Laser Tag Add-On Project

Hello Everyone,

Although I have done many projects with Arduino, I consider myself a newbie still so forgive me if I don't understand everything :/ This is also my very first post ... But anyways I have existing Phoenix LTX guns as seen on this website. http://www.ggaub.com/ltag/images/equipment/phoenix-ltx-pr-shot_big.jpg

I want to be able to capture the signal being output from the guns, recreate the signal on the Arduino, and finally output it to "tag" a different gun.

So far I have created many different codes so I am not sure which to put up. So far I have two different Arduino set-ups; a receiver and emitter. For my receiver setup, I broke open an old computer remote receiver and put the npn transistor looking detector in a basic 5V or GND switch setup. 5V goes to the collector, I pull out the voltage at the emitter side which also connects to an 11k resistor going to ground. Using this I was able to get

The top graph is the incoming signal from the laser tag gun, and the bottom signal is my recreation of the signal using a bunch of delayMicroseconds() and digital writes. I noticed that these graphs match with previous work from a laser tag site. http://web.archive.org/web/20090304155723/http://lasertagparts.com/ltto.htm

So my emitter setup results were seen in the graph above. My emitter setup is a High-Output Infrared 940nm wavelength LED connected in series through 200 Ohm resistor to a digital output pin. I would post the code, but it is honestly just a bunch of delayMicroseconds() with high and low digital writes. But I can't get the Arduino to "tag" the other gun.

I have read that you need to have a carrier frequency of 38kHz and I feel that this is the reason my setup isn't working. I have read many other posts about carrier frequency but I can't seem to get it to work using their methods of changing the clock timer and/or using tone(). I was wondering if you all had some guidance for me on how to go about doing this or if there could be anywhere else specifically that I have gone wrong.

Thanks

Hi,

While the graphs look close, I'm not sure if they've got the accuracy you need. Ladyada has a great tutorial that explains how the 38kHz frequency works, here http://www.ladyada.net/learn/sensors/ir.html which includes code snippets for how to listen to, and reproduce iR command sequences. While you've not included your sketch here, perhaps you can lift something from that tutorial to get your project going?

Of interest in that tutorial is that the standard methods for reading and writing to digital pins aren't fast enough to get accurate iR commands reproduced, so they use low level calls to access the ports.

Cheers ! Geoff

This article was very helpful! Thank you, I feel that I understand PWM much better now and should be able to play around with this code to implement my own signals.