regarding tyre pressure.

i want to know which sensor should i use for measuring tyre pressure real time in my gokart(type of open wheel car) project?(i am using arduino uno board)...pls help asap

Have a look at sensors used in cars and how they work

well... You can get pressure sensors and they are fairly easy to wire-up to an Arduino but they tend to be expensive and I'm guessing you want continuous real-time monitoring like [u]TPMS[/u]?

Building something like that, that's small, wireless, and has a long battery life would be a "challenge" and it would probably cost more than buying a system and it probably wouldn't work as well.