 2:22dbeccb82be 45 _resolution = RES_9_BIT;
chaegle 2:22dbeccb82be 46 _polarity = POLARITY_ACTIVE_HIGH;
chaegle 2:22dbeccb82be 47 _mode = CONV_FOREVER;
chaegle 1:4fd830a97574 48 _num_read = 1;
chaegle 1:4fd830a97574 49
chaegle 2:22dbeccb82be 50 //setConfig(_resolution | _polarity | _mode);
chaegle 1:4fd830a97574 51 }
chaegle 1:4fd830a97574 52
chaegle 2:22dbeccb82be 53 DS1721::DS1721(I2C &i2c, int resolution, int polarity, int mode, int addr)
chaegle 2:22dbeccb82be 54 : m_i2c(i2c) , _resolution(resolution) , _polarity(polarity) , _mode(mode) , m_addr(addr)
chaegle 3:3c182751e655 55 {
chaegle 3:3c182751e655 56 m_i2c.frequency(400000);
chaegle 1:4fd830a97574 57 _num_read = 1;
chaegle 2:22dbeccb82be 58 //setConfig(_resolution | _polarity | _mode);
chaegle 1:4fd830a97574 59 }
chaegle 1:4fd830a97574 60
chaegle 1:4fd830a97574 61 DS1721::~DS1721(void)
chaegle 1:4fd830a97574 62 {
chaegle 1:4fd830a97574 63 }
chaegle 1:4fd830a97574 64
chaegle 1:4fd830a97574 65 int DS1721::setConfig(int config)
chaegle 1:4fd830a97574 66 {
chaegle 1:4fd830a97574 67 char cmd[2];
chaegle 1:4fd830a97574 68 cmd[0] = CMD_ACCESS_CFG;
chaegle 1:4fd830a97574 69 cmd[1] = (config & 0xFF);
chaegle 2:22dbeccb82be 70
chaegle 2:22dbeccb82be 71 if(writeData(cmd, 2) != 0)
chaegle 1:4fd830a97574 72 {
chaegle 2:22dbeccb82be 73 return 1;
chaegle 1:4fd830a97574 74 }
chaegle 2:22dbeccb82be 75 return 0;
chaegle 1:4fd830a97574 76 }
chaegle 1:4fd830a97574 77
chaegle 1:4fd830a97574 78 int DS1721::getConfig(int* config)
chaegle 1:4fd830a97574 79 {
chaegle 1:4fd830a97574 80 char cmd[2];
chaegle 1:4fd830a97574 81
chaegle 1:4fd830a97574 82 cmd[0] = CMD_ACCESS_CFG; // 0xAC
chaegle 2:22dbeccb82be 83
chaegle 2:22dbeccb82be 84 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 85 {
chaegle 2:22dbeccb82be 86 return 1;
chaegle 1:4fd830a97574 87 }
chaegle 2:22dbeccb82be 88
chaegle 2:22dbeccb82be 89 if(readData(cmd, 1) != 0)
chaegle 1:4fd830a97574 90 {
chaegle 2:22dbeccb82be 91 return 1;
chaegle 1:4fd830a97574 92 }
chaegle 1:4fd830a97574 93 *config = cmd[0];
chaegle 2:22dbeccb82be 94 return 0;
chaegle 1:4fd830a97574 95 }
chaegle 1:4fd830a97574 96
chaegle 1:4fd830a97574 97
chaegle 2:22dbeccb82be 98 float DS1721::getTemp(void)
chaegle 1:4fd830a97574 99 {
chaegle 1:4fd830a97574 100 char cmd[3];
chaegle 1:4fd830a97574 101
chaegle 1:4fd830a97574 102 cmd[0] = CMD_READ_TEMP;
chaegle 1:4fd830a97574 103
chaegle 1:4fd830a97574 104 // if this is the first read, since power up, perform the read twice
chaegle 1:4fd830a97574 105 // this eliminate an erroneous initial read.
