Diff: DHT22.h

Revision:

0:42ffca439fcc

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DHT22.h	Thu Mar 29 06:14:07 2012 +0000
@@ -0,0 +1,84 @@
+/* mbed DHT22 Library
+ * Copyright (c) 2011, sford, http://mbed.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documnetation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to  whom the Software is
+ * furished to do so, subject to the following conditions:
+ *
+ * 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 OR 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 MBED_DHT22_H
+#define MBED_DHT22_H
+
+#include "mbed.h"
+
+/**
+ * Currently supports DHT22 (SparkFun Electronics)
+ * Humidity and Temperature Sensor
+ *
+ * Features:
+ *  >   3.3-6V Input
+ *  >   1-1.5mA measuring current
+ *  >   40-50uA standby current
+ *  >   Humidity from 0-100% RH
+ *  >   -40 - 80 degrees C  temperature range
+ *  >   +-2% RH accuracy
+ *  >   +-0.5 degrees C
+ *
+ * Usages
+ * #include "DHT22.h"
+ *
+ * DTH22 dth22(PinName sda, PinName scl, int addr);  // pin
+ *
+ * int main() {
+ *     err=dth22.readData();
+ *     if (err==0) {
+          printf("Temperature is %f.2 C\n",dht22.getTemperature());
+          printf("Humidity is %f.2 \%\n",dht22.getHumidity());
+       }
+ *
+ *
+ */
+
+#define DHT22_ERROR_VALUE -99.5
+
+typedef enum {
+    DHT_ERROR_NONE = 0,
+    DHT_BUS_HUNG,
+    DHT_ERROR_NOT_PRESENT,
+    DHT_ERROR_ACK_TOO_LONG,
+    DHT_ERROR_SYNC_TIMEOUT,
+    DHT_ERROR_DATA_TIMEOUT,
+    DHT_ERROR_CHECKSUM,
+    DHT_ERROR_TOO_QUICK
+} DHT22_ERROR;
+
+class DHT22 {
+private:
+    time_t  _lastReadTime;
+    PinName _data;
+    float   _lastHumidity;
+    float   _lastTemperature;
+public:
+    DHT22(PinName Data);
+    ~DHT22();
+    DHT22_ERROR readData(void);
+    float getHumidity();
+    float getTemperatureC();
+    void clockReset();
+};
+
+#endif /*_DHT22_H_*/