99 lines
2.8 KiB
Markdown
99 lines
2.8 KiB
Markdown
# DHT Module
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| Since | Origin / Contributor | Maintainer | Source |
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| :----- | :-------------------- | :---------- | :------ |
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| 2015-06-17 | [RobTillaart](https://github.com/RobTillaart/Arduino/tree/master/libraries/DHTlib) | [Vowstar](https://github.com/vowstar) | [dhtlib](../../../app/dhtlib/)|
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## Constants
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Constants for various functions.
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`dht.OK`, `dht.ERROR_CHECKSUM`, `dht.ERROR_TIMEOUT` represent the potential values for the DHT read status
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## dht.read()
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Read all kinds of DHT sensors, including DHT11, 21, 22, 33, 44 humidity temperature combo sensor.
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#### Syntax
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`dht.read(pin)`
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#### Parameters
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`pin` pin number of DHT sensor (can't be 0), type is number
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#### Returns
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- `status` as defined in Constants
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- `temp` temperature (see note below)
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- `humi` humidity (see note below)
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- `temp_dec` temperature decimal
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- `humi_dec` humidity decimal
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!!! note "Note:"
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If using float firmware then `temp` and `humi` are floating point numbers. On an integer firmware, the final values have to be concatenated from `temp` and `temp_dec` / `humi` and `hum_dec`.
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#### Example
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```lua
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pin = 5
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status, temp, humi, temp_dec, humi_dec = dht.read(pin)
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if status == dht.OK then
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-- Integer firmware using this example
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print(string.format("DHT Temperature:%d.%03d;Humidity:%d.%03d\r\n",
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math.floor(temp),
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temp_dec,
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math.floor(humi),
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humi_dec
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))
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-- Float firmware using this example
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print("DHT Temperature:"..temp..";".."Humidity:"..humi)
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elseif status == dht.ERROR_CHECKSUM then
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print( "DHT Checksum error." )
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elseif status == dht.ERROR_TIMEOUT then
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print( "DHT timed out." )
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end
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```
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## dht.read11()
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Read DHT11 humidity temperature combo sensor.
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#### Syntax
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`dht.read11(pin)`
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#### Parameters
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`pin` pin number of DHT11 sensor (can't be 0), type is number
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#### Returns
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- `status` as defined in Constants
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- `temp` temperature (see note below)
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- `humi` humidity (see note below)
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- `temp_dec` temperature decimal
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- `humi_dec` humidity decimal
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!!! note "Note:"
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If using float firmware then `temp` and `humi` are floating point numbers. On an integer firmware, the final values have to be concatenated from `temp` and `temp_dec` / `humi` and `hum_dec`.
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#### See also
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[dht.read()](#dhtread)
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## dht.readxx()
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Read all kinds of DHT sensors, except DHT11.
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####Syntax
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`dht.readxx(pin)`
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#### Parameters
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`pin` pin number of DHT sensor (can't be 0), type is number
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#### Returns
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- `status` as defined in Constants
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- `temp` temperature (see note below)
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- `humi` humidity (see note below)
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- `temp_dec` temperature decimal
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- `humi_dec` humidity decimal
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!!! note "Note:"
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If using float firmware then `temp` and `humi` are floating point numbers. On an integer firmware, the final values have to be concatenated from `temp` and `temp_dec` / `humi` and `hum_dec`.
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#### See also
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[dht.read()](#dhtread)
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