Updated DHT_example

Updated DHT_example to remove while loop
Increased version numbers

firmware/PietteTech_DHT.cpp

@@ -1,6 +1,6 @@
 /*
  * FILE:        PietteTech_DHT.cpp
- * VERSION:     0.2
+ * VERSION:     0.3
  * PURPOSE:     Spark Interrupt driven lib for DHT sensors
  * LICENSE:     GPL v3 (http://www.gnu.org/licenses/gpl.html)
  *

firmware/PietteTech_DHT.h

@@ -1,6 +1,6 @@
 /*
  * FILE:        PietteTech_DHT.h
- * VERSION:     0.2
+ * VERSION:     0.3
  * PURPOSE:     Spark Interrupt driven lib for DHT sensors
  * LICENSE:     GPL v3 (http://www.gnu.org/licenses/gpl.html)
  *

firmware/examples/DHT_2sensor.ino

@@ -1,6 +1,6 @@
 /*
  * FILE:        DHT_2sensor.ino
- * VERSION:     0.2
+ * VERSION:     0.3
  * PURPOSE:     Example that uses DHT library with two sensors
  * LICENSE:     GPL v3 (http://www.gnu.org/licenses/gpl.html)
  *

firmware/examples/DHT_example.ino

@@ -1,11 +1,14 @@
 /*
  * FILE:        DHT_example.ino
- * VERSION:     0.2
+ * VERSION:     0.3
  * PURPOSE:     Example that uses DHT library with two sensors
  * LICENSE:     GPL v3 (http://www.gnu.org/licenses/gpl.html)
  *
- * Calls acquire on one sensor and monitors the results for long term
- * analysis.  It uses DHT.acquire and DHT.acquiring
+ * Example that start acquisition of DHT sensor and allows the
+ * loop to continue until the acquisition has completed
+ * It uses DHT.acquire and DHT.acquiring
+ *
+ * Change DHT_SAMPLE_TIME to vary the frequency of samples
  *
  * Scott Piette (Piette Technologies) [email protected]
  *      January 2014        Original Spark Port
@@ -15,15 +18,21 @@
 
 #include "PietteTech_DHT/PietteTech_DHT.h"
 
-#define DHTTYPE  DHT22       // Sensor type DHT11/21/22/AM2301/AM2302
-#define DHTPIN   3           // Digital pin for communications
+// system defines
+#define DHTTYPE  DHT22              // Sensor type DHT11/21/22/AM2301/AM2302
+#define DHTPIN   3         	    // Digital pin for communications
+#define DHT_SAMPLE_INTERVAL   2000  // Sample every two seconds
 
 //declaration
 void dht_wrapper(); // must be declared before the lib initialization
 
 // Lib instantiate
 PietteTech_DHT DHT(DHTPIN, DHTTYPE, dht_wrapper);
-int n;      // counter
+
+// globals
+unsigned int DHTnextSampleTime;	    // Next time we want to start sample
+bool bDHTstarted;		    // flag to indicate we started acquisition
+int n;                              // counter
 
 void setup()
 {
@@ -36,8 +45,11 @@ void setup()
     Serial.print("LIB version: ");
     Serial.println(DHTLIB_VERSION);
     Serial.println("---------------");
+
+    DHTnextSampleTime = 0;  // Start the first sample immediately
 }
 
+
 // This wrapper is in charge of calling
 // mus be defined like this for the lib work
 void dht_wrapper() {
@@ -46,64 +58,73 @@ void dht_wrapper() {
 
