Library to work with the MS5611 pressure sensors. Forked from the MS5607 library
Dependents: MS5611Example Atlas HC-06_MPU9250_F303K_Stream
Fork of MS5607 by
Diff: MS5611Base.h
- Revision:
- 1:847720b736ea
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MS5611Base.h Tue Jun 24 05:44:17 2014 +0000 @@ -0,0 +1,128 @@ +/* +Copyright (c) 2012, Senio Networks, Inc. + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. +*/ + +/* MS5611 Modifications +Aerodyne Labs +Matthew Nelson - 2014 +This library was originally the MS5607 library. It has been modified to +to be used the MS5611 Pressure sensor +*/ + +#ifndef MS5611_BASE_H +#define MS5611_BASE_H + +class MS5611Base { +public: + void printCoefficients() { + printf("%d, %d, %d, %d, %d, %d \r\n", c1, c2, c3, c4, c5, c6); + } + + int getRawTemperature() { + return readADC(ADC_D2 | OSR_4096); + } + + int getRawPressure() { + return readADC(ADC_D1 | OSR_4096); + } + + float getTemperature() { + int dT = getRawTemperature() - (c5 << 8); + int temp = 2000 + ((dT * c6) >> 23); + + // 2nd order temperature compensation + if (temp < 2000) { + int t2 = (int64_t) dT * dT >> 31; + temp -= t2; + } + + return float(temp) / 100; + } + + float getPressure() { + int dT = getRawTemperature() - (c5 << 8); + int temp = 2000 + ((dT * c6) >> 23); + int64_t off = ((int64_t) c2 << 16) + ((int64_t) dT * c4 >> 7); + int64_t sens = ((int64_t) c1 << 15) + ((int64_t) dT * c3 >> 8); + + // 2nd order temperature compensation + if (temp < 2000) { + int64_t off2 = (int64_t) 5 * (temp - 2000) * (temp - 2000) >> 1; + int64_t sens2 = (int64_t) 5 * (temp - 2000) * (temp - 2000) >> 2; + if (temp < -1500) { + off2 += (int64_t) 7 * (temp + 1500) * (temp + 1500); + sens2 += (int64_t) 11 * (temp + 1500) * (temp + 1500) >> 1; + } + off -= off2; + sens -= sens2; + } + + return float((((int64_t) getRawPressure() * sens >> 21) - off) >> 15); + } + + float getAltitude(int presssure = 0) { + return toAltitude(presssure ? presssure : (int) getPressure()); + } + +protected: + int32_t c1, c2, c3, c4, c5, c6; + + enum { + RESET = 0x1E, + ADC_READ = 0x00, + ADC_CONV = 0x40, + ADC_D1 = 0x00, + ADC_D2 = 0x10, + OSR_256 = 0x00, + OSR_512 = 0x02, + OSR_1024 = 0x04, + OSR_2048 = 0x06, + OSR_4096 = 0x08, + PROM_READ = 0xA0 + }; + + virtual void writeCommand(int command, int ms = 0) = 0; + virtual int readPROM(int address) = 0; + virtual int readADC(int command) = 0; + + void init() { + writeCommand(RESET, 3); + c1 = readPROM(1); + c2 = readPROM(2); + c3 = readPROM(3); + c4 = readPROM(4); + c5 = readPROM(5); + c6 = readPROM(6); + } + + float toAltitude(int pressure) { + // Ref. 29124-AltimeterAppNote1.pdf + const float R = 287.052; // specific gas constant R*/M0 + const float g = 9.80665; // standard gravity + const float t_grad = 0.0065; // gradient of temperature + const float t0 = 273.15 + 15; // temperature at 0 altitude + const float p0 = 101325; // pressure at 0 altitude + + return t0 / t_grad * (1 - exp((t_grad * R / g) * log(pressure / p0))); + } +}; + +#endif \ No newline at end of file