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Merge pull request #329 from MarsTechHAN/patch-2 

Add support to DHT11 and add some comments.
This commit is contained in:
Vowstar 2015-04-04 08:12:29 +08:00
parent b0e34e11bf 1bc81f4c3e
commit 263179ea14
1 changed files with 55 additions and 22 deletions
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77
lua_modules/dht22/README.md
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@ -1,46 +1,78 @@
# DHT22 module
# DHTxx module
This module is compatible with DHT22 and DHT21.
Supports nodemcu with or without floating point.
This module is compatible with DHT11, DHT21 and DHT22.
No need to use a resistor to connect the pin data of DHT22 to ESP8266.
## Example
##Integer Verison[When using DHT11, Float version is useless...]
### Example
```lua
PIN = 4 -- data pin, GPIO2
dht22 = require("dht22")
dht22.read(PIN)
t = dht22.getTemperature()
h = dht22.getHumidity()
DHT= require("dht_lib")
--dht.read11(PIN)
DHT.read22(PIN)
t = DHT.getTemperature()
h = DHT.getHumidity()
if h == nil then
print("Error reading from DHT22")
print("Error reading from DHT11/22")
else
-- temperature in degrees Celsius and Farenheit
-- floating point and integer version:
print("Temperature: "..((t-(t % 10)) / 10).."."..(t % 10).." deg C")
-- only integer version:
print("Temperature: "..(9 * t / 50 + 32).."."..(9 * t / 5 % 10).." deg F")
-- only float point version:
print("Temperature: "..(9 * t / 50 + 32).." deg F")
-- humidity
-- floating point and integer version
print("Humidity: "..((h - (h % 10)) / 10).."."..(h % 10).."%")
end
-- release module
dht22 = nil
package.loaded["dht22"]=nil
DHT = nil
package.loaded["dht_lib"]=nil
```
##Float Verison
###Example
```lua
PIN = 4 -- data pin, GPIO2
DHT= require("dht_lib")
--dht.read11(PIN)
DHT.read22(PIN)
t = DHT.getTemperature()
h = DHT.getHumidity()
if h == nil then
print("Error reading from DHT11/22")
else
-- temperature in degrees Celsius and Farenheit
-- floating point and integer version:
print("Temperature: "..t.." deg C")
print("Temperature: "..(9 * t / 50 + 32).." deg F")
-- humidity
print("Humidity: "..h.."%")
end
-- release module
DHT = nil
package.loaded["dht_lib"]=nil
```
## Functions
### read
read(pin)
Read humidity and temperature from DHT22.
### read11
read11(pin)
Read humidity and temperature from DHT11.
###read22
read22(pin)
Read humidity and temperature from DHT22/21.
**Parameters:**
* pin - ESP8266 pin connect to data pin in DHT22
* pin - ESP8266 pin connect to data pin
### getHumidity
getHumidity()
@ -54,5 +86,6 @@ getTemperature()
Returns the temperature of the last reading.
**Returns:**
* last temperature reading in 0.1ºC
* last temperature reading in(dht22) 0.1ºC (dht11)1ºC
*