Cause interrupts to be reenabled if a timeout occurs while waiting for the sensor.

DHT.cpp

@@ -140,7 +140,8 @@ boolean DHT::read(void) {
 
   // Turn off interrupts temporarily because the next sections are timing critical
   // and we don't want any interruptions.
-  noInterrupts();
+  {
+    InterruptLock lock;
 
     // End the start signal by setting data line high for 40 microseconds.
     digitalWrite(_pin, HIGH);
@@ -193,9 +194,9 @@ boolean DHT::read(void) {
       // cycle count so this must be a zero.  Nothing needs to be changed in the
       // stored data.
     }
+    // Timing critical code is now complete.
 
-  // Re-enable interrupts, timing critical code is complete.
-  interrupts();
+  }
 
   DEBUG_PRINTLN(F("Received:"));
   DEBUG_PRINT(data[0], HEX); DEBUG_PRINT(F(", "));

DHT.h

@@ -57,4 +57,15 @@ class DHT {
 
 };
 
+class InterruptLock {
+  public:
+   InterruptLock() {
+    noInterrupts();
+   }
+   ~InterruptLock() {
+    interrupts();
+   }
+
+};
+
 #endif