can someone guide me about how to select a reed switch for atmega16 microcontroller.there are reed switches with different specifications and i am confused which one to use,how to know specifications like current and voltage of reed switch which will b suitable for atmega16??

 

Any reed switch will do. The ATmega16 does not care which reed switch you choose. It is the circuit connected to the reed switch that matters.

Edit: I assumed you are using the reed switch as an input to the MCU.

 

If, on the other hand, you are DRIVING the reed switch with the MCU, you need to select one with a coil resistance that will not overload the output of the MCU or plan on using some sort of driver to the coil. Also, don't forget back EMF protection.

 

I've used reed switches to microcontrollers before and had a problem with bounce.
So you may have to hardware or software debounce (I chose hardware).
There's a recent thread about debouncing.

 

If, on the other hand, you are DRIVING the reed switch with the MCU, you need to select one with a coil resistance that will not overload the output of the MCU or plan on using some sort of driver to the coil. Also, don't forget back EMF protection.

what you describe is not a reed switch, it is a reed relay

 

Since the OP was concerned with voltage rating, I ASSUMED (wrongly) that he/she was referring to the coil, since the voltage rating of the switch element of almost any reed SWITCH would be much higher than the voltage allowable as an input to his MCU.

 

m using simple glass enveloped reed switches to provide input to microcontrolle.can reed switches directly be interfaced with microcontroller atmega 16??
link:http://shopping.rediff.com/product/reed-or-magnetic-switch-small-spst---5-pcs/10822430
(m refering to this switches)
thank you for your replys

 

I would connect the reed switch between the input pin and GND.