"1. read the docs 2. while not working 2a. try really hard 2b. ask a specific question 2c. try really hard to understand and implement "

"Adafruit Tutorial on DHT-11 and DHT-22 (has example code and wiring diagram), and Arduino Library for communicating with DHT-22."

"please any one suggest some tutorial how to interface arduino with GSM MODEM SIM900... "

"thank u sir.i will check and tell the result. "

"It's good that you are using a proven circuit configuration.  This helps narrow down the possibilities.  It would be helpful if you stated the temperature readings you are getting over time.  Example, at power on, one second…"

"please explain briefly how to write this code "

"i use the detail given in the following attached file...the temperature value not stable..and also IC heated..what is the reason? any other interface circuit method available"

"Hi, I attached the datasheet because I am not sure if you have it.  Read it over if you haven't already. It is probably measuring the temperature correctly so you have to figure out what could be making the temperature go up.  It…"

"how to interface DHT-22 to arduino Leonardo?"

"DHT-22 available on ebay and other places is a one-wire Temperature and humidity sensor and communicates via a one-wire interface. Adafruit has libraries available for it."

"If you get lights and blocks then the LCD is working and not getting any data.  It looks like the JHD uses the HD44780 chipset, so it should work with the LiquidCrystal library.  I'd check your wiring, or redo it from scratch.…"

"Hi, I think this thread might help you.  I didn't read it, but it sounds like a similar problem. http://arduino.cc/forum/index.php/topic,26527.0.html"

"ya in my LCD BACKGROUND LIGHTS ON  and simply black colour blocks come.i use 16*2 JHD 162A  .this LCD is compatible with HD44780 ? "