A minimal library for the DHT11.

Dependencies:   mbed

Dependents:   EXP10_DHT11_LCD Sushil_MODSERIAL Core1000_SmartFarm idd_summer17_hw3_evey_jenny_seiyoung ... more

Files at this revision

API Documentation at this revision

Comitter:
fossum_13
Date:
Mon Feb 16 01:43:08 2015 +0000
Parent:
0:c1da310d3e8a
Commit message:
Added documentation and some minor improvements. Not backwards compatible!

Changed in this revision

Dht11.cpp Show annotated file Show diff for this revision Revisions of this file
Dht11.h Show annotated file Show diff for this revision Revisions of this file
diff -r c1da310d3e8a -r 5da6f6de3e42 Dht11.cpp
--- a/Dht11.cpp	Sun Feb 15 02:09:00 2015 +0000
+++ b/Dht11.cpp	Mon Feb 16 01:43:08 2015 +0000
@@ -1,16 +1,15 @@
 #include "Dht11.h"
 
-Dht11::Dht11(PinName p) : _pin(p) {
+Dht11::Dht11(PinName const &p) : _pin(p) {
     // Set creation time so we can make 
     // sure we pause at least 1 second for 
     // startup.
     _timer.start();
+    
+    _temperature = 0;
+    _humidity = 0;
 }
 
-// Return values:
-// DHTLIB_OK
-// DHTLIB_ERROR_CHECKSUM
-// DHTLIB_ERROR_TIMEOUT
 int Dht11::read()
 {
     // BUFFER TO RECEIVE
@@ -77,10 +76,14 @@
     return DHTLIB_OK;
 }
 
-int Dht11::temperature() {
+float Dht11::getFahrenheit() {
+    return((_temperature * 1.8) + 32);
+}
+
+int Dht11::getCelsius() {
     return(_temperature);
 }
 
-int Dht11::humidity() {
+int Dht11::getHumidity() {
     return(_humidity);
 }
diff -r c1da310d3e8a -r 5da6f6de3e42 Dht11.h
--- a/Dht11.h	Sun Feb 15 02:09:00 2015 +0000
+++ b/Dht11.h	Mon Feb 16 01:43:08 2015 +0000
@@ -7,17 +7,67 @@
 #define DHTLIB_ERROR_CHECKSUM   -1
 #define DHTLIB_ERROR_TIMEOUT    -2
 
-class Dht11 {
+/** Class for the DHT11 sensor.
+ * 
+ * Example:
+ * @code
+ * #include "mbed.h"
+ * #include "Dht11.h"
+ *
+ * Serial pc(USBTX, USBRX);
+ * Dht11 sensor(PTD7);
+ * 
+ * int main() {
+ *     sensor.read()
+ *     pc.printf("T: %f, H: %d\r\n", sensor.getFahrenheit(), sensor.getHumidity());
+ * }
+ * @endcode
+ */
+class Dht11
+{
 public:
-    Dht11(PinName p);
+    /** Construct the sensor object.
+     *
+     * @param pin PinName for the sensor pin.
+     */
+    Dht11(PinName const &p);
+    
+    /** Update the humidity and temp from the sensor.
+     *
+     * @returns
+     *   0 on success, otherwise error.
+     */
     int read();
-    int temperature();
-    int humidity();
+    
+    /** Get the temp(f) from the saved object.
+     *
+     * @returns
+     *   Fahrenheit float
+     */
+    float getFahrenheit();
     
+    /** Get the temp(c) from the saved object.
+     *
+     * @returns
+     *   Celsius int
+     */
+    int getCelsius();
+    
+    /** Get the humidity from the saved object.
+     *
+     * @returns
+     *   Humidity percent int
+     */
+    int getHumidity();
+
 private:
+    /// percentage of humidity
     int _humidity;
+    /// celsius
     int _temperature;
+    /// pin to read the sensor info on
     DigitalInOut _pin;
+    /// times startup (must settle for at least a second)
     Timer _timer;
 };