Juergen M / TMP007

Drivber for Ti's TMP007 Infrared Thermopile Sensor with Integrated Math Engine

src/TMP007.cpp@0:a1ed9ce625d4, 2016-06-05 (annotated)

Committer:
messi1
Date:
Sun Jun 05 19:38:48 2016 +0000
Revision:
0:a1ed9ce625d4
Child:
1:93710a3abf0a
Init version of TMP007 which is based on TMP006 class with a lot of rewriting

Who changed what in which revision?

UserRevisionLine numberNew contents of line
messi1 0:a1ed9ce625d4 1 #include <math.h>
messi1 0:a1ed9ce625d4 2 #include "TMP007.h"
messi1 0:a1ed9ce625d4 3
messi1 0:a1ed9ce625d4 4 TMP007::TMP007(PinName sda, PinName scl, int addr)
messi1 0:a1ed9ce625d4 5 :_i2cPort(sda, scl),
messi1 0:a1ed9ce625d4 6 _addr(addr<<1)
messi1 0:a1ed9ce625d4 7 {}
messi1 0:a1ed9ce625d4 8
messi1 0:a1ed9ce625d4 9 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 10 bool TMP007::writeWord(const uint8_t reg, const uint16_t word)
messi1 0:a1ed9ce625d4 11 {
messi1 0:a1ed9ce625d4 12 const char cmd[] = { reg, word & 0xff, (word&0xff00)>>8 };
messi1 0:a1ed9ce625d4 13
messi1 0:a1ed9ce625d4 14 if( 0 == _i2cPort.write(_addr, cmd, 3 ))
messi1 0:a1ed9ce625d4 15 return true;
messi1 0:a1ed9ce625d4 16 else
messi1 0:a1ed9ce625d4 17 return false;
messi1 0:a1ed9ce625d4 18 }
messi1 0:a1ed9ce625d4 19
messi1 0:a1ed9ce625d4 20 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 21 uint16_t TMP007::readWord(const uint8_t reg)
messi1 0:a1ed9ce625d4 22 {
messi1 0:a1ed9ce625d4 23 uint16_t res = 0;
messi1 0:a1ed9ce625d4 24 char data[] = {0, 0};
messi1 0:a1ed9ce625d4 25 const char cmd = reg;
messi1 0:a1ed9ce625d4 26
messi1 0:a1ed9ce625d4 27 _i2cPort.write(_addr, &cmd, 1);
messi1 0:a1ed9ce625d4 28 _i2cPort.read(_addr, data, 2);
messi1 0:a1ed9ce625d4 29 res = data[1]<<8 & data[0];
messi1 0:a1ed9ce625d4 30
messi1 0:a1ed9ce625d4 31 return res;
messi1 0:a1ed9ce625d4 32 }
messi1 0:a1ed9ce625d4 33
messi1 0:a1ed9ce625d4 34 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 35 void TMP007::writeConfig(const uint16_t value)
messi1 0:a1ed9ce625d4 36 {
messi1 0:a1ed9ce625d4 37 writeWord(TMP007_CONFIG, value);
messi1 0:a1ed9ce625d4 38 }
messi1 0:a1ed9ce625d4 39
messi1 0:a1ed9ce625d4 40 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 41 uint16_t TMP007::readConfig()
messi1 0:a1ed9ce625d4 42 {
messi1 0:a1ed9ce625d4 43 uint16_t res = readWord(TMP007_CONFIG);
messi1 0:a1ed9ce625d4 44 return res;
messi1 0:a1ed9ce625d4 45 }
messi1 0:a1ed9ce625d4 46
messi1 0:a1ed9ce625d4 47 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 48 uint16_t TMP007::readStatus()
messi1 0:a1ed9ce625d4 49 {
messi1 0:a1ed9ce625d4 50 return readWord(TMP007_STATUS);
messi1 0:a1ed9ce625d4 51 }
messi1 0:a1ed9ce625d4 52
messi1 0:a1ed9ce625d4 53 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 54 /** TMP007 Config method.