chaegle 1:4fd830a97574 106 do
chaegle 1:4fd830a97574 107 {
chaegle 2:22dbeccb82be 108 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 109 {
chaegle 2:22dbeccb82be 110 return 1;
chaegle 1:4fd830a97574 111 }
chaegle 2:22dbeccb82be 112
chaegle 1:4fd830a97574 113 // read 1 byte, ignoring fractional portion of temperature
chaegle 2:22dbeccb82be 114 if(readData(cmd, 2) != 0)
chaegle 1:4fd830a97574 115 {
chaegle 2:22dbeccb82be 116 return 1;
chaegle 1:4fd830a97574 117 }
chaegle 1:4fd830a97574 118 _num_read--;
chaegle 1:4fd830a97574 119 }while(_num_read);
chaegle 1:4fd830a97574 120
chaegle 1:4fd830a97574 121 _num_read = 1;
chaegle 1:4fd830a97574 122
chaegle 2:22dbeccb82be 123 return ((float)(cmd[1] + (cmd[0] << 8))/256);
chaegle 1:4fd830a97574 124 }
chaegle 1:4fd830a97574 125
chaegle 1:4fd830a97574 126 int DS1721::setPolarity(int polarity)
chaegle 1:4fd830a97574 127 {
chaegle 1:4fd830a97574 128 _polarity = polarity;
chaegle 2:22dbeccb82be 129 return setConfig(_resolution | _polarity | _mode);
chaegle 1:4fd830a97574 130 }
chaegle 1:4fd830a97574 131
chaegle 1:4fd830a97574 132 int DS1721::getPolarity(void)
chaegle 1:4fd830a97574 133 {
chaegle 2:22dbeccb82be 134 int config = 0;
chaegle 1:4fd830a97574 135 getConfig(&config);
chaegle 1:4fd830a97574 136 return ((config & (1<<1)) ? 1: 0);
chaegle 1:4fd830a97574 137 }
chaegle 1:4fd830a97574 138
chaegle 1:4fd830a97574 139 int DS1721::startConversion(void)
chaegle 1:4fd830a97574 140 {
chaegle 1:4fd830a97574 141 char cmd[1];
chaegle 1:4fd830a97574 142
chaegle 1:4fd830a97574 143 cmd[0] = CMD_START_CONVT; // 0x51
chaegle 1:4fd830a97574 144
chaegle 2:22dbeccb82be 145 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 146 {
chaegle 1:4fd830a97574 147 return 0;
chaegle 1:4fd830a97574 148 }
chaegle 1:4fd830a97574 149 return 1;
chaegle 1:4fd830a97574 150 }
chaegle 1:4fd830a97574 151
chaegle 1:4fd830a97574 152 int DS1721::stopConversion(void)
chaegle 1:4fd830a97574 153 {
chaegle 1:4fd830a97574 154 char cmd[1];
chaegle 1:4fd830a97574 155
chaegle 1:4fd830a97574 156 cmd[0] = CMD_STOP_CONVT; // 0x51
chaegle 1:4fd830a97574 157
chaegle 2:22dbeccb82be 158 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 159 {
chaegle 1:4fd830a97574 160 return 0;
chaegle 1:4fd830a97574 161 }
chaegle 1:4fd830a97574 162 return 1;
chaegle 1:4fd830a97574 163 }
chaegle 1:4fd830a97574 164
chaegle 2:22dbeccb82be 165 float DS1721::getLowSp(void)
chaegle 1:4fd830a97574 166 {
chaegle 1:4fd830a97574 167 char cmd[4];
chaegle 1:4fd830a97574 168
chaegle 1:4fd830a97574 169 cmd[0] = CMD_ACCESS_TL;
chaegle 2:22dbeccb82be 170
chaegle 2:22dbeccb82be 171 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 172 {
chaegle 1:4fd830a97574 173 //return FALSE;
chaegle 1:4fd830a97574 174 }
chaegle 1:4fd830a97574 175
chaegle 1:4fd830a97574 176 // read back TL msb & lsb bytes
chaegle 2:22dbeccb82be 177 if(readData(cmd, 2) != 0)
chaegle 1:4fd830a97574 178 {
chaegle 1:4fd830a97574 179 return 0;
chaegle 1:4fd830a97574 180 }
chaegle 2:22dbeccb82be 181
chaegle 2:22dbeccb82be 182 _tl = ((cmd[0] << 8) + cmd[1]);
chaegle 2:22dbeccb82be 183
chaegle 2:22dbeccb82be 184 return ((float)_tl/256);
