trunk/Arduino/libraries/DHT_sensor_library/DHT.cpp

@@ -360,7 +360,9 @@ bool DHT::read(bool force) {
 // in the very latest IDE versions):
 //   https://github.com/arduino/Arduino/blob/master/hardware/arduino/avr/cores/arduino/wiring_pulse.c
 uint32_t DHT::expectPulse(bool level) {
-#if (F_CPU > 16000000L)
+// F_CPU is not be known at compile time on platforms such as STM32F103.
+// The preprocessor seems to evaluate it to zero in that case.
+#if (F_CPU > 16000000L) || (F_CPU == 0L)
   uint32_t count = 0;
 #else
   uint16_t count = 0; // To work fast enough on slower AVR boards

trunk/Arduino/libraries/DHT_sensor_library/DHT.h

@@ -41,13 +41,13 @@
 #endif
 
 /* Define types of sensors. */
-#define DHT11 11  /**< DHT TYPE 11 */
-#define DHT12 12  /**< DHY TYPE 12 */
-#define DHT22 22  /**< DHT TYPE 22 */
-#define DHT21 21  /**< DHT TYPE 21 */
-#define AM2301 21 /**< AM2301 */
+static const uint8_t DHT11{11};  /**< DHT TYPE 11 */
+static const uint8_t DHT12{12};  /**< DHY TYPE 12 */
+static const uint8_t DHT21{21};  /**< DHT TYPE 21 */
+static const uint8_t DHT22{22};  /**< DHT TYPE 22 */
+static const uint8_t AM2301{21}; /**< AM2301 */
 
-#if (TARGET_NAME == ARDUINO_NANO33BLE)
+#if defined(TARGET_NAME) && (TARGET_NAME == ARDUINO_NANO33BLE)
 #ifndef microsecondsToClockCycles
 /*!
  * As of 7 Sep 2020 the Arduino Nano 33 BLE boards do not have

trunk/Arduino/libraries/DHT_sensor_library/examples/DHTtester/DHTtester.ino

@@ -20,7 +20,8 @@
 // NOTE: If using a board with 3.3V logic like an Arduino Due connect pin 1
 // to 3.3V instead of 5V!
 // Connect pin 2 of the sensor to whatever your DHTPIN is
-// Connect pin 4 (on the right) of the sensor to GROUND
+// Connect pin 3 (on the right) of the sensor to GROUND (if your sensor has 3 pins)
+// Connect pin 4 (on the right) of the sensor to GROUND and leave the pin 3 EMPTY (if your sensor has 4 pins)
 // Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor
 
 // Initialize DHT sensor.

trunk/Arduino/libraries/DHT_sensor_library/library.properties

@@ -1,5 +1,5 @@
 name=DHT sensor library
-version=1.4.0
+version=1.4.6
 author=Adafruit
 maintainer=Adafruit <info@adafruit.com>
 sentence=Arduino library for DHT11, DHT22, etc Temp & Humidity Sensors