mirror of
https://github.com/RobTillaart/Arduino.git
synced 2024-10-03 18:09:02 -04:00
72 lines
2.8 KiB
Markdown
72 lines
2.8 KiB
Markdown
|
|
[](https://github.com/marketplace/actions/arduino_ci)
|
|
[](https://github.com/RobTillaart/DHT12/actions/workflows/arduino-lint.yml)
|
|
[](https://github.com/RobTillaart/DHT12/actions/workflows/jsoncheck.yml)
|
|
[](https://github.com/RobTillaart/DHT12/blob/master/LICENSE)
|
|
[](https://github.com/RobTillaart/DHT12/releases)
|
|
|
|
|
|
# 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.
|
|
-
|
|
|
|
|