Help with Capturing Infrared Signals?

Hi, everyone!

I’ve got a new project going that’s a slight bit outside my area and I’m hoping someone would be willing to share their expertise on this…

***The short version: I have an infrared laser that fires, and I’d like to pick up whenever the infrared laser is detected as a digital signal. So if you imagine me firing an infrared laser at the wall, I want an infrared camera aimed at the wall to detect when the laser is present on the wall and store that signal somehow, e.g., running it to the computer via Teensy or Arduino. The issue is the hardware & interface, which I don’t know enough about.

Is there anyone in the shop with this kind of knowledge that would be willing to spend some time discussing what that hookup might look like?

***The long version: I study how police make deadly force decisions and we have built a shooting simulator to study this. Officers interact with video scenarios displayed on a projector screen, and fire a modified handgun when they identify a deadly threat. It’s kind of like an arcade shooter game but serious. You can see an example here: https://www.youtube.com/watch?v=Le8zoqk-UVo

Right now the setup is that when the officer fires the gun, the trigger depresses the lever on a microcontroller inserted into the handle of the gun. That microcontroller is hooked up to the computer via Teensy. This setup works great, except when it doesn’t --like when the microcontroller gets knocked off-alignment.

I’m hoping to make the setup more stable by using the infrared signal that fires from the gun. The barrel of the gun has an infrared laser inserted into it that fires when the trigger is pulled, and if I have an infrared camera pointed at the screen I should be able to detect the presence of that camera. I know that other, professional systems (like the ones that cost $100k) use this: goo.gl/Ca6pyn to accomplish this. But this is just too far beyond my wheelhouse to understand what I need to do with a Teensy or something like it to capture that signal.

I would so appreciate any help from knowledgeable people on this! I can meet most anytime. Don’t worry… I can work on this without bringing the guns into the makerspace!! The infrared barrel is removable :slight_smile:

Hmm. I think you’ll actually be looking at some sort of open CV style thing here with a camera and all. @michael has some experience dealing with infrared stuff so maybe he has another idea.

You might be able to get away with an infrared receiver, but I’m going to bet the infrared laser pointer on the gun is too directional to trigger one.

Interesting problem for sure. I’m sure there’s a way!

I have used the LCC Simulator, some 10 years ago that is similar to this. I recall that it even knew exactly where the bullet would have hit.
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For a DIY system; either OpenCV or Machine Vision will do the location. https://www.sparkfun.com/products/14186 is a OpenMV camera. To use full OpenCV would also require supporting the Computer. Such as a Raspberry Pi and give you more flexibility of what you trying to do. However, the OpenMV system, is a complete system. So no need to worry about the OS and such. I am not sure how IR sensitive the OpenMV camera is. With OpenCV you can find a camera that fits. Likely it can. It may just need the IR filter removed.

It is not clear to my why or how a Teensy fits on a Trigger and falls out of alignment. I would expect there is a pair of wires that run to the trigger and when pulled they short.
I believe simulator guns have been modified so the contacts are internal the gun.

They make a drop in bullet that fires a red laser dot…


I wonder if this could be useful as well.

Hi, Michael:

Sorry I wasn’t clear – the microcontroller is connected to some cables that threat out the bottom of the gun and connect to the Teensy, which is stored in an enclosure external to the gun. The Teensy sends out a signal to our software (PsychoPy, python-based) which reads when the gun is fired.

Location would be even better to know, and if I can set myself up to eventually get that information great – but right now it isn’t my primary concern.

Is there a chance I could chat with you in more detail sometime next week? It would be great just to get an overview of how all the parts would fit together and what needs to be done to make it work.

Thank you!

Yeah, this is similar to our setup (we use one of these: https://www.dvorakinstruments.com/products.asp) but the downside to the product you linked is that there is no recoil. That reduces the realism quite a bit and officers don’t love it.

But, it might be useful to think about how they capture that info and whether we can do something similar, so thanks!

Joe