Hiroshi Yamaguchi / MS5607

MS5607 Parallax micro altimeter module interfaces (I2C & SPI)

Dependents:   MS5607Example Vertex_Integration_4 Time_MS5607_Pressure Time_MS5607_Temperature ... more

MS5607Base.h@0:5760862143d1, 2012-07-03 (annotated)

Committer:
yamaguch
Date:
Tue Jul 03 08:57:57 2012 +0000
Revision:
0:5760862143d1
0.92

Who changed what in which revision?

UserRevisionLine numberNew contents of line
yamaguch 0:5760862143d1 1 /*
yamaguch 0:5760862143d1 2 Copyright (c) 2012, Senio Networks, Inc.
yamaguch 0:5760862143d1 3
yamaguch 0:5760862143d1 4 Permission is hereby granted, free of charge, to any person obtaining a copy
yamaguch 0:5760862143d1 5 of this software and associated documentation files (the "Software"), to deal
yamaguch 0:5760862143d1 6 in the Software without restriction, including without limitation the rights
yamaguch 0:5760862143d1 7 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
yamaguch 0:5760862143d1 8 copies of the Software, and to permit persons to whom the Software is
yamaguch 0:5760862143d1 9 furnished to do so, subject to the following conditions:
yamaguch 0:5760862143d1 10
yamaguch 0:5760862143d1 11 The above copyright notice and this permission notice shall be included in
yamaguch 0:5760862143d1 12 all copies or substantial portions of the Software.
yamaguch 0:5760862143d1 13
yamaguch 0:5760862143d1 14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
yamaguch 0:5760862143d1 15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
yamaguch 0:5760862143d1 16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
yamaguch 0:5760862143d1 17 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
yamaguch 0:5760862143d1 18 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
yamaguch 0:5760862143d1 19 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
yamaguch 0:5760862143d1 20 THE SOFTWARE.
yamaguch 0:5760862143d1 21 */
yamaguch 0:5760862143d1 22
yamaguch 0:5760862143d1 23 #ifndef MS5607_BASE_H
yamaguch 0:5760862143d1 24 #define MS5607_BASE_H
yamaguch 0:5760862143d1 25
yamaguch 0:5760862143d1 26 class MS5607Base {
yamaguch 0:5760862143d1 27 public:
yamaguch 0:5760862143d1 28 void printCoefficients() {
yamaguch 0:5760862143d1 29 printf("%d, %d, %d, %d, %d, %d\n", c1, c2, c3, c4, c5, c6);
yamaguch 0:5760862143d1 30 }
yamaguch 0:5760862143d1 31
yamaguch 0:5760862143d1 32 int getRawTemperature() {
yamaguch 0:5760862143d1 33 return readADC(ADC_D2 | OSR_4096);
yamaguch 0:5760862143d1 34 }
yamaguch 0:5760862143d1 35
yamaguch 0:5760862143d1 36 int getRawPressure() {
yamaguch 0:5760862143d1 37 return readADC(ADC_D1 | OSR_4096);
yamaguch 0:5760862143d1 38 }
yamaguch 0:5760862143d1 39
yamaguch 0:5760862143d1 40 float getTemperature() {
yamaguch 0:5760862143d1 41 int dT = getRawTemperature() - (c5 << 8);
yamaguch 0:5760862143d1 42 int temp = 2000 + ((dT * c6) >> 23);
yamaguch 0:5760862143d1 43
yamaguch 0:5760862143d1 44 // 2nd order temperature compensation
yamaguch 0:5760862143d1 45 if (temp < 2000) {
yamaguch 0:5760862143d1 46 int t2 = (int64_t) dT * dT >> 31;
yamaguch 0:5760862143d1 47 temp -= t2;
yamaguch 0:5760862143d1 48 }
yamaguch 0:5760862143d1 49
yamaguch 0:5760862143d1 50 return float(temp) / 100;
yamaguch 0:5760862143d1 51 }
yamaguch 0:5760862143d1 52
yamaguch 0:5760862143d1 53 float getPressure() {
yamaguch 0:5760862143d1 54 int dT = getRawTemperature() - (c5 << 8);
yamaguch 0:5760862143d1 55 int temp = 2000 + ((dT * c6) >> 23);