messi1 0:a1ed9ce625d4 55 * Used for configuring the sensor with desired samples.
messi1 0:a1ed9ce625d4 56 */
messi1 0:a1ed9ce625d4 57 void TMP007::setSamples(uint16_t samples)
messi1 0:a1ed9ce625d4 58 {
messi1 0:a1ed9ce625d4 59 char data[2];
messi1 0:a1ed9ce625d4 60
messi1 0:a1ed9ce625d4 61 data[0] = TMP007_CONFIG;
messi1 0:a1ed9ce625d4 62 data[1] = samples | TMP007_CFG_MODEON | TMP007_CFG_ALRTEN;
messi1 0:a1ed9ce625d4 63
messi1 0:a1ed9ce625d4 64 _i2cPort.write( _addr, data, 1 );
messi1 0:a1ed9ce625d4 65 }
messi1 0:a1ed9ce625d4 66
messi1 0:a1ed9ce625d4 67 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 68 /** TMP007 Read Raw Temperature method.
messi1 0:a1ed9ce625d4 69 * Used for getting the raw data off the chip.
messi1 0:a1ed9ce625d4 70 */
messi1 0:a1ed9ce625d4 71 uint16_t TMP007::readRawLocalTemperature()
messi1 0:a1ed9ce625d4 72 {
messi1 0:a1ed9ce625d4 73 int16_t raw = 0;
messi1 0:a1ed9ce625d4 74 char reg = TMP007_LOCAL_TEMP;
messi1 0:a1ed9ce625d4 75 char data[2];
messi1 0:a1ed9ce625d4 76
messi1 0:a1ed9ce625d4 77 _i2cPort.write(_addr, &reg, 1);
messi1 0:a1ed9ce625d4 78 _i2cPort.read(_addr, data, 2);
messi1 0:a1ed9ce625d4 79
messi1 0:a1ed9ce625d4 80 raw = (data[0] << 8) | data[1] ;
messi1 0:a1ed9ce625d4 81
messi1 0:a1ed9ce625d4 82 raw >>= 2;
messi1 0:a1ed9ce625d4 83 return raw;
messi1 0:a1ed9ce625d4 84 }
messi1 0:a1ed9ce625d4 85
messi1 0:a1ed9ce625d4 86 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 87 /** TMP007 Read Raw Voltage method.
messi1 0:a1ed9ce625d4 88 * Used for reading the raw voltage from the thermopile.
messi1 0:a1ed9ce625d4 89 */
messi1 0:a1ed9ce625d4 90 uint16_t TMP007::readRawSensorVoltage()
messi1 0:a1ed9ce625d4 91 {
messi1 0:a1ed9ce625d4 92 char reg=TMP007_SENSOR_VOLT;
messi1 0:a1ed9ce625d4 93 char data[2];
messi1 0:a1ed9ce625d4 94
messi1 0:a1ed9ce625d4 95 _i2cPort.write(_addr, &reg, 1);
messi1 0:a1ed9ce625d4 96 _i2cPort.read(_addr, data, 2);
messi1 0:a1ed9ce625d4 97
messi1 0:a1ed9ce625d4 98 int16_t raw = (data[0] << 8) | data[1] ;
messi1 0:a1ed9ce625d4 99
messi1 0:a1ed9ce625d4 100 return raw;
messi1 0:a1ed9ce625d4 101 }
messi1 0:a1ed9ce625d4 102
messi1 0:a1ed9ce625d4 103 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 104 /** TMP007 Read Object Temperature(C) method.
messi1 0:a1ed9ce625d4 105 * Used for calculating the object temperature in celcius.
messi1 0:a1ed9ce625d4 106 */
messi1 0:a1ed9ce625d4 107 double TMP007::readObjTempC()
messi1 0:a1ed9ce625d4 108 {
messi1 0:a1ed9ce625d4 109 double Tdie = readRawLocalTemperature();
messi1 0:a1ed9ce625d4 110 double Vobj = readRawSensorVoltage();
messi1 0:a1ed9ce625d4 111 Vobj *= 156.25; // 156.25 nV per LSB
messi1 0:a1ed9ce625d4 112 Vobj /= 1000000000; // nV -> V
messi1 0:a1ed9ce625d4 113 Tdie *= 0.03125; // convert to celsius
