RHT03.h

00001 /* mbed RHT03 Library
00002   Copyright (c) 2011, sford, http://mbed.org
00003   Modifications by Tristan Hughes
00004  
00005   Permission is hereby granted, free of charge, to any person obtaining a copy
00006   of this software and associated documnetation files (the "Software"), to deal
00007   in the Software without restriction, including without limitation the rights
00008   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00009   copies of the Software, and to permit persons to  whom the Software is
00010   furished to do so, subject to the following conditions:
00011  
00012   The above copyright notice and this permission notice shall be included in
00013   all copies or substantial portions of the Software.
00014  
00015   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00016   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00017   FITNESS OR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00018   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00019   LIABILITY WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00020   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00021   THE SOFTWARE.
00022  */
00023 
00024 #ifndef MBED_RHT03_H
00025 #define MBED_RHT03_H
00026 
00027 #include "mbed.h"
00028 
00029 
00030 #define RHT03_ERROR_VALUE -99.5
00031 
00032 typedef enum {
00033     RHT_ERROR_NONE = 0,
00034     RHT_BUS_HUNG,
00035     RHT_ERROR_NOT_PRESENT,
00036     RHT_ERROR_ACK_TOO_LONG,
00037     RHT_ERROR_SYNC_TIMEOUT,
00038     RHT_ERROR_DATA_TIMEOUT,
00039     RHT_ERROR_CHECKSUM,
00040     RHT_ERROR_TOO_QUICK
00041 } RHT03_ERROR;
00042 
00043 /** RHT03 interface class for reading data from the sensor */
00044 class RHT03
00045 {
00046 private:
00047     time_t  _lastReadTime;
00048     PinName _data;
00049     float   _lastHumidity;
00050     float   _lastTemperature;
00051 public:
00052     /** Configure data pin
00053       * @param Data The data pin the RHT03 is attached to
00054       */
00055     RHT03(PinName Data);
00056     ~RHT03();
00057     /** Reads data from the RHT03
00058       * @return error type or successful read
00059       */
00060     RHT03_ERROR readData(void);
00061     /** Gives current humidity value
00062       * @return humidity value
00063       */
00064     float getHumidity();
00065     /** Gives current temperature value
00066       * @return temperature value
00067       */
00068     float getTemperatureC();
00069     void clockReset();
00070 };
00071 
00072 #endif /*_RHT03_H_*/