90 lines
1.7 KiB
Markdown
90 lines
1.7 KiB
Markdown
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# DHTxx module
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This module is compatible with DHT11, DHT21 and DHT22.
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And is able to auto-select wheather you are using DHT11 or DHT2x
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No need to use a resistor to connect the pin data of DHT22 to ESP8266.
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##Integer Verison[When using DHT11, Float version is useless...]
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### Example
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```lua
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PIN = 4 -- data pin, GPIO2
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DHT= require("dht_lib")
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DHT.read(PIN)
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t = DHT.getTemperature()
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h = DHT.getHumidity()
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if h == nil then
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print("Error reading from DHTxx")
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else
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-- temperature in degrees Celsius and Farenheit
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print("Temperature: "..((t-(t % 10)) / 10).."."..(t % 10).." deg C")
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print("Temperature: "..(9 * t / 50 + 32).."."..(9 * t / 5 % 10).." deg F")
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-- humidity
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print("Humidity: "..((h - (h % 10)) / 10).."."..(h % 10).."%")
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end
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-- release module
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DHT = nil
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package.loaded["dht_lib"]=nil
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```
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##Float Verison
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###Example
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```lua
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PIN = 4 -- data pin, GPIO2
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DHT= require("dht_lib")
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DHT.read(PIN)
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t = DHT.getTemperature()
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h = DHT.getHumidity()
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if h == nil then
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print("Error reading from DHT11/22")
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else
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-- temperature in degrees Celsius and Farenheit
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-- floating point and integer version:
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print("Temperature: "..(t/10).." deg C")
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print("Temperature: "..(9 * t / 50 + 32).." deg F")
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-- humidity
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print("Humidity: "..(h/10).."%")
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end
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-- release module
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DHT = nil
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package.loaded["dht_lib"]=nil
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```
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## Functions
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###read
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read(pin)
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Read humidity and temperature from DHTxx(11,21,22...).
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**Parameters:**
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* pin - ESP8266 pin connect to data pin
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### getHumidity
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getHumidity()
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Returns the humidity of the last reading.
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**Returns:**
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* last humidity reading in per thousand
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### getTemperature
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getTemperature()
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Returns the temperature of the last reading.
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**Returns:**
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* last temperature reading in(dht22) 0.1ºC (dht11)1ºC
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*
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