402 lines
9.1 KiB
C++
402 lines
9.1 KiB
C++
/*!
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* @file Adafruit_BMP183.cpp
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*
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* @mainpage Adafruit BMP183 Library
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*
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* @section intro_sec Introduction
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*
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* This is a library for the Adafruit BMP183 Barometric Pressure + Temp sensor
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*
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* Designed specifically to work with the Adafruit BMP183 Breakout
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* ----> http://www.adafruit.com/products/1900
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*
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* These sensors use SPI to communicate, 4 pins are required to
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* interface
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* Adafruit invests time and resources providing this open source code,
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* please support Adafruit and open-source hardware by purchasing
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* products from Adafruit!
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*
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* @section author Author
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*
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* Written by Limor Fried/Ladyada for Adafruit Industries.
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*
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* @section license License
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*
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* BSD license, all text above must be included in any redistribution
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*/
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#include "Adafruit_BMP183.h"
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#ifdef __AVR__
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#include <util/delay.h>
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#endif
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#define _delay_ms(t) \
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delay(t) //!< Delay for use in-between different lines/parts of code
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#include <SPI.h>
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/*!
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* @brief Instantiates a new Adafruit_BMP183 class using hardware SPI
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* @param SPICS
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* cs pin
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* @param *theSPI
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* optional SPI object, defaults to SPI
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*/
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Adafruit_BMP183::Adafruit_BMP183(int8_t SPICS, SPIClass *theSPI) {
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_cs = SPICS;
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_clk = _miso = _mosi = -1;
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_spi = theSPI;
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}
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/*!
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* @brief Instantiates a new Adafruit_BMP183 class using software SPI
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* @param SPICLK
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* SPI chip clock
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* @param SPIMISO
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* SPI MISO (Data to microcontroller from sensor)
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* @param SPIMOSI
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* SPI MOSI (Data from microcontroller to sensor)
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* @param SPICS
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* SPI CS PIN
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*/
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Adafruit_BMP183::Adafruit_BMP183(int8_t SPICLK, int8_t SPIMISO, int8_t SPIMOSI,
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int8_t SPICS) {
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_cs = SPICS;
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_clk = SPICLK;
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_miso = SPIMISO;
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_mosi = SPIMOSI;
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}
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/*!
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* @brief Setups the HW
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* @param mode
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* selected BMP183 mode
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* @return true if successful
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*/
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boolean Adafruit_BMP183::begin(bmp183_mode_t mode) {
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if (_clk == -1) {
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_spi->begin();
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_spi->setDataMode(SPI_MODE0);
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#ifdef __AVR__
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_spi->setClockDivider(SPI_CLOCK_DIV16);
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#endif
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#ifdef __SAM3X8E__
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_spi->setClockDivider(11); // 8-ish MHz (full! speed!)
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#endif
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} else {
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pinMode(_clk, OUTPUT);
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digitalWrite(_clk, HIGH);
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pinMode(_mosi, OUTPUT);
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digitalWrite(_mosi, HIGH);
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pinMode(_miso, INPUT);
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}
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pinMode(_cs, OUTPUT);
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digitalWrite(_cs, HIGH);
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/* Mode boundary check */
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if ((mode > BMP183_MODE_ULTRAHIGHRES) || (mode < 0)) {
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mode = BMP183_MODE_ULTRAHIGHRES;
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}
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/* Set the mode indicator */
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oversampling = mode;
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if (read8(0xD0) != 0x55)
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return false;
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/* Read calibration data */
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ac1 = read16(BMP183_REGISTER_CAL_AC1);
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ac2 = read16(BMP183_REGISTER_CAL_AC2);
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ac3 = read16(BMP183_REGISTER_CAL_AC3);
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ac4 = read16(BMP183_REGISTER_CAL_AC4);
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ac5 = read16(BMP183_REGISTER_CAL_AC5);
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ac6 = read16(BMP183_REGISTER_CAL_AC6);
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b1 = read16(BMP183_REGISTER_CAL_B1);
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b2 = read16(BMP183_REGISTER_CAL_B2);
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mb = read16(BMP183_REGISTER_CAL_MB);
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mc = read16(BMP183_REGISTER_CAL_MC);
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md = read16(BMP183_REGISTER_CAL_MD);
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#if (BMP183_DEBUG == 1)
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Serial.print("ac1 = ");
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Serial.println(ac1, DEC);
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Serial.print("ac2 = ");
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Serial.println(ac2, DEC);
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Serial.print("ac3 = ");
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Serial.println(ac3, DEC);
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Serial.print("ac4 = ");
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Serial.println(ac4, DEC);
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Serial.print("ac5 = ");
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Serial.println(ac5, DEC);
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Serial.print("ac6 = ");
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Serial.println(ac6, DEC);
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Serial.print("b1 = ");
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Serial.println(b1, DEC);
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Serial.print("b2 = ");
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Serial.println(b2, DEC);
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Serial.print("mb = ");
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Serial.println(mb, DEC);
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Serial.print("mc = ");
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Serial.println(mc, DEC);
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Serial.print("md = ");
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Serial.println(md, DEC);
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#endif
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return true;
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}
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/*!
