Newbie: Dunno How to get started

[ckyz]

i just learn PIC 16F84 microcontroller and not familiar with it....and i m goin to do a project bout water level controller and display.

description: i need a water level sensor to sense the water level, then display it on a LCD diplayer.....and when water level is in max lvl,stop water flow....and when water level is in min lvl, allow water flow...

any one can guide me how to start and how to design???need wat kind of water sensor....choose what kind of microcontroller chip,how to control the water flow......and so on.........

is ther any nice refrence on PIC that can help on this project?

thx...

[mister_e]

you really should consider the PIC16F84 as obsolete and never ever use it again.. well it's my opinion.

Look for something newer like 16F628a, 16F88 wich give you more usefull freebies in for almost the same price see cheaper.

For the PIC reference... after the datasheet, i ca't really suggest you something else, but browse the Microchip website, there's tons of app note there. Do a search within the forum for BOOK and you'll find some information

[Darrel Taylor]

Hi ckyz,

If all you need to do is detect the high and low levels in a tank, then something like these floats would do the job.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170007230942
$5 each.

However, if you want to display the actual level in the tank, you'll need a "Continuous" level sensor. Here are a couple examples, but these things are usually several hundred dollars each.
http://www.pulseinstruments.net/index.asp?PageAction=VIEWCATS&Category=1094

The idea is to bounce an ultrasonic signal off the water and measure the return time. Much the same as the little sensors everyone puts on their robots to detect obstacles. Here's one that might work, as long as your tank is less than 3 meters tall. Should be good for starters.
PING))) Ultrasonic Sensor
http://www.parallax.com/detail.asp?product_id=28015
$24.95
<br>

[Dave]

ckyz, Another cheep solution is to use a dip tube or bubbler and a pressure gage to measure the pressure it takes to full the tube before air comes out. This method is used for many types of level controls in liquid type media. The pressure is proportional to the level of the liquid so it can be calibrated to the amount in liters or gallons. Water is 1 psi per 2.307 feet of depth.

Dave Purola,
N8NTA

[blainecf]

Inside your gas tank, there's a continuously variable float sensor. New they're spendy, but from a junk yard - cheap!

They should read very easily using A/D, since they're nothing more than a volume control (potentiometer) with an arm on it. Speaking of that, you could make your own using a volume control, a piece of stiff wire, and something that floats.

regards,

[ckyz]

ermm....if for u r doing this project....how would u design it ya??

Darrel Taylor:ya...i wan to meassure the level na ddisplay it....and i think the ultrasonic sensor is nice. ermm...is ter any more cheaper sensor like tat??

Dave:the system u notice seems complicated.....how does it work??i really new on it and dunno much.....

blainecf:what is tat variable float sensor??

ohya...is ter anybody know how a car system meassure the fuel tank har??

thanks for help......