File content as of revision 1:20aa2d4a28bf:

/* mbed Sensiron SHT7x temperature and humidity sensor library
*
* Sensiron data at http://www.sensirion.com/en/01_humidity_sensors/06_humidity_sensor_sht75.htm
*
* Copyright (c) Ian Molesworth October 2010
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to use
* copy or modify the software for private or non-commercial purposes only. 
*
* 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.
*/


#ifndef SHT75_H
#define SHT75_H

#include "mbed.h"

const float C1= -4.0;              // for 12 Bit humi
const float C2= +0.0405;           // for 12 Bit humi
const float C3= -0.0000028;        // for 12 Bit hum
const float TL= -39.61;             // 3v 14 bit 
const float T1= +0.01;             // for 14 Bit @ 5V
const float T2= +0.00008;          // for 14 Bit @ 5V

/** SHT7x class
*
* Example:
* @code
* //initialise the device read temperature ticks, read humidity ticks and then
* calculate the liniarised humidity value.
* #include "mbed.h"
* #include "SHT7X.h"
00035  * 
00036  * Servo myservo(p21);
00037  * 
00038  * int main() {
00039  *     while(1) {
00040  *         for(int i=0; i<100; i++) {
00041  *             myservo = i/100.0;
00042  *             wait(0.01);
00043  *         }
00044  *         for(int i=100; i>0; i--) {
00045  *             myservo = i/100.0;
00046  *             wait(0.01);
00047  *         }
00048  *     }
00049  * }
00050  * @endcode
00051  */
class SHT75 
    {
    public:
     /** Create an SHT object connected to the specified Digital pins
      *
      * @param pclock digital pin to use as clock
      * @param pdata digital pin to use as data bus ( bidirectional ) 
      */
        SHT75(PinName pclock, PinName pdata): _clock(pclock), _data(pdata) {};
     /** read the temperature ticks value 14 bit resolution
      *
      * @param int *temp pointer to an integer to hold the tick value
      * @returns boolean true if read acknowledges
      */
        bool readTempTicks(int* temp);
     /** read the humidity ticks value 12 bit resolution
      *
      * @param int *temp pointer to an integer to hold the tick value
      * @returns boolean true if read acknowledges
      */
        bool readHumidityTicks(int* temp);
     /** start up reset
      *
      * call to resync or abort current operation.
      * worth calling every now and then to make sure your system is not hung.
      */
        void reset(void);
        void softReset(void);
        int  readStatus(void);
  
    private:  
        DigitalInOut _data;
        DigitalOut _clock;
        
        void start(void);
        int read(char);
        bool write(char);
    };

#endif