Advice wanted regarding IR transmitter and Receiver

[3dhelidude]

Hi All,

I'm looking to build an IR transmitter and receiver set up for the following requirements:

Needs to transmit and receive to approx 7 - 8 meters in sunlight (adjustable distance would be good)
2 - 3 Receivers to be ground based in tubular housing and receive IR signal from directly above and should provide audible tone with adjustable volume if possible.
IR tx (6-9 volts) will be always on & mounted under a remote controlled helicopter so that when the helicopter is directly over the receiver an audible noise such as a buzzer is heard.

The setup will be mounted in the same fashion as https://rcjapan.net/k-u0026-s-discontin ... only-p-570

Any advise on kits or circuits that could be used would be greatly appreciated.

Matt

[pebe]

The link you give shows that the item has been discontinued.
Can you give more information on the item and on what it was supposed to do?

[3dhelidude]

This is device to hone precision skill in remote controlled helicopters. As you look at the picture in the link, the 2 flags that contain the IR receiver and are placed 10 meters apart outdoors on a specific marked out area, the IR tx is fitted to the underside of the helicopter with the intent of the pilot to hover the helicopter directly over one flag at a time for a minimum of 2 seconds. If the helicopter is directly over the flag as is a requirement in the competition, an audible tone is heard to indicate that the helicopter is directly over the flag.

Hope that helps,

Thanks in advance

Matt

[pebe]

I think you can do what you want with a simple IR link. The helicopter would transmit an IR signal and that would be picked up by an IR receiver at the bottom of the tube.

To minimize the effects of sunlight, you need to modulate the IR beam at a high frequency, such as 38KHz. In the helicopter a 555 timer could generate the frequency and power an IR diode facing downwards. You could use this one:

http://www.bitsbox.co.uk/index.php?main ... ts_id=1371

The receiver would use filters to accept only a 38KHz signal by filtering out sunlight and interference. You could use this one:

http://www.bitsbox.co.uk/index.php?main ... ts_id=1377

It gives a logical output that you could use to switch some form of audible warning. You can see from the datasheet that is has a max range of 35mtrs when the transmitter diode is passing 250mA, but as you only want 7 - 8mtrs you can cut down on the IR diode current - very helpful when you are running it from your helicopter batteries.

If you want more details I'll be happy to oblige.