How to detect gun recoil?

Hi everybody. This is a project I was working on for a bit, but then I hit a road block and abandoned it for a while. I'd like to get a working prototype going, so any input on feasibility would be much appreciated! I'm still pretty new to Arduino, FYI.

In short, I would like to attach a sensor to a firearm and detect when the gun is fired. Kind of like an odometer for guns. What type of sensor would I need for this? I was trying to get it to work with an ADXL193 breakout from SparkFun, but I think that this sensor may have too wide of a range (+-250G) and too low sensitivity (8mV/G) for my requirements.

That is the basic function that I want, and possibly a calibration setting to avoid false values (i.e. dropping the gun). Ideally I would want to be able to attach it to guns of different calibers and calibrate it for that particular firearm.

Any tips? Thanks!

Do you want to measure how much recoil, or just that the gun has fired. I would think a microswitch placed in path of gas chamber discharge would do it.

The only place I could think of mounting such a switch is on the brass deflector, which gets hit by brass and gas non-stop. A switch wouldn't last long there, and I'm not sure how I would mount it.

Looking forward, I would also like to design this to be as user friendly as possible. Keeping the device in an enclosure that could be mounted on any gun with an accessory rail is important.

You can try to attach a little micro switch the handle that checks to see if the hammer touches it. Pull the trigger, hammer goes back, which touches the switch and gun is fired. You could also check to see if the hammer is pulled back manually with a timer.

Another solution is a IR beam that checks to see if the barrel goes back, (can also be done with a switch).

Another solution which might not be the best, but, you can fit a small tactile button behind the trigger and adjust it to where it would actually fire the gun.

djm227: Keeping the device in an enclosure that could be mounted on any gun with an accessory rail is important.

Will all the guns be the same shape/size?

Pistol or revolver - or other?

Focusing on rifles right now, and yes they will almost all be the same size and shape.

A switch is definitely a foolproof way to do it, but is there no way to accomplish this with some type of shock sensor? Once I incorporate a switch into the design, I'll probably have to run wires and mount devices to other parts of the gun which I'd rather avoid.

That is the basic function that I want, and possibly a calibration setting to avoid false values (i.e. dropping the gun). Ideally I would want to be able to attach it to guns of different calibers and calibrate it for that particular firearm.

This is a very tall order. a 22 has much less recoil than if you dropped it. the other requirement

Keeping the device in an enclosure that could be mounted on any gun with an accessory rail is important.

you want to make this as a stand-alone device that is only mounted, not connected to the gun ? that means only motion or sound, or both. any recoil could be duplicated by dropping the gun. you might need to add both recoil and sound.

I would think you would want the unit to sleep all the time, then generate a signal upon recoil. not sure if the noise follows the recoil and if it does, how close they are to each other.

A simple pezio buzzer might provide a distinctive signal on firing. Although you'd have to be able to determine between firing and casing discharge.

At a trade show, I once spoke to a salesman from a weapons training company. Their system used a barrel insert that detected both the shock and the flash of a blank being fired to trigger a coded laser pulse. Originally, they had just used a shock sensor, but had found that when squaddies ran out of (blank) ammunition, they could point their weapons in the right direction and hit the butt with a rock, so allowing them to remain in the "fight".

Thanks for the feedback everyone. It seems like the best way to do this would be a switch instead of a shock sensor. Now I have to figure out the best way to integrate a switch into an existing firearm platform.