I think air pressure would have more initial torque however, so would possibly give more of a realistic sensation (jolt not shove). Certainly, this was the method traditionally used at places like Disneyland etc to simulate gun firing, and it was also used by one of the Virtuality systems that had a shotgun with air powered recoil.

I think air is probably a good way to go for a wired system (however, would also be noisier which can be a concern), but for a wireless system a solenoid would have the advantage being able to be made more easily portable.

I have the TN Games 3rd Space Vest. It is no joke. It really does hit hard.

Sure, you could have a pneumaticly operated system. Like I said before, strong haptics needs a strong power source. It doeesn't need to be electrical. You could run it from a paintball gas canister, you could even strap a tank of propane to yourself and have it ignite in the controller.

I am trying to make a device that can decide when to fire the recoil mechanism. What that mechanism is, is really up to people to decide for themselves.

Cyber, in the driver you hope to make, will it have suport for devices such as TN vest? It looks like a nice piece of hardware, but as you know it is usless without software. I don't currently have the skills to include usb in my device, but if you can emulate a serial port over usb I can give you pretty direct control of the output.

Er, what?

Looking forwards to seeing you finish this driver bobv5. I think your idea of using the sound + trigger pull to trigger the effect is the best so far in terms of usability with all games.

@bobv5: Yes. I plan to support force-feedback devices with my driver. This was actually one of the main reasons I wanted to do this. Ideally, I will support consumer devices like the TN Vest, Novint Falcon, etc. and then provide an API for people with more exotic and/or DIY devices. But again, I am in the very early research phase right now. It may be months (or longer) before I actually have something usable.

Aphradonis- I'm not saying it is a good idea for someone to build with junk around the house, but if you have access to machine tools and know how to do the maths, it could give a very powerful, fairly cheap recoil.

I hope to get something working as soon as possible, but at this time of year I don't have a spare penny to go towards my projects. The good news is that I have an SMD rework station in the post, (Thanks Mum ) so will be able to make the boards far easier, and use components that were previously unavailable to me.

Cyber, I'm in a similar situation, I have the hardware and firmware working in a simulator. I hope to have a working hardware prototype early next year. I understand that for your driver haptic feedback is not a priority now. I'm not great at software, what would your driver be expecting from a USB connected haptic device? I know I really need to read up on USB protocols, but far too busy at the moment, so any vague description would be good.

To be honest, I haven't thought about it too much. Still have a lot of ground-work to do first. The general idea would be that the driver would provide an assortment of output values, and there would be a C++ API that would give you access to these values. For an FPS game maybe there would be one floating-point value for the gun recoil. For example, the number 0.5 would indicate a medium level kick-back for a pistol, while rapid values of 0.3 could be for a machine gun. I could also find a way to indicate what type of gun was used, but this would be a little harder and probably would need to be done on a case by case basis for each supported game. Again, I don't want to hype this too much, but I am working on it.

Quick update, recievied the chips for the first prototype today. Will have to see if I can find time to sneak off to the lab.....

Any updates on this?

Hoping to get some pcbs made soon. I need to make a small change to the board layout, then I will have to wait untill I can get some time with the equipment. Hopefully sometime this month.

Awesome! I have this gun on the way: http://www.amazon.com/STAR-Dragon-AEG-A ... B00547O6O0

Looking forward to building a nice tracked gun, hopefully with whatever you figure out.

nice choice Palmer, i can see an analogue stick and some buttons going nicely into the forward grip of that odd looking gun

Palmer, would you just want the pcb or a complete system? The solenoids I am using are designed for 24v. I have no idea how they will perform on whatever voltage that battery pack you are using provides. (18v max I think?)

The output stage is quite robust, (about 30w max for each solenoid, designed to control two independantly). I can make it stronger if needed, but if people want it stronger I need to know soon.

It is too much hassle for me to design a circuirt that can be electronically linked to the trigger on peoples controllers. It will need to have an extra microswitch installed which is opperated by the physical trigger. The reason for this is that one person might use a wiimote, the next might use sony stuff, the next might use something i have never heard of. They are not compatible at the level my circuit works at.

