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# DHT Module
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| Since | Origin / Contributor | Maintainer | Source |
| :----- | :-------------------- | :---------- | :------ |
| 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.
`dht.OK` , `dht.ERROR_CHECKSUM` , `dht.ERROR_TIMEOUT` represent the potential values for the DHT read status
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## dht.read()
Read all kinds of DHT sensors, including DHT11, 21, 22, 33, 44 humidity temperature combo sensor.
#### Syntax
`dht.read(pin)`
#### Parameters
`pin` pin number of DHT sensor (can't be 0), type is number
#### Returns
- `status` as defined in Constants
- `temp` temperature (see note below)
- `humi` humidity (see note below)
- `temp_dec` temperature decimal
- `humi_dec` humidity decimal
!!! 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
```lua
pin = 5
status, temp, humi, temp_dec, humi_dec = dht.read(pin)
if status == dht.OK then
-- Integer firmware using this example
print(string.format("DHT Temperature:%d.%03d;Humidity:%d.%03d\r\n",
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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))
-- Float firmware using this example
print("DHT Temperature:"..temp..";".."Humidity:"..humi)
elseif status == dht.ERROR_CHECKSUM then
print( "DHT Checksum error." )
elseif status == dht.ERROR_TIMEOUT then
print( "DHT timed out." )
end
```
## dht.read11()
Read DHT11 humidity temperature combo sensor.
#### Syntax
`dht.read11(pin)`
#### Parameters
`pin` pin number of DHT11 sensor (can't be 0), type is number
#### Returns
- `status` as defined in Constants
- `temp` temperature (see note below)
- `humi` humidity (see note below)
- `temp_dec` temperature decimal
- `humi_dec` humidity decimal
!!! 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
[dht.read() ](#dhtread )
## dht.readxx()
Read all kinds of DHT sensors, except DHT11.
####Syntax
`dht.readxx(pin)`
#### Parameters
`pin` pin number of DHT sensor (can't be 0), type is number
#### Returns
- `status` as defined in Constants
- `temp` temperature (see note below)
- `humi` humidity (see note below)
- `temp_dec` temperature decimal
- `humi_dec` humidity decimal
!!! note "Note:"
2016-01-13 23:30:39 +01:00
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
[dht.read() ](#dhtread )