find out when someone walks though a door and in witch direction???

[FlashCreated]

Hi,
Can anyone tell me or give ideas on how to find out when and in witch direction someone is walking thought a door, i then need to output 5v to one of two circuits depending in witch direction the person has walked through the door.

Forgive me and ask questions if i am to vague.

Thanx in advance!!!

FlashCeated

PS: i do not want to use anything involving the door handle or any thing like that i jut need to know when said person goes from outside to inside the room.

 

[davenn]

Hi,
Can anyone tell me or give ideas on how to find out when and in witch direction someone is walking thought a door, i then need to output 5v to one of two circuits depending in witch direction the person has walked through the door.
Forgive me and ask questions if i am to vague.
Thanx in advance!!!
FlashCeated
PS: i do not want to use anything involving the door handle or any thing like that i jut need to know when said person goes from outside to inside the room.

2 infrared beams across the doorway. if the beams are a few inches apart then one
will be broken before the other and that can indicate which direction the motion is

Dave

 

[FlashCreated]

thanx for your reply dave, sorry i should of said hat i tryed that already and i could no get it work because the ir led couldn't go that far...

can anyone suggest something else???

thanx in advance!!!

FlashCreated

 

[(*steve*)]

Lasers,or focussed and modulated IR beams. Across a doorway is nothing. Consider that your average remote control works many metres from a TV even if it is pointed in a completely different direction.

 

[davenn]

thanx for your reply dave, sorry i should of said hat i tryed that already and i could no get it work because the ir led couldn't go that far...
can anyone suggest something else???
thanx in advance!!!
FlashCreated

As Steve said, infra-red LED's have no trouble shining across a decent sized room.....

if you cant get it to work across a doorway you must have wired it up wrong
show a pic, draw a cct or something to let us see what you did and see if we can help

Dave

 

[FlashCreated]

yer thanx i see your point... now that i think abut it i think i was only using standard leds, can you tell me where i can get some ir ones, i usually use radio spares... also i was using light dependent resistors to detect the light on the other side, will they work with ir leds???

thanx in advance!

FlashCreated

 

[Resqueline]

Old shop entrance bells used lamps & LDR's, with a lens in front of each. A real well focused beam LED should work well also. Beware of external light disturbance though.

 

[FlashCreated]

Old shop entrance bells used lamps & LDR's, with a lens in front of each. A real well focused beam LED should work well also. Beware of external light disturbance though.

year thanx but even if that does work (and i'm not sure it will given the obligatory position of the ldr in direct sunlight when i open the door, this, i know can be fixed but it's yet another complication...) were can i get a lens? Isn't it gowning to be be harder to setup and more expensive than if u were to buy than an ir led?

thanx though!

flashCreated

 

[Resqueline]

Leds or lamps doesn't matter, they have to shine across a distance - to the LDR's - outshining the sun. That'll take optics & shielding. Lenses can be had 4 free if you look.
But as mentioned there are more "sophisticated" methods, like frequency modulating LED's - and a photodiode receiver with frequency discriminating output channels.
The choice is yours.

 

[FlashCreated]

ok thanx! So isn't there another way like a loop of cable round the door to detect metal or a small radio receiver and a transmitter in my pocket... there must be other methods, no?

thanx in advance

FlashCreated

 

[Resqueline]

Of course, radio & radar detection can be implemented, but you referred to just "someone", not yourself equipped with something.. The choice is still yours..