shot counter options

[wildething]

So i have a Pulse Rifle that i am slowly making more screen accurate have replaced the barrel so there is no longer a place for a light gate to count shots. was thinking of counting piston strokes was wondering if a pressure sensor would be the way to go or any suggestions appreciated.  

[Stuey]

I'm not familiar with the construction of the Pulse Rifle, but if your gearbox has the window at the back and there's room you could put a light gate there to detect the piston when it moves back with each shot. As for the rest of