smart IR proximity Sensor

[nikhilele]

smallest infrared proximity sensor

I want to build a smart IR proximity sensor.

Requirements

1>
3 feet to 5 feet of proximity sensing.
2>
No false alarm due to other IR remote controls
3>
Very low cost.
4>
small size if possible i have to do it using single chip.

 

[dika]

infrared proximity+555

check this out

h**p://www.electronic-circuits-diagrams.com/alarmsimages/alarmsckt19.shtml

1>to achieve maximum distance, adjust the angle between IR emitter and detector. but i'm not sure if the detector could sense to 5 feet. from what i've tried it could only sense around 3 feet.

2>to minimise external noise adjust the 555 oscillation frequency

3>don't use sharp if you opt for low cost. use photodiode

4>well it only use single 555...

hope that helps

 

[nikhilele]

3 feet is enough for me.
I have Tsop1738

One this more it should not give false trigerring with IR remote controls in the home

 

[dika]

i don't know on what frequency your ir remote transmitting but if it crossed around 30MHz then the url i gave is obsolete.

perhaps you want to consider using 567 instead of 555. use the phase lock loop function to minimize any interference.

hope that helps

 

[nikhilele]

i am trying different thing.
I am sending data serially and recieving that back
if the data is same is that i send then its a valid reflection.

 

[dumanmehmet]

Can it measure the distance 8cm to 40cm with 4cm presicion?

 

[nikhilele]

yes it was good enough...
just send some bit pattern and receive same back..
it will avoid many false triggering