2021-01-29 06:31:58 -05:00
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[](https://github.com/marketplace/actions/arduino_ci)
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2021-10-25 11:35:53 -04:00
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[](https://github.com/RobTillaart/DHT12/actions/workflows/arduino-lint.yml)
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[](https://github.com/RobTillaart/DHT12/actions/workflows/jsoncheck.yml)
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2021-01-29 06:31:58 -05:00
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[](https://github.com/RobTillaart/DHT12/blob/master/LICENSE)
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[](https://github.com/RobTillaart/DHT12/releases)
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2020-11-27 05:10:47 -05:00
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# DHT12
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Arduino library for I2C DHT12 temperature and humidity sensor.
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2021-10-25 11:35:53 -04:00
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2020-11-27 05:10:47 -05:00
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## Description
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The library should be initiated by calling the **begin()** function,
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optionally **begin(dataPin, clockPin)** for **ESP32** and similar platforms.
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Thereafter one has to call the **read()** function to do the actual reading,
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and with **getTemperature()** and **getHumidity()** to get the read values.
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Calling these latter again will return the same values until a new **read()** is called.
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## Interface
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### Constructor
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- **DHT12(TwoWire \*wire)** constructor, using a specific Wire (I2C bus).
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- **bool begin(uint8_t dataPin, uint8_t clockPin)** begin for ESP32 et al, to set I2C bus pins
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- **bool begin()** initializer for non ESP32. Returns true if connected.
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- **bool isConnected()** returns true if the address of the DHT12 can be seen on the I2C bus. (since 0.3.2)
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### Core
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- **int8_t read()** read the sensor and store the values internally. It returns the status of the read which should be 0.
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- **float getHumidity()** returns last Humidity read, or -999 in case of error.
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- **float getTemperature()** returns last Temperature read, or -999 in case of error.
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- **uint32_t lastRead()** returns the timestamp in milliseconds since startup of the last successful read. (added in 0.3.1)
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### Offset
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- **void setHumOffset(float offset)** set an offset to calibrate (1st order) the sensor.
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- **float getHumOffset()** return current offset, default 0.
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- **void setTempOffset(float offset)** set an offset to calibrate (1st order) the sensor
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- **float getTempOffset()** return current offset, default 0.
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### 0.3.0
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- The members **temperature** and **humidity** became private in 0.3.0.
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- added offset for temperature and humidity.
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2020-11-27 05:10:47 -05:00
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## Operation
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See examples
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## Future
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- check for optimizations. although I2C overhead is much more...
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- test at different I2C speeds 400 KHz should be possible.
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- add examples.
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- **void setIgnoreChecksum(bool = false)** ignore checksum flag speeds up communication a bit
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- **bool getIgnoreChecksum()** get status. for completeness.
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-
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