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5b67113 Jan 3, 2014
@nethoncho @jkuchta @ringerc
83 lines (71 sloc) 1.8 KB
#ifndef _DHT22_H_
#define _DHT22_H_
#include <inttypes.h>
#define DHT22_ERROR_VALUE -995
typedef enum
{
DHT_ERROR_NONE = 0,
DHT_BUS_HUNG,
DHT_ERROR_NOT_PRESENT,
DHT_ERROR_ACK_TOO_LONG,
DHT_ERROR_SYNC_TIMEOUT,
DHT_ERROR_DATA_TIMEOUT,
DHT_ERROR_CHECKSUM,
DHT_ERROR_TOOQUICK
} DHT22_ERROR_t;
class DHT22
{
private:
uint8_t _bitmask;
volatile uint8_t *_baseReg;
unsigned long _lastReadTime;
short int _lastHumidity;
short int _lastTemperature;
public:
DHT22(uint8_t pin);
DHT22_ERROR_t readData();
short int getHumidityInt();
short int getTemperatureCInt();
void clockReset();
#if !defined(DHT22_NO_FLOAT)
float getHumidity();
float getTemperatureC();
float getTemperatureF();
#endif
};
// Report the humidity in .1 percent increments, such that 635 means 63.5% relative humidity
//
// Converts from the internal integer format on demand, so you might want
// to cache the result.
inline short int DHT22::getHumidityInt()
{
return _lastHumidity;
}
// Get the temperature in decidegrees C, such that 326 means 32.6 degrees C.
// The temperature may be negative, so be careful when handling the fractional part.
inline short int DHT22::getTemperatureCInt()
{
return _lastTemperature;
}
#if !defined(DHT22_NO_FLOAT)
// Return the percentage relative humidity in decimal form
inline float DHT22::getHumidity()
{
return float(_lastHumidity)/10;
}
#endif
#if !defined(DHT22_NO_FLOAT)
// Return the percentage relative humidity in decimal form
//
// Converts from the internal integer format on demand, so you might want
// to cache the result.
inline float DHT22::getTemperatureC()
{
return float(_lastTemperature)/10;
}
inline float DHT22::getTemperatureF()
{
return float(_lastTemperature) / 10 * 9 / 5 + 32;
}
#endif //DHT22_SUPPORT_FLOAT
#endif /*_DHT22_H_*/