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* @brief Reads raw temperature reading
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* @return Raw Temeperature from BMP183_REGISTER_TEMPDATA.
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*/
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uint16_t Adafruit_BMP183::readRawTemperature() {
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write8(BMP183_REGISTER_CONTROL, BMP183_REGISTER_READTEMPCMD);
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_delay_ms(5);
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#if BMP183_DEBUG == 1
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Serial.print("Raw temp: ");
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Serial.println(read16(BMP183_REGISTER_TEMPDATA));
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#endif
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return read16(BMP183_REGISTER_TEMPDATA);
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}
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/*!
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* @brief Reads raw pressure reading
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* @return Raw Pressure from BMP183_REGISTER_PRESSUREDATA
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*/
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uint32_t Adafruit_BMP183::readRawPressure() {
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uint32_t raw;
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write8(BMP183_REGISTER_CONTROL,
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BMP183_REGISTER_READPRESSURECMD + (oversampling << 6));
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if (oversampling == BMP183_MODE_ULTRALOWPOWER)
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_delay_ms(5);
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else if (oversampling == BMP183_MODE_STANDARD)
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_delay_ms(8);
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else if (oversampling == BMP183_MODE_HIGHRES)
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_delay_ms(14);
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else
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_delay_ms(26);
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raw = read16(BMP183_REGISTER_PRESSUREDATA);
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raw <<= 8;
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raw |= read8(BMP183_REGISTER_PRESSUREDATA + 2);
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raw >>= (8 - oversampling);
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/* this pull broke stuff, look at it later?
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if (oversampling==0) {
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raw <<= 8;
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raw |= read8(BMP183_PRESSUREDATA+2);
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raw >>= (8 - oversampling);
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}
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*/
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#if BMP183_DEBUG == 1
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Serial.print("Raw pressure: ");
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Serial.println(raw);
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#endif
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return raw;
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}
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/*!
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* @brief Gets the compensated pressure level in hPa
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* @return Pressure value in hPa
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*/
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int32_t Adafruit_BMP183::getPressure() {
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int32_t UT, UP, B3, B5, B6, X1, X2, X3, p;
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uint32_t B4, B7;
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UT = readRawTemperature();
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UP = readRawPressure();
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#if BMP183_DEBUG == 1
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// use datasheet numbers!
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UT = 27898;
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UP = 23843;
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ac6 = 23153;
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ac5 = 32757;
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mc = -8711;
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md = 2868;
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b1 = 6190;
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b2 = 4;
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ac3 = -14383;
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ac2 = -72;
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ac1 = 408;
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ac4 = 32741;
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oversampling = 0;
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#endif
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// do temperature calculations
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X1 = (UT - (int32_t)(ac6)) * ((int32_t)(ac5)) / pow(2, 15);
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X2 = ((int32_t)mc * pow(2, 11)) / (X1 + (int32_t)md);
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B5 = X1 + X2;
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#if BMP183_DEBUG == 1
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Serial.print("X1 = ");
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Serial.println(X1);
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Serial.print("X2 = ");
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Serial.println(X2);
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Serial.print("B5 = ");
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Serial.println(B5);
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#endif
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// do pressure calcs
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B6 = B5 - 4000;
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X1 = ((int32_t)b2 * ((B6 * B6) >> 12)) >> 11;
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X2 = ((int32_t)ac2 * B6) >> 11;
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X3 = X1 + X2;
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B3 = ((((int32_t)ac1 * 4 + X3) << oversampling) + 2) / 4;
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#if BMP183_DEBUG == 1
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Serial.print("B6 = ");
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Serial.println(B6);
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Serial.print("X1 = ");
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Serial.println(X1);
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Serial.print("X2 = ");
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Serial.println(X2);
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Serial.print("B3 = ");
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Serial.println(B3);
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#endif
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X1 = ((int32_t)ac3 * B6) >> 13;
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X2 = ((int32_t)b1 * ((B6 * B6) >> 12)) >> 16;
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X3 = ((X1 + X2) + 2) >> 2;
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B4 = ((uint32_t)ac4 * (uint32_t)(X3 + 32768)) >> 15;
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B7 = ((uint32_t)UP - B3) * (uint32_t)(50000UL >> oversampling);
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#if BMP183_DEBUG == 1
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Serial.print("X1 = ");
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Serial.println(X1);