I also have a few other ideas for this, which I have already designed into the hardware. For example, I plan for the reload button to be activated by pulling or pushing a physical magazine. This action will make a small activation of the solenoids. Just enough to feel like a mechanism, rather than a button. (optional of course, but I think it is a good idea)

I can step the voltage up no problem, so no worry about that. A complete system is probably best, if only so we both have the same hardware. Better for testing! As far as power, stronger is better in my book.

So, your circuit will need a sound input, a microswitch for the trigger, and 24v for power?

I can provide enough force to break bones, if you have the cash.....

My circuit will need a stereo sound input, a switch for the trigger (plus other switchs for reload etc if you want that stuff), and the voltage that the solenoids need. The solenoids I am using need 24v. I havent actually tested them mounted to a gun yet, but they are about the biggest that could be used without needing a stupidly huge battery.

Heh, use your own judgement in regards to force, then. I am planning on a handgun and a rifle, so I would be interested in two units.

Reading up on solenoids, it looks like I might not want to have them drawing from the same power supply as my more sensitive gear, so I will probably get a cheap high draw ni-mh pack to run them.

I have designed the circuit to minimize the noise that gets passed to other components on the same supply, but that stuff is basically voodoo. A seperate battery for haptics is not a bad idea, but if I have done my job properly it won't be needed. (I'm learning this as I go, so it is possible I did not do my job properly.)

Go to a thrift store like savers or a garage sale and get yourself an electric nail/stapler gun aka brad nail gun. Take it apart and solder together the "wall surface detection switch" wires and remove the magazine. Connect to Wall AC and fire away. Dead simple, good kick, and no worrying about sourcing a solenoid or designing driver circuitry.

That would not work with a battery pack, though, which is what we are trying to accomplish.

Ah, sorry I didn't read through the entire post. I would opt for something like a autohammer then: http://www.sears.com/craftsman-11818-ne ... 911818000P

That or a cordless hammer drill on the hammer setting.

The advantage of the two I listed above is they use a motor and cam to generate the linear "shock" so I believe that would be more power efficient.

I think that using a DC solenoid to get a good kick would eat up a lot of battery life.

Firing the electric nailgun I hacked on rapid fire caused the lights in the room to flicker.

Yeah, a geared motor system has a lot of advantages. That is one reason I am ordering that airsoft gun, going to mess around with using the firing mechanism (Quality, all metal!) for recoil. The disadvantage is a small lag between pulling the trigger and the first kick, and less flexibility in terms of how the recoil feels for each weapon.

Something like this?

http://youtu.be/IXHUFScbcFM

Yes, something just like that.

I may very well end up using something like that for my rifle, but a solenoid might end up being the better option for a handgun. Only way to know for sure is to experiment! Great idea on the autohammer, though, that never even crossed my mind. More brains means more ideas means better VR!

I purchased it to test it out, the thing is almost too quick (3600rpm or 60Hz) and the stroke is very short.
This video gives a good demonstration:

http://youtu.be/sDu6LIj5LFI

All very good ideas, but the whole point I think for using a sound activated control circuit powering a solenoid is so you get the various power and frequency of the different weapons kick back while not needing any special drivers to make it work (making it console compatible too), but I guess how important this is depends on your setup.
I like the look of that electric air-soft gun as an easy option for a non solenoid (non variable force) based setup, all the hard work is done for you, having semi auto, burst fire and full auto modes on a selector means that you could wire micro switches to the selector and have it switch your weapons/weapon mode in game depending on game (i.e. in battelfield you could have the selector automatically change you machine gun between burst fire and full auto in game) I guess the harder part would be cramming the buttons and analogue sticks in there for the controls.

I think you might be looking at "sound activation recoil" from a 30 thousand foot view. The devil is in the details, are you looking for a specific frequency (sound signature)? If so, you need to filter out all the other ones. If you use a hardware filter, you cannot change the pass-band frequencies after you build the circuit (easily) so a guns that has a different pitch will not trigger the recoil. You could run a digital filter but that is even more complex. If you use the amplitude to trigger the recoil (gun loudness) then you have to make sure that your own gun is much louder than all the other stuff going on in the game like explosions and other player's guns firing nearby.