chaegle 1:4fd830a97574 185 }
chaegle 1:4fd830a97574 186
chaegle 2:22dbeccb82be 187 int DS1721::setLowSp(float newSp)
chaegle 1:4fd830a97574 188 {
chaegle 1:4fd830a97574 189 char cmd[3];
chaegle 1:4fd830a97574 190
chaegle 2:22dbeccb82be 191 _tl = (newSp*256);
chaegle 1:4fd830a97574 192
chaegle 1:4fd830a97574 193 cmd[0] = CMD_ACCESS_TL;
chaegle 2:22dbeccb82be 194 cmd[1] = (char)(_tl >> 8); // temp MSB
chaegle 2:22dbeccb82be 195 cmd[2] = (char)(_tl & 0x00FF); // temp LSB (+/-0.5)
chaegle 2:22dbeccb82be 196
chaegle 2:22dbeccb82be 197 if(writeData(cmd, 3) != 0)
chaegle 1:4fd830a97574 198 {
chaegle 1:4fd830a97574 199 return 0;
chaegle 1:4fd830a97574 200 }
chaegle 1:4fd830a97574 201 return 1;
chaegle 1:4fd830a97574 202 }
chaegle 1:4fd830a97574 203
chaegle 2:22dbeccb82be 204 float DS1721::getHighSp(void)
chaegle 1:4fd830a97574 205 {
chaegle 1:4fd830a97574 206 char cmd[3];
chaegle 1:4fd830a97574 207
chaegle 1:4fd830a97574 208 cmd[0] = CMD_ACCESS_TH;
chaegle 2:22dbeccb82be 209
chaegle 2:22dbeccb82be 210 if(writeData(cmd, 1) != 0)
chaegle 1:4fd830a97574 211 {
chaegle 1:4fd830a97574 212 //return 0;
chaegle 1:4fd830a97574 213 }
chaegle 1:4fd830a97574 214 // read back TL msb & lsb bytes
chaegle 2:22dbeccb82be 215 if(readData(cmd, 2) != 0)
chaegle 1:4fd830a97574 216 {
chaegle 1:4fd830a97574 217 //return 0;
chaegle 1:4fd830a97574 218 }
chaegle 2:22dbeccb82be 219
chaegle 2:22dbeccb82be 220 _th = ((cmd[0] << 8) + cmd[1]);
chaegle 2:22dbeccb82be 221
chaegle 2:22dbeccb82be 222 return ((float)_th/256);
chaegle 1:4fd830a97574 223 }
chaegle 1:4fd830a97574 224
chaegle 2:22dbeccb82be 225 int DS1721::setHighSp(float newSp)
chaegle 1:4fd830a97574 226 {
chaegle 1:4fd830a97574 227 char cmd[3];
chaegle 1:4fd830a97574 228
chaegle 2:22dbeccb82be 229 _th = (newSp * 256);
chaegle 1:4fd830a97574 230
chaegle 1:4fd830a97574 231 cmd[0] = CMD_ACCESS_TH;
chaegle 2:22dbeccb82be 232 cmd[1] = (char)(_th >> 8); // setpoint MSB
chaegle 2:22dbeccb82be 233 cmd[2] = (char)(_th & 0x00FF); // setpoint LSB (+/-0.5)
chaegle 1:4fd830a97574 234
chaegle 2:22dbeccb82be 235 if(writeData(cmd, 3) != 0)
chaegle 1:4fd830a97574 236 {
chaegle 1:4fd830a97574 237 return 0;
chaegle 1:4fd830a97574 238 }
chaegle 1:4fd830a97574 239 return 1;
chaegle 1:4fd830a97574 240 }
chaegle 2:22dbeccb82be 241
chaegle 2:22dbeccb82be 242 float DS1721::temp_CtoF(float tempC)
chaegle 2:22dbeccb82be 243 {
chaegle 2:22dbeccb82be 244 return ((tempC * 1.8) + 32);
chaegle 2:22dbeccb82be 245 }
chaegle 2:22dbeccb82be 246
chaegle 2:22dbeccb82be 247 float DS1721::temp_FtoC(float tempF)
chaegle 2:22dbeccb82be 248 {
chaegle 2:22dbeccb82be 249 return ((tempF - 32)* 0.55);
chaegle 2:22dbeccb82be 250 }
chaegle 2:22dbeccb82be 251
chaegle 2:22dbeccb82be 252 int DS1721::writeData(char* data, int length)
chaegle 2:22dbeccb82be 253 {
chaegle 2:22dbeccb82be 254 return (m_i2c.write(m_addr, data, length));
chaegle 2:22dbeccb82be 255 }
chaegle 2:22dbeccb82be 256
chaegle 2:22dbeccb82be 257 int DS1721::readData(char* data, int length)
chaegle 2:22dbeccb82be 258 {
chaegle 2:22dbeccb82be 259 return (m_i2c.read(m_addr, data, length));
chaegle 2:22dbeccb82be 260 }