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Serial.print("X2 = ");
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Serial.println(X2);
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Serial.print("B4 = ");
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Serial.println(B4);
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Serial.print("B7 = ");
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Serial.println(B7);
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#endif
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if (B7 < 0x80000000) {
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p = (B7 * 2) / B4;
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} else {
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p = (B7 / B4) * 2;
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}
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X1 = (p >> 8) * (p >> 8);
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X1 = (X1 * 3038) >> 16;
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X2 = (-7357 * p) >> 16;
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#if BMP183_DEBUG == 1
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Serial.print("p = ");
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Serial.println(p);
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Serial.print("X1 = ");
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Serial.println(X1);
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Serial.print("X2 = ");
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Serial.println(X2);
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#endif
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p = p + ((X1 + X2 + (int32_t)3791) >> 4);
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#if BMP183_DEBUG == 1
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Serial.print("p = ");
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Serial.println(p);
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#endif
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return p;
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}
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/*!
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* @brief Reads the temperatures in Celsius degrees
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* @return temperature in Celsius
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*/
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float Adafruit_BMP183::getTemperature() {
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int32_t UT, X1, X2, B5; // following ds convention
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float temp;
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UT = readRawTemperature();
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#if BMP183_DEBUG == 1
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// use datasheet numbers!
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UT = 27898;
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ac6 = 23153;
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ac5 = 32757;
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mc = -8711;
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md = 2868;
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#endif
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// step 1
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X1 = (UT - (int32_t)ac6) * ((int32_t)ac5) / pow(2, 15);
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X2 = ((int32_t)mc * pow(2, 11)) / (X1 + (int32_t)md);
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B5 = X1 + X2;
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temp = (B5 + 8) / pow(2, 4);
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temp /= 10;
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return temp;
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}
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/*!
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* @brief Reads the altitude based on provided sea level pressure
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* @param sealevelPressure
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* pressure in hPa
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* @return altitude value in meters
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*/
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float Adafruit_BMP183::getAltitude(float sealevelPressure) {
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float altitude;
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float pressure = getPressure(); // in Si units for Pascal
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pressure /= 100;
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altitude = 44330 * (1.0 - pow(pressure / sealevelPressure, 0.1903));
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return altitude;
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}
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/*********************************************************************/
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uint8_t Adafruit_BMP183::SPIxfer(uint8_t x) {
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if (_clk == -1) {
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return _spi->transfer(x);
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} else {
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// Serial.println("Software SPI");
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uint8_t reply = 0;
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for (int i = 7; i >= 0; i--) {
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reply <<= 1;
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digitalWrite(_clk, LOW);
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digitalWrite(_mosi, x & (1 << i));
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digitalWrite(_clk, HIGH);
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if (digitalRead(_miso))
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reply |= 1;
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}
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return reply;
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}
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}
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uint8_t Adafruit_BMP183::read8(uint8_t reg) {
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uint8_t value;
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digitalWrite(_cs, LOW);
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SPIxfer(0x80 | reg);
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value = SPIxfer(0x00);
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digitalWrite(_cs, HIGH);
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return value;
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}
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uint16_t Adafruit_BMP183::read16(uint8_t reg) {
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uint16_t value;
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digitalWrite(_cs, LOW);
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SPIxfer(0x80 | reg);
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value = SPIxfer(0x00);
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value <<= 8;
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value |= SPIxfer(0x00);
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digitalWrite(_cs, HIGH);
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return value;
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}
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void Adafruit_BMP183::write8(uint8_t reg, uint8_t value) {
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digitalWrite(_cs, LOW);
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SPIxfer(reg & 0x7F);
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SPIxfer(value);
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digitalWrite(_cs, HIGH);
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}
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