Long range (10 meters and up) IR transmitter and reciever

hi everyone,

I built the transmition circuit (940 nm) that works with 1.5Khz (with 555 timer chip) . now i having hard time to build the reciever for long ranges (10 meters and up). can someone please give me directions or diagram how to built this circuit?

which led and photodiode do you reccomend for this range? does the frerquency that i have used in the transmiter (1.5Khz) is good for this range?

thanks alot!

Show the circuit you're using.

Remote controls usually use a 38kHz carrier, I guess you're using a lower frequency to be able filter the signal for more noise reduction. Please show the circuit schemata you're using. How did you plan to demodulate the received signal? In software or in hardware?

which led and photodiode do you reccomend for this range?

Why did you fix the wave length if we have to suggest the hardware to be used? Is this for a remote control or do you install the hardware on fixed positions (so you could use more directed/focused optical components)?

When i thinking about it, i'm using an arduino so i can modulate the led with just a simple programming. so showing the transmitter ciruit is not relevant anymore.

i'm planning to demodulate the signal with arduino code.

i pick 940nm because i need something to start with.

the application is for two tiny cars (one is the transmitter and the other is the reciever) , one car will send data and the other will be able to recive it.

thank you pylon!

i pick 940nm because i need something to start with.

Don't you think that defining you think it should be IR would have been enough detail?

the application is for two tiny cars (one is the transmitter and the other is the reciever) , one car will send data and the other will be able to recive it.

That means the sender and receiver must have an opening angle of 360°. With such circumstances a reliable transmission using infrared light over 10m requires quite much power. If you say "tiny cars", do you really have enough batteries on them to power such a system? Are you open for alternatives (radio transmission)?

Sorry, thats the datashit of the LED and the photodiode

LED: http://www.4project.co.il/documents/doc_391_435.pdf

Photodiode: http://www.4project.co.il/documents/doc_391_436.pdf

in my project i dont need field angle of 360°. narrow angle will be just fine.

Use a lens or parabolic reflector on both ends. The better the focus and narrower the beam, the farther you can transmit and receive.

Thanks.

But i dont know how to start building the reciever circuit. i saw some tutorials that totaly confused me.

can someone guide me how to build this long range reciever?

thanks alot.

in my project i dont need field angle of 360°. narrow angle will be just fine.

Specify narrow angle!

If you tell us a bit more about your project we might be able to suggest you better solutions. With the hardware you linked to you probably get problems at a distance of 10m but you can try it, I never used that combination. With these cases you cannot use parabolic mirrors to enhance the transmission distance.

not a complicated project. like i said before- two tiny cars one of them is the transmmiting car and the other is the reciever car. the reciever will demodulate the data from the transmmiting car by the arduino code and functioning exactly like TV reciever. the transmmiting car sending modulated data from arduino mini also by a code. the led has to be narrow angle - 5 ° and powerful.

sorry about the lack of information i have some trouble with my english :blush:

Do you already have the linked hardware and can try with that? Do you have meters to see what signal is arriving (scope)?

You can use high power IR LEDs but I have some doubt that your mini cars have batteries that are powerful enough.

You haven't told us why it has to be infrared light and cannot be RF modules for example.

You should also specify what "10 meters and up" mean. In this case the maximum required range is more important then the minimum.

Define "tiny cars". How big is tiny?

Is all this supposed to work inside or outside? Is the IR coming from the Sun going to be a problem?

Why not demodulate in hardware? There are cheap existing solutions, packed with an amplifier, just plug and play.

This type of circuit may help...

http://www.analysir.com/blog/2013/11/22/constant-current-infrared-led-circuit/

You might be better off investigating the use of an standard 38kHz IR receiver and you should be able to get 10m without too much current.

Try using an IR LED like the TSAL6100, which has a narrower angle.

Narrow angles with mobile objects seems to me like a bad combination. Are you really sure you can safely assume the receiving car will always be within a 5-degree window of the transmitter? That means they'll have to be in a straight line, one in front of the other, for transmission to succeed.

I agree with pylon. You should probably consider using RF instead of IR. If IR is not negotiable for some reason, then I also don't understand why you want to demodulate the signal in software. Are you sure that's really a requirement? A tuned hardware demodulator should perform better than a hacked software one in nearly every case.