History

Vowstar 09335d8252 Merge pull request #131 from javieryanez/patch-2 Error checking added in the example. Functions description added		2015-01-26 04:20:04 +08:00
..
README.md	Error checking added in the example. Functions description added	2015-01-25 20:20:48 +01:00
dht22.lua	Turn some variables to local	2015-01-25 20:13:07 +01:00

README.md

DHT22 module

This module is compatible with DHT22 and DHT21.
No need to use a resistor to connect the pin data of DHT22 to ESP8266.

Example

PIN = 4 --  data pin, GPIO2

dht22 = require("dht22")
dht22.read(PIN)
t = dht22.getTemperature()
h = dht22.getHumidity()

if h == -1 then
  print("Error reading from DHT22")
else
  -- temperature in degrees Celsius  and Farenheit
  print("Temperature: "..(t / 10).."."..(t % 10).." deg C")
  print("Temperature: "..(9 * t / 50 + 32).."."..(9 * t / 5 % 10).." deg F")

  -- humidity
  print("Humidity: "..(h/10).."."..(h%10).."%")
end

-- release module
dht22 = nil
package.loaded["dht22"]=nil

Functions

read

read(pin) Read humidity and temperature from DHT22.

Parameters:

pin - ESP8266 pin connect to data pin in DHT22

getHumidity

getHumidity()
Returns the humidity of the last reading.

Returns:

last humidity reading in per thousand

getTemperature

getTemperature()
Returns the temperature of the last reading.

Returns:

last temperature reading in 0.1ºC