DHT Module¶
Since | Origin / Contributor | Maintainer | Source |
---|---|---|---|
2015-06-17 | RobTillaart | Vowstar | dhtlib |
Constants¶
Constants for various functions.
dht.OK
, dht.ERROR_CHECKSUM
, dht.ERROR_TIMEOUT
represent the potential values for the DHT read status
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 Constantstemp
temperature (see note below)humi
humidity (see note below)temp_dec
temperature decimalhumi_dec
humidity decimal
Note
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
.
Example¶
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),
temp_dec,
math.floor(humi),
humi_dec
))
-- 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 Constantstemp
temperature (see note below)humi
humidity (see note below)temp_dec
temperature decimalhumi_dec
humidity decimal
Note
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
.
See also¶
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 Constantstemp
temperature (see note below)humi
humidity (see note below)temp_dec
temperature decimalhumi_dec
humidity decimal
Note
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
.