MAKING A TEMPERATURE AND HUMIDITY SENSOR INTERFACED TO A

16x2 DOTTED LCD DISPLAY

After my 1st year was over ,sitting in home i was bored so thought of creating a digital watch.I knew  how to do that but then thought of adding a temp and humidity sensor to it.So I ordered the DHT11 sensor from ventor shop it cost around rs 150 and easy to be interfaced with arduino. U can get it here :http://www.ventor.co.in/index.php?main_page=product_info&cPath=34_35&products_id=289&zenid=bd061a102228031d261191443ebd94b5 . I have written a small arduino program to interface it with arduino that to simply read the temp and humidity values and display it an serial monitor.

But now one day i noticed while standing on my bed that while the ac was working but still there was a significant temperature gradient moving from ground to roof.I mean the more up the more hotter i.e natural cold air is more heavier,but then what temp u set in ac u feel much cooler than that.And here was the idea for my brothers IRIS project which he has been telling me for long time.He is now in class 6 and I know getting ideas to be selected in national level is tough ,so i used to ignore that.But this idea seemed to be promising until i discovered the  inner working of (I FEEL technology in BLUE STAR,FOLLOW ME in panasonic etc) has already incorporated the idea into their models.the idea was simple its placing a sensor in the remote of the ac so that it knows what temperature we are actually feeling .

 Mean while to really justify this I needed a portable temperature sensor that can display the values.So thought of attaching a lcd display to the arduino.But its tougher than said. Interfacing a lcd from scratch can be very painful.I my self spent around a week learning things.Here's a good tutorial for beginners
http://www.lxdinc.com/application_notes/multiplexing_lcds . If u want to know the internal details and architecture of the lcd controller HITACHI HD44780 provides a very sound documentation of the internal working with every details of ROM,CGROM etc given.
    U can get the datasheet here https://www.sparkfun.com/datasheets/LCD/HD44780.pdf .
Now this provides the internal working. A  compatible lcd can be brought again from ventor .there are many variants i used JHD 162A.The datasheet is available in the product page.REMEMBER this product does not have the legs soldered to board u have to do it manually(very painful).ADVICE get a pair of bergstrips to attach be careful while soldering.too much heat can burn the chip.

Finally a picture showing temp and humidity:

in this post I discussed about my personal experience and a little technical details.Hope u enjoyed reading it.the links above provide extensive technical details.In the next post i will be discussing about the arduino code till then GOOD BYE.