DHT-sensor-library/DHT.h

107 lines
3.0 KiB
C++

/*!
* @file DHT.h
*
* This is a library for DHT series of low cost temperature/humidity sensors.
*
* You must have Adafruit Unified Sensor Library library installed to use this
* class.
*
* Adafruit invests time and resources providing this open source code,
* please support Adafruit andopen-source hardware by purchasing products
* from Adafruit!
*
* Written by Adafruit Industries.
*
* MIT license, all text above must be included in any redistribution
*/
#ifndef DHT_H
#define DHT_H
#include "Arduino.h"
/* Uncomment to enable printing out nice debug messages. */
//#define DHT_DEBUG
#define DEBUG_PRINTER \
Serial /**< Define where debug output will be printed. \
*/
/* Setup debug printing macros. */
#ifdef DHT_DEBUG
#define DEBUG_PRINT(...) \
{ DEBUG_PRINTER.print(__VA_ARGS__); }
#define DEBUG_PRINTLN(...) \
{ DEBUG_PRINTER.println(__VA_ARGS__); }
#else
#define DEBUG_PRINT(...) \
{} /**< Debug Print Placeholder if Debug is disabled */
#define DEBUG_PRINTLN(...) \
{} /**< Debug Print Line Placeholder if Debug is disabled */
#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 */
#if (TARGET_NAME==ARDUINO_NANO33BLE)
// As of 7 Sep 2020 the Arduino Nano 33 BLE boards do not have microsecondsToClockCycles defined.
#ifndef microsecondsToClockCycles
#define microsecondsToClockCycles(a) ( (a) * (SystemCoreClock / 1000000L) )
#endif
#endif
/*!
* @brief Class that stores state and functions for DHT
*/
class DHT {
public:
DHT(uint8_t pin, uint8_t type, uint8_t count = 6);
void begin(uint8_t usec = 55);
float readTemperature(bool S = false, bool force = false);
float convertCtoF(float);
float convertFtoC(float);
float computeHeatIndex(bool isFahrenheit = true);
float computeHeatIndex(float temperature, float percentHumidity,
bool isFahrenheit = true);
float readHumidity(bool force = false);
bool read(bool force = false);
private:
uint8_t data[5];
uint8_t _pin, _type;
#ifdef __AVR
// Use direct GPIO access on an 8-bit AVR so keep track of the port and
// bitmask for the digital pin connected to the DHT. Other platforms will use
// digitalRead.
uint8_t _bit, _port;
#endif
uint32_t _lastreadtime, _maxcycles;
bool _lastresult;
uint8_t pullTime; // Time (in usec) to pull up data line before reading
uint32_t expectPulse(bool level);
};
/*!
* @brief Class that defines Interrupt Lock Avaiability
*/
class InterruptLock {
public:
InterruptLock() {
#if !defined(ARDUINO_ARCH_NRF52)
noInterrupts();
#endif
}
~InterruptLock() {
#if !defined(ARDUINO_ARCH_NRF52)
interrupts();
#endif
}
};
#endif