messi1 0:a1ed9ce625d4 114 Tdie += 273.15; // convert to kelvin
messi1 0:a1ed9ce625d4 115
messi1 0:a1ed9ce625d4 116 // Equations for calculating temperature found in section 7.3.4 in the user guide
messi1 0:a1ed9ce625d4 117 double tdie_tref = Tdie - TMP007_TREF;
messi1 0:a1ed9ce625d4 118 double S = (1 + TMP007_A1*tdie_tref +
messi1 0:a1ed9ce625d4 119 TMP007_A2*tdie_tref*tdie_tref);
messi1 0:a1ed9ce625d4 120 S *= TMP007_S0;
messi1 0:a1ed9ce625d4 121 S /= 10000000;
messi1 0:a1ed9ce625d4 122 S /= 10000000;
messi1 0:a1ed9ce625d4 123
messi1 0:a1ed9ce625d4 124 double Vos = TMP007_B0 + TMP007_B1*tdie_tref + TMP007_B2*tdie_tref*tdie_tref;
messi1 0:a1ed9ce625d4 125
messi1 0:a1ed9ce625d4 126 double fVobj = (Vobj - Vos) + TMP007_C2*(Vobj-Vos)*(Vobj-Vos);
messi1 0:a1ed9ce625d4 127
messi1 0:a1ed9ce625d4 128 double Tobj = sqrt(sqrt(Tdie * Tdie * Tdie * Tdie + fVobj/S));
messi1 0:a1ed9ce625d4 129
messi1 0:a1ed9ce625d4 130 Tobj -= 273.15; // Kelvin -> *C
messi1 0:a1ed9ce625d4 131 return Tobj;
messi1 0:a1ed9ce625d4 132 }
messi1 0:a1ed9ce625d4 133
messi1 0:a1ed9ce625d4 134 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 135 /** TMP007 Read Object Temperature(F) method.
messi1 0:a1ed9ce625d4 136 * Used for calculating the object temperature in fahrenheit.
messi1 0:a1ed9ce625d4 137 */
messi1 0:a1ed9ce625d4 138 double TMP007::readObjTempF()
messi1 0:a1ed9ce625d4 139 {
messi1 0:a1ed9ce625d4 140 double Tobj = readObjTempC();
messi1 0:a1ed9ce625d4 141 Tobj = Tobj * 9.0/5.0 + 32.0; // convert to fahrenheit
messi1 0:a1ed9ce625d4 142 return Tobj;
messi1 0:a1ed9ce625d4 143 }
messi1 0:a1ed9ce625d4 144
messi1 0:a1ed9ce625d4 145 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 146 /** TMP007 Read Die Temperature(C) method.
messi1 0:a1ed9ce625d4 147 * Used for calculating the die temperature in celcius.
messi1 0:a1ed9ce625d4 148 */
messi1 0:a1ed9ce625d4 149 double TMP007::readDieTempC()
messi1 0:a1ed9ce625d4 150 {
messi1 0:a1ed9ce625d4 151 double Tdie = readRawLocalTemperature();
messi1 0:a1ed9ce625d4 152 Tdie *= 0.03125; // convert to celsius
messi1 0:a1ed9ce625d4 153 return Tdie;
messi1 0:a1ed9ce625d4 154 }
messi1 0:a1ed9ce625d4 155
messi1 0:a1ed9ce625d4 156 //--------------------------------------------------------------------------------
messi1 0:a1ed9ce625d4 157 /** TMP007 Read Die Temperature(F) method.
messi1 0:a1ed9ce625d4 158 * Used for calculating the die temperature in fahrenheit.
messi1 0:a1ed9ce625d4 159 */
messi1 0:a1ed9ce625d4 160 double TMP007::readDieTempF()
messi1 0:a1ed9ce625d4 161 {
messi1 0:a1ed9ce625d4 162 double Tdie = readDieTempC();
messi1 0:a1ed9ce625d4 163 Tdie = Tdie * 9.0/5.0 + 32.0; // convert to fahrenheit
messi1 0:a1ed9ce625d4 164 return Tdie;
messi1 0:a1ed9ce625d4 165 }