 void loop()
 {
-    Serial.print("\n");
-    Serial.print(n);
-    Serial.print(": Retrieving information from sensor: ");
-    Serial.print("Read sensor: ");
-   //delay(100);
-
-    DHT.acquire();
-    while (DHT.acquiring()) ;
-
-    int result = DHT.getStatus();
-
-    switch (result) {
-        case DHTLIB_OK:
-            Serial.println("OK");
-            break;
-        case DHTLIB_ERROR_CHECKSUM:
-            Serial.println("Error\n\r\tChecksum error");
-            break;
-        case DHTLIB_ERROR_ISR_TIMEOUT:
-            Serial.println("Error\n\r\tISR time out error");
-            break;
-        case DHTLIB_ERROR_RESPONSE_TIMEOUT:
-            Serial.println("Error\n\r\tResponse time out error");
-            break;
-        case DHTLIB_ERROR_DATA_TIMEOUT:
-            Serial.println("Error\n\r\tData time out error");
-            break;
-        case DHTLIB_ERROR_ACQUIRING:
-            Serial.println("Error\n\r\tAcquiring");
-            break;
-        case DHTLIB_ERROR_DELTA:
-            Serial.println("Error\n\r\tDelta time to small");
-            break;
-        case DHTLIB_ERROR_NOTSTARTED:
-            Serial.println("Error\n\r\tNot started");
-            break;
-        default:
-            Serial.println("Unknown error");
-            break;
+  // Check if we need to start the next sample
+  if (millis() > DHTnextSampleTime) {
+	if (!bDHTstarted) {		// start the sample
+	    Serial.print("\n");
+	    Serial.print(n);
+	    Serial.print(": Retrieving information from sensor: ");
+	    DHT.acquire();
+	    bDHTstarted = true;
+	}
+
+	if (!DHT.acquiring()) {		// has sample completed?
+
+	    // get DHT status
+	    int result = DHT.getStatus();
+
+	    Serial.print("Read sensor: ");
+	    switch (result) {
+		case DHTLIB_OK:
+		    Serial.println("OK");
+		    break;
+		case DHTLIB_ERROR_CHECKSUM:
+		    Serial.println("Error\n\r\tChecksum error");
+		    break;
+		case DHTLIB_ERROR_ISR_TIMEOUT:
+		    Serial.println("Error\n\r\tISR time out error");
+		    break;
+		case DHTLIB_ERROR_RESPONSE_TIMEOUT:
+		    Serial.println("Error\n\r\tResponse time out error");
+		    break;
+		case DHTLIB_ERROR_DATA_TIMEOUT:
+		    Serial.println("Error\n\r\tData time out error");
+		    break;
+		case DHTLIB_ERROR_ACQUIRING:
+		    Serial.println("Error\n\r\tAcquiring");
+		    break;
+		case DHTLIB_ERROR_DELTA:
+		    Serial.println("Error\n\r\tDelta time to small");
+		    break;
+		case DHTLIB_ERROR_NOTSTARTED:
+		    Serial.println("Error\n\r\tNot started");
+		    break;
+		default:
+		    Serial.println("Unknown error");
+		    break;
+	    }
+
+	    Serial.print("Humidity (%): ");
+	    Serial.println(DHT.getHumidity(), 2);
+
+	    Serial.print("Temperature (oC): ");
+	    Serial.println(DHT.getCelsius(), 2);
+
+	    Serial.print("Temperature (oF): ");
+	    Serial.println(DHT.getFahrenheit(), 2);
+
+	    Serial.print("Temperature (K): ");
+	    Serial.println(DHT.getKelvin(), 2);
+
+	    Serial.print("Dew Point (oC): ");
+	    Serial.println(DHT.getDewPoint());
+
+	    Serial.print("Dew Point Slow (oC): ");
+	    Serial.println(DHT.getDewPointSlow());
+
+	    n++;  // increment counter
+	    bDHTstarted = false;  // reset the sample flag so we can take another
+	    DHTnextSampleTime = millis() + DHT_SAMPLE_INTERVAL;  // set the time for next sample
+	}
     }
-    Serial.print("Humidity (%): ");
-    Serial.println(DHT.getHumidity(), 2);
-
-    Serial.print("Temperature (oC): ");
-    Serial.println(DHT.getCelsius(), 2);
-
-    Serial.print("Temperature (oF): ");
-    Serial.println(DHT.getFahrenheit(), 2);
-
-    Serial.print("Temperature (K): ");
-    Serial.println(DHT.getKelvin(), 2);
-
-    Serial.print("Dew Point (oC): ");
-    Serial.println(DHT.getDewPoint());
-
-    Serial.print("Dew Point Slow (oC): ");
-    Serial.println(DHT.getDewPointSlow());
-
-    n++;
-    delay(2500);
 }

firmware/examples/DHT_simple.ino

@@ -1,6 +1,6 @@
 /*
  * FILE:        DHT_simple.ino
- * VERSION:     0.2
+ * VERSION:     0.3
  * PURPOSE:     Example that uses DHT library with two sensors
  * LICENSE:     GPL v3 (http://www.gnu.org/licenses/gpl.html)
  *

spark.json

@@ -1,6 +1,6 @@
 {
     "name": "PietteTech_DHT",
-    "version": "0.0.2",
+    "version": "0.0.3",
     "author": "Scott Piette [email protected]",
     "license": "GPL v3 (http://www.gnu.org/licenses/gpl.html)",
     "description": "Interrupt driven DHT11/21/22 Sensor library"