{"id":1390,"date":"2013-01-06T12:41:14","date_gmt":"2013-01-06T10:41:14","guid":{"rendered":"http:\/\/sickel.net\/blogg\/?p=1390"},"modified":"2013-02-06T14:25:01","modified_gmt":"2013-02-06T12:25:01","slug":"arduino-thermometer-hygrometer","status":"publish","type":"post","link":"http:\/\/sickel.net\/blogg\/?p=1390","title":{"rendered":"Arduino thermometer \/ hygrometer"},"content":{"rendered":"

I am using an arduino uno bought in a kit<\/a> with a LCD\/button shield and a DHT11<\/a>, both parts bougth from dealextreme, although also available from a lot of other places.<\/p>\n

The DHT11 is connected to the arduino:
\n* pin 1 (signal) – digital 2
\n* pin 2 (Vcc) – 5v
\n* pin 3 (gnd) – gnd
\n

\"Connection\"

DHT22 break out board connected to arduino uno<\/p><\/div>
\n(The cables are taken from a discarded PC cabinet)<\/p>\n

Then the display is put on top and the sketch is downloaded:
\n

\"Complete

Complete arduiono \/ DHT22 termometer \/ hygrometer<\/p><\/div><\/p>\n

sketch:
\n
\n#include \"DHT.h\"
\n#include <liquidcrystal.h>
\nLiquidCrystal lcd(8, 9, 4, 5, 6, 7);<\/p>\n

#define DHTPIN 2 \/\/ what pin we're connected to<\/p>\n

\/\/ Uncomment whatever type you're using!
\n#define DHTTYPE DHT11 \/\/ DHT 11
\n\/\/#define DHTTYPE DHT22 \/\/ DHT 22 (AM2302)
\n\/\/#define DHTTYPE DHT21 \/\/ DHT 21 (AM2301)<\/p>\n

DHT dht(DHTPIN, DHTTYPE);<\/p>\n

void setup() {
\n lcd.begin(16,2);
\n dht.begin();
\n}<\/p>\n

void loop() {
\n \/\/ Reading temperature or humidity takes about 250 milliseconds!
\n \/\/ Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
\n float h = dht.readHumidity();
\n float t = dht.readTemperature();<\/p>\n

\/\/ check if returns are valid, if they are NaN (not a number) then something went wrong!
\n if (isnan(t) || isnan(h)) {
\n lcd.setCursor(5,1);
\n lcd.println(\"Failed to read from DHT\");
\n } else {
\n lcd.setCursor(5,1);
\n lcd.print(h);
\n lcd.print(\" %\");
\n lcd.setCursor(5,0);
\n lcd.print(t);
\n lcd.print(\" *C\");
\n }
\n}
\n<\/code><\/p>\n

The LiquidCrystal library should come with the arduino ide, the DHT library can be downloaded from http:\/\/playground.arduino.cc\/Main\/DHTLib<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

I am using an arduino uno bought in a kit with a LCD\/button shield and a DHT11, both parts bougth from dealextreme, although also available from a lot of other places. The DHT11 is connected to the arduino: * pin … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[33,1],"tags":[],"class_list":["post-1390","post","type-post","status-publish","format-standard","hentry","category-arduino","category-div"],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pnVtD-mq","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"http:\/\/sickel.net\/blogg\/index.php?rest_route=\/wp\/v2\/posts\/1390","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/sickel.net\/blogg\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/sickel.net\/blogg\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/sickel.net\/blogg\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/sickel.net\/blogg\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1390"}],"version-history":[{"count":6,"href":"http:\/\/sickel.net\/blogg\/index.php?rest_route=\/wp\/v2\/posts\/1390\/revisions"}],"predecessor-version":[{"id":1465,"href":"http:\/\/sickel.net\/blogg\/index.php?rest_route=\/wp\/v2\/posts\/1390\/revisions\/1465"}],"wp:attachment":[{"href":"http:\/\/sickel.net\/blogg\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1390"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/sickel.net\/blogg\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1390"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/sickel.net\/blogg\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1390"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}