kad

Tried that...but not able to distinguish whether the person is entering or leaving as both the beams get obstructed when either of the two happen...could you please suggest me an idea...please help :(

Is there any sensor which detects the direction in which the person is moving? That is it should produce a pulse if the person is moving in one direction and a negative pulse if he moves in the opposite direction..please help

I'm plannig to do a project that includes counting the number of people entering and leaving the room through one door..For this i want to use 2 light beams simultaneously to count the number of people entering and leaving the room Now if a person enters your room he will pass by beam 1 then beam 2, if he leaves it then he will pass through beam 2 then beam 1.. so when the person enters the room beam 1 gets obstructed and generates a pulse which is given to a counter thus the ppl entering is counted.. and when the person is leaving second beam is obstructed and is given to a different counter to count the no .of ppl leaving ... But the problem is that when the first beam is obstructed the second beam should should be deactivated untill he crosses the second beam while leaving(as the second beam shouldn't count when the person is entering) so can u suggest me some idea for deactivating the second beam only for few seconds...please help

I want to build a digital alarm clock which gives an alarm for a set number of times in a day i.e, we should be able to give any number of input timings for the alarm to ring (like a school bell set at the end of each class). Could someone please help....