Diff: sht75.h

Revision:

0:f401474a3e96

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sht75.h	Wed Oct 27 15:27:38 2010 +0000
@@ -0,0 +1,75 @@
+/* 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
+
+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