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# DHT12

Arduino library for I2C DHT12 temperature and humidity sensor.


## Description

The library should be initiated by calling the **begin()** function, 
optionally **begin(dataPin, clockPin)** for **ESP32** and similar platforms.

Thereafter one has to call the **read()** function to do the actual reading,
and with **getTemperature()** and **getHumidity()** to get the read values.
Calling these latter again will return the same values until a new **read()** is called.


## Interface


### Constructor

- **DHT12(TwoWire \*wire)** constructor, using a specific Wire (I2C bus).
- **bool begin(uint8_t dataPin, uint8_t clockPin)** begin for ESP32 et al, to set I2C bus pins
- **bool begin()** initializer for non ESP32. Returns true if connected.
- **bool isConnected()** returns true if the address of the DHT12 can be seen on the I2C bus. (since 0.3.2)


### Core

- **int8_t read()** read the sensor and store the values internally. It returns the status of the read which should be 0.
- **float getHumidity()** returns last Humidity read, or -999 in case of error.
- **float getTemperature()** returns last Temperature read, or -999 in case of error.
- **uint32_t lastRead()** returns the timestamp in milliseconds since startup of the last successful read. (added in 0.3.1)


### Offset

- **void setHumOffset(float offset)** set an offset to calibrate (1st order) the sensor.
- **float getHumOffset()** return current offset, default 0.
- **void setTempOffset(float offset)** set an offset to calibrate (1st order) the sensor
- **float getTempOffset()** return current offset, default 0.


### 0.3.0

- The members **temperature** and **humidity** became private in 0.3.0.
- added offset for temperature and humidity.


## Operation

See examples


## Future

- check for optimizations. although I2C overhead is much more...
- test at different I2C speeds 400 KHz should be possible.
- add examples.
- **void setIgnoreChecksum(bool = false)** ignore checksum flag speeds up communication a bit
- **bool getIgnoreChecksum()** get status. for completeness.
-