What is inside a IR reciver component?

[stig]

..as I understand it a modulated IR reciver is a photodiode and a IC that does some comparison or encoding..

anyone know if this IC function can be replaced by another IC, and then be connected to a larger number of photodiodes? I want to use a larger number of cheaper IRphotodiodes instead of the more expensive IR modules for object detection on my robot..

datahsheet on a typical reciver.
https://www.elfa.se/pdf/75/07520596.pdf

very greatfull for any help :roll:

 

[akg]

..as I understand it a modulated IR reciver is a photodiode and a IC that does some comparison or encoding..

anyone know if this IC function can be replaced by another IC, and then be connected to a larger number of photodiodes? I want to use a larger number of cheaper IRphotodiodes instead of the more expensive IR modules for object detection on my robot..

datahsheet on a typical reciver.
https://www.elfa.se/pdf/75/07520596.pdf

very greatfull for any help :roll:

u can build IR detector using descreet components , but that will be 're-inventing the wheel' and also more expensive , since ur basic objective is object detection for robot.

 

[stig]

reinventing?, yes thank you

i would actualy like to reinvent it. I would like to build an array of photodioes or phototransistors instead of using a large number of IR recivers modules.

My idea was using a IC or Microcontroller to feed the diodes with whats needed, and then end up using only one ic and 10 or more diodes for saving money.

What about IRDA, can a photodiode be used for that purpose , or are all IRDAs using IrReciver components?

 

[DirtyLude]

Well, they really don't do any decoding, all they do is try and filter out IR that's not pulsing at their tuned frequency. You don't really need this function if you're just doing range sensing, but it does help filter out ambient IR. If you are checking all these photosensors with a microcontrollers ADC, you can build the functionality into your uC's programming.

In the range sensing test rigs I made up, I just used a standard IR LED and photodiode with logic in the IC to compare the photodiode readings when the IR LED is on, and when it's off. You can also build in logic based on the abient light reading, as higher ambient IR will reduce the effectiveness and therefor distance reading.

IRDA uses matches transcievers, which are not usefull for this kind of thing.

 

[stig]

Thx

I am a newbie in micro-controller programming. I have been trying to use photodiodes and phototransistors as simple light detectors, but without success, Photo-resistor was easier.

But in this project my goal is to detect a oscillated IR signal that is from a remote beacon using an array of sensors, is it possible to do it the way you suppose? Without using the same MC as IR-source and IR-detect?

What circuit shall I use, only a resistor and photodiode (dark one) into the I/O of the MC?

And what is the code examples /functions i shall investigate for Basic?

 

[akg]

Re: Thx

But in this project my goal is to detect a oscillated IR signal that is from a remote beacon using an array of sensors, is it possible to do it the way you suppose? Without using the same MC as IR-source and IR-detect?

"oscillated IR signal " -> modulated IR ..?
the above explained system can be done, but why u need an array of sensors for detecting a beam.? , and is this ur excat requirement?

 

[lord loh.]

TSOP 17xy

Have you checked the TSOP 17xx series datasheet?

They have a nice block diagram. And seem to do exactly what you want.

 

[stig]

esyer to use the IR recivers

modulated IR is the term yes.
I will stick with the ready packed IR recivers, when i look at the block diagram I see that its a lot of functions involved, and that it will turn out to be less minimal design, and more expensive.

Another question is if I want to build a dekoder wheel for my robot, using reflektive technic, will a IR diode and a photodiode do the job? I still cant find any redings from a photodiode when I look for HIGH or LOW, do I need a capasitor or something? :roll:

 

[stig]

i was thinking of covering the hole robot thing..

I was looking for a way to use a hughe amount of sensors. And the LED type packaging is very nice to poke out of holes, The IR recivers are allvays square and 90´...

 

[akg]

Re: esyer to use the IR recivers

Another question is if I want to build a dekoder wheel for my robot, using reflektive technic, will a IR diode and a photodiode do the job? I still cant find any redings from a photodiode when I look for HIGH or LOW, do I need a capasitor or something? :roll:

yes .. u can.. the PD shld be reverse biased and o/p connected to an (very)high impedence amp like TL071 as buffer then amplify that to get a useful reading.
or use a reverse biased PD in the base drive of a high gain transistor.