Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

IR prox sensor

Status
Not open for further replies.

benleong

New Member
Hi there everyone, i'm new here and hope tht any1 could help me on my issue.
have u all heard about "bumper prox logic"?
i dunno wat it calls but wat i intend to do is to create a robot that can moves by itself and avoid obstacles.
http://www.schursastrophotography.com/robotics/irproxlogic.html
the question is i dun really understand da ir circuit that given in da link above.
can any1 help to explain or give me any other circuit that r more helpful?
 
benleong said:
Hi there everyone, i'm new here and hope tht any1 could help me on my issue.
have u all heard about "bumper prox logic"?
i dunno wat it calls but wat i intend to do is to create a robot that can moves by itself and avoid obstacles.
http://www.schursastrophotography.com/robotics/irproxlogic.html
the question is i dun really understand da ir circuit that given in da link above.
can any1 help to explain or give me any other circuit that r more helpful?


You can read my tutorials about Infra red proximity sensors.. there are some simple solutions...

**broken link removed**
 
Great little circuit ika, but how does the sensor LED pass enough current to even turn 'slightly' on? Wouldn't the high input impedance allow only a minuscule amount of current to pass through the "detecting" LED?

Finding the right bias point must be a drawn out process, I'd imagine the downward pressure of a screwdriver would be enough to put it out while tuning :confused:

Just thinking out loud :eek:
 
gramo said:
Great little circuit ika, but how does the sensor LED pass enough current to even turn 'slightly' on? Wouldn't the high input impedance allow only a minuscule amount of current to pass through the "detecting" LED?

Finding the right bias point must be a drawn out process, I'd imagine the downward pressure of a screwdriver would be enough to put it out while tuning :confused:

Just thinking out loud :eek:

Well, that's what it seems, but in practice, it's relatively easy to tune..

the problem of this sensor is that it lacks effective ambiant light immunity, but it's nice for beginners and dosen't require too much special components...
 
why not use a phototransistor in that circuit? I think it would have a much higher sensitivity than an LED.

In general, that circuit seems like it would be susceptable to interference (sunlight springs to mind).

I would be tempted to use a standard IR receiver like the tsop11xx line. it requires pulsed output modulated to the receiver's carrier but it should be pretty good at rejecting interference. relatively cheap, too. transmitter can be done with a dual timer (lm556, for example) or an ultra cheap uC. You will need to shield the transmitter from the receiver, by the way.
 
Last edited:
philba said:
I would be tempted to use a standard IR receiver like the tsop11xx line. it requires pulsed output modulated to the receiver's carrier but it should be pretty good at rejecting interference. relatively cheap, too. transmitter can be done with a dual timer (lm556, for example) or an ultra cheap uC. You will need to shield the transmitter from the receiver, by the way.

Exactly, here's an example (from a few years ago) on one of my websites.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top