Help required regarding my project

Thread Starter


Joined Jan 9, 2007
Hi friends
I am Raghavender doing my final year engineering.I am working on a project entitled Microcontroller based elevator system.I am searching for information about optical limit switches which i am using to sense the floor level.
So pls help me out in sending some information about this component.
I also require your help in programming the AT89C51 in developing my project.
Thanking you in advance


Joined Nov 1, 2006
Hi, welcome aboard! A good source for industrial/commercial duty photecells & optical sensors which can be used for PLC inputs is Banner Engineering; I've worked with them for years in the shop. In the US they're available in many electrical supply stores.

If you can't find programming assistance here try the programming forum on the site. The only programming I've done is on Allen-Bradley & Modicon PLCs.


Joined Nov 1, 2006
I had another thought about using a mocrocontroller to run an elevator. No problem, provided this is limited in scope to being a college or hypothetical project or an elevator that's never occupied by people. Before this can ever be used in the real world for people [at least here in the US] you need to check all the federal & state laws & regulations regarding elevator controls. The approval & licensing process will probably be challenging. Like OSHA, in the workplace, they're pretty rigid in order to keep them safe.

What would happen, for instance, if the computer froze & the motor or drive enable output failed to turn off? I know that Allen-Bradley didn't & probably still doesn't recommend the use of their PLCs to operate press clutches because of the possibility of serious injury in that event.