It would be relatively much less complex to look at the trigger switch and run a relay to a I/O pin. You won't know which gun you are firing but you will know for sure that you are firing something.

It's also possible to scan the game's application memory space and figure out when you are firing and what gun, ammo, health and other things are going on in real time but that too is a bit hackish.

"I think you might be looking at "sound activation recoil" from a 30 thousand foot view."

Not quite. Perhaps 5000.

"The devil is in the details, are you looking for a specific frequency (sound signature)? If so, you need to filter out all the other ones. If you use a hardware filter, you cannot change the pass-band frequencies after you build the circuit (easily) so a guns that has a different pitch will not trigger the recoil."

You most certainly can easily change the frequency. For example, if using a simple RC filter, a variable resistor can be used instead of a fixed one. Another option is a digitally controlled potentiometer. SOftware is not my strongest talent, but I can imagine some sneaky tricks can be pulled this way. Games generally dont include much audio at very low frequencies, so I feel only low pass filtering is needed. If this turns out to be wrong, high pass filtering can be dealt with in a similar way.

"If you use the amplitude to trigger the recoil (gun loudness) then you have to make sure that your own gun is much louder than all the other stuff going on in the game like explosions and other player's guns firing nearby."

The gun sounds are generally pretty much in the center of the stereo soundstage. MIxing the left and right channels gives virtual center at +3dB. Not a huge difference, but hopefully enough that to the digital section of the circuit, player gun sounds are usually the loudest thing. Even things at dead center in the virtual world will probably be further away than the player weapon, so make less noise.

"It would be relatively much less complex to look at the trigger switch and run a relay to a I/O pin. You won't know which gun you are firing but you will know for sure that you are firing something."

Absolutely. But I'm kind of a masochistic electronics nerd. It would iritate me that I knew it could be done better, and, well, the easy way is boring.

"It's also possible to scan the game's application memory space and figure out when you are firing and what gun, ammo, health and other things are going on in real time but that too is a bit hackish."

Every solution to this problem is going to be a bit hackish. I think this would provide far better results, but it is beyond my ability to provide the PC side software.

My circuit will use a combination of a hardware low pass filter, a hardware mixer to reduce the level of sounds not in the center, software to look at the amplitude, and a switch to see if the trigger is being pulled. I think this is about as good as it can get while still remaining compatible with most software.

As another thought to throw out there, what about using noise recognition?
IE, pump the noise from the game through an algorithm that when you have pulled the trigger, only shoots when it hears the particular samples it has been 'trained' for.
IE, you could train it in all the different gunshot noises for a specific game, then it will only fire when it hears one of those noises.

Possible issues could be to do with other gunshots close by setting it off, but if you also matched on volume levels (you'd need careful control of volume levels) then it could still work.

I see that I didn't need to be as detailed in my explanations!

Yes you can set a passband by changing R's and C's but once you set it, it is typically permanent. If you want a moving passband, you still have to write the software to do it. I suppose you could look at the frequency spectrum for a repeating amplitude spike which would correlate to repeated fire. Maybe I am over thinking things.

I should point out that assuming the gunshot signal is the loudest at the center channel is only true if your looking view vector is the same as your gun aiming vector. This is true for almost every game so you should be fine but VR setups should separate the two axis so you can look left while shooting right. If that is the case then the initial center channel assumption is no longer valid.

If you have the ability to write software that will inject a signal into your audio line, why not use a dedicated virtual com port instead of an audio jack?

easiest way (to me) is to take apart your mouse and find the microswitch for the left button and run a relay that will trigger your secondary circuit.
That way when you press the mouse button to fire, ingame will shoot as normal but the relay will also trigger your recoil mechanism to fire at the same time.
The two circuits are isolated so you don't have to worry to much about the electronics.

I think he meant the software on the microcontroler. It is certainly a possibility, but I wouldn't have a clue how to program such an alogorithm.

Actually, I was referring more to a windows 'driver' that would listen to the sounds outputted and try to match them with samples.

However, this could be trickier to do on Windows 7 etc since I believe 7 etc only allows you to output to one device at a time.