yamaguch 0:5760862143d1 56 int64_t off = ((int64_t) c2 << 17) + ((int64_t) dT * c4 >> 6);
yamaguch 0:5760862143d1 57 int64_t sens = ((int64_t) c1 << 16) + ((int64_t) dT * c3 >> 7);
yamaguch 0:5760862143d1 58
yamaguch 0:5760862143d1 59 // 2nd order temperature compensation
yamaguch 0:5760862143d1 60 if (temp < 2000) {
yamaguch 0:5760862143d1 61 int64_t off2 = (int64_t) 61 * (temp - 2000) * (temp - 2000) >> 4;
yamaguch 0:5760862143d1 62 int64_t sens2 = (int64_t) 2 * (temp - 2000) * (temp - 2000);
yamaguch 0:5760862143d1 63 if (temp < -1500) {
yamaguch 0:5760862143d1 64 off2 += (int64_t) 15 * (temp + 1500) * (temp + 1500);
yamaguch 0:5760862143d1 65 sens2 += (int64_t) 8 * (temp + 1500) * (temp + 1500);
yamaguch 0:5760862143d1 66 }
yamaguch 0:5760862143d1 67 off -= off2;
yamaguch 0:5760862143d1 68 sens -= sens2;
yamaguch 0:5760862143d1 69 }
yamaguch 0:5760862143d1 70
yamaguch 0:5760862143d1 71 return float((((int64_t) getRawPressure() * sens >> 21) - off) >> 15);
yamaguch 0:5760862143d1 72 }
yamaguch 0:5760862143d1 73
yamaguch 0:5760862143d1 74 float getAltitude(int presssure = 0) {
yamaguch 0:5760862143d1 75 return toAltitude(presssure ? presssure : (int) getPressure());
yamaguch 0:5760862143d1 76 }
yamaguch 0:5760862143d1 77
yamaguch 0:5760862143d1 78 protected:
yamaguch 0:5760862143d1 79 int32_t c1, c2, c3, c4, c5, c6;
yamaguch 0:5760862143d1 80
yamaguch 0:5760862143d1 81 enum {
yamaguch 0:5760862143d1 82 RESET = 0x1E,
yamaguch 0:5760862143d1 83 ADC_READ = 0x00,
yamaguch 0:5760862143d1 84 ADC_CONV = 0x40,
yamaguch 0:5760862143d1 85 ADC_D1 = 0x00,
yamaguch 0:5760862143d1 86 ADC_D2 = 0x10,
yamaguch 0:5760862143d1 87 OSR_256 = 0x00,
yamaguch 0:5760862143d1 88 OSR_512 = 0x02,
yamaguch 0:5760862143d1 89 OSR_1024 = 0x04,
yamaguch 0:5760862143d1 90 OSR_2048 = 0x06,
yamaguch 0:5760862143d1 91 OSR_4096 = 0x08,
yamaguch 0:5760862143d1 92 PROM_READ = 0xA0
yamaguch 0:5760862143d1 93 };
yamaguch 0:5760862143d1 94
yamaguch 0:5760862143d1 95 virtual void writeCommand(int command, int ms = 0) = 0;
yamaguch 0:5760862143d1 96 virtual int readPROM(int address) = 0;
yamaguch 0:5760862143d1 97 virtual int readADC(int command) = 0;
yamaguch 0:5760862143d1 98
yamaguch 0:5760862143d1 99 void init() {
yamaguch 0:5760862143d1 100 writeCommand(RESET, 3);
yamaguch 0:5760862143d1 101 c1 = readPROM(1);
yamaguch 0:5760862143d1 102 c2 = readPROM(2);
yamaguch 0:5760862143d1 103 c3 = readPROM(3);
yamaguch 0:5760862143d1 104 c4 = readPROM(4);
yamaguch 0:5760862143d1 105 c5 = readPROM(5);
yamaguch 0:5760862143d1 106 c6 = readPROM(6);
yamaguch 0:5760862143d1 107 }
yamaguch 0:5760862143d1 108
yamaguch 0:5760862143d1 109 float toAltitude(int pressure) {
yamaguch 0:5760862143d1 110 // Ref. 29124-AltimeterAppNote1.pdf
yamaguch 0:5760862143d1 111 const float R = 287.052; // specific gas constant R*/M0
yamaguch 0:5760862143d1 112 const float g = 9.80665; // standard gravity
yamaguch 0:5760862143d1 113 const float t_grad = 0.0065; // gradient of temperature
yamaguch 0:5760862143d1 114 const float t0 = 273.15 + 15; // temperature at 0 altitude
yamaguch 0:5760862143d1 115 const float p0 = 101325; // pressure at 0 altitude
yamaguch 0:5760862143d1 116
yamaguch 0:5760862143d1 117 return t0 / t_grad * (1 - exp((t_grad * R / g) * log(pressure / p0)));
yamaguch 0:5760862143d1 118 }
yamaguch 0:5760862143d1 119 };
yamaguch 0:5760862143d1 120
yamaguch 0:5760862143d1 121 #endif