Adafruit_SGP30.h

00001 /*!
00002  * @file Adafruit_SGP30.h
00003  *
00004  * This is the documentation for Adafruit's SGP30 driver for the
00005  * Arduino platform.  It is designed specifically to work with the
00006  * Adafruit SGP30 breakout: http://www.adafruit.com/products/3709
00007  *
00008  * These sensors use I2C to communicate, 2 pins (SCL+SDA) are required
00009  * to interface with the breakout.
00010  *
00011  * Adafruit invests time and resources providing this open source code,
00012  * please support Adafruit and open-source hardware by purchasing
00013  * products from Adafruit!
00014  *
00015  * Written by Ladyada for Adafruit Industries.
00016  *
00017  * BSD license, all text here must be included in any redistribution.
00018  *
00019 */
00020 
00021 #include "mbed.h"
00022 
00023 // the i2c address
00024 #define SGP30_I2CADDR_DEFAULT 0x58     ///< SGP30 has only one I2C address
00025 
00026 // commands and constants
00027 #define SGP30_FEATURESET       0x0020  ///< The required set for this library
00028 #define SGP30_CRC8_POLYNOMIAL  0x31    ///< Seed for SGP30's CRC polynomial
00029 #define SGP30_CRC8_INIT        0xFF    ///< Init value for CRC
00030 #define SGP30_WORD_LEN         2       ///< 2 bytes per word
00031 
00032 /**************************************************************************/
00033 /*!  Class that stores state and functions for interacting with SGP30 Gas Sensor */
00034 /**************************************************************************/
00035 class Adafruit_SGP30  {
00036  public:
00037   Adafruit_SGP30(PinName sda, PinName scl);
00038   bool begin();
00039   bool IAQinit(void);
00040   bool IAQmeasure(void);
00041 
00042   bool getIAQBaseline(uint16_t *eco2_base, uint16_t *tvoc_base);
00043   bool setIAQBaseline(uint16_t eco2_base, uint16_t tvoc_base);
00044   bool getIAQRaw(uint16_t *H2_raw, uint16_t *Eth_raw);
00045 
00046   /**
00047    * The last measurement of the IAQ-calculated Total Volatile Organic Compounds in ppb. This value is set when you call {@link IAQmeasure()}
00048    */
00049   uint16_t TVOC;
00050 
00051   /**
00052    * The last measurement of the IAQ-calculated equivalent CO2 in ppm. This value is set when you call {@link IAQmeasure()}
00053    */
00054   uint16_t eCO2;
00055 
00056   /**
00057    * The 48-bit serial number, this value is set when you call {@link begin()}
00058    */
00059   uint16_t serialnumber[3];
00060  private:
00061   I2C _i2c;
00062   int _i2caddr;
00063 
00064   void write(uint8_t address, uint8_t *data, uint8_t n);
00065   void read(uint8_t address, uint8_t *data, uint8_t n);
00066   bool readWordFromCommand(uint8_t command[], uint8_t commandLength, uint16_t delay, uint16_t *readdata = NULL, uint8_t readlen = 0);
00067   uint8_t generateCRC(uint8_t data[], uint8_t datalen);
00068 };