@ mars, I have a similar idea/setup. I have a PS1 gun that has recoil. When firing single shots, it gives recoils once (cos you only pull the trigger briefly). When you hold it down, it gives continuous.
Now, the recoil might not match up exactly with the firing, but it definitely aids immersion. Nice to feel the gun rock in your hands a little when firing full auto...

I haven't seen one of those for a long time. I hear it's hard to find these days. Do you have a model number?

I can't find a model number, but its an 'Avenger Pro'.

I just realised its also got a foot pedal you can use as well. Its decent for the $20 secondhand I paid for it years back. Uses a motor drive of some sort (rotating cam or lever I guess) to work the slide.

http://www.amazon.co.uk/Fire-Internatio ... B00004TNN7

video: http://www.youtube.com/watch?v=dVCy9XGct8A

SOmehow I missed your post last time I looked at this thread.

The passband wouldn't have to be permenant, just pre selected. For example you might need 100-1000Hz for one game, but 500-2000 Hz for another. This could be adjusted with pots, or selected from a menu on a microcontroller.

As for you sugestion of using some sort of machine inteligence, (is that a good way to describe it? I don't know a better way), it is something I have considered. At the moment I want to get the hardware working with some basic version of the firmware. Software can be updated at anytime, hardware not so easily.

I have considred about software with seperate aiming and viewing. If someone is writing new software, they could provide a proper signal to a comport. If they can't or won't, the gun will still be relatively close and relatively central, and often still the loudest sound, so it shouldnt reduce performance too horribly. If somebody is pointing a gun behind them and firing, their disregard for the safety of their comrades precludes them from being rewarded with satisfying recoil effects.

I am not claiming the feedback will be perfect, but I hope to achive something that is pretty close when the player is more focused on what they are shooting.

Hi there. Palmertech, as you are an engineer working in VR and all, and seeing that you're looking for a nice gun to work with in this context, you may be interested in this link: http://www.virtual3dgun.com.

These guys are spaniards -just like me, incidentally, I don't know them personally nor did I know about them until just a couple of weeks ago- and seem to have been working on this project since 2006 no less, with what seems to be, at first sight, very nice results from both performance and ergonomic point of view.

They also claim that they don't use IR tech for their work. I copy and paste what one of the engineers had to say in response to some cynical user in one of their youtube video's comments: "No, it's not a trackir because it's not valid for the movement of the gun. Our system haven't point of reference in any site, for this reason it also function with a virtual reality googles without problems".

You may be interested in dropping them a line and share your thoughts about it, when/if they answer. I've been a silent reader of MTBS site and forums for a long time now and I'm curious about your opinion on this myself. I also happen to be a fierce enthusiast of VR -only platonically tho, for lack of resources, mostly- and everything that successfully increases immersion in gaming ine way or another. I once built myself, many years ago, a big, bulky Aliens-like machine gun out of a Sega Virtua Gun and a toy recoiled weapon, and the kick I got -no pun intended- from using it for playing Virtua Cop in my Saturn with the infinite machine gun cheat on was so amazingly enjoyable that fantasizing about a whole fleshed version of that using modern technology has always been a dream of mine.

Keep up the good work.

Man, I used to love playing Virtua Cop on the Saturn. Those were the days...

Weren't they? I have to admit, however, that for me, 'It' all started with Operation Wolf. Everyday during lunch break in high school I went to the bar next to it and drop my spare quarter into that Magic Thing that made my spine tingle every single time my ears catch the familiar tune and the affected voice: 'OperAtionn InIciAtedd... rEscue ALLLL hOstagessss!!!!!!' . The rainy november day that my mom picked me up from school and handed me a copy of the C64 version that those devils at Ocean perpetrated -half my childhood lost between the four walls of my room because of those cunning basterds and their wonderful creation, DAMN them all, they are sorely missed- was one of the happiest ones of my teenage days that didn't involve girls in tight clothes and short skirts.

About Virtua Cop, I think I'm the guy who imported the concept of 'akimbo' to Spain, I swear it. People looked at me like they would a martian every time I started a game. 'Virtua Spaghetto', my friends and I used to call it. Amazing, amazing times.

Virtua Cop playing with both guns is a lot more fun than playing with just one. Sometimes i'm glad I still have a PS2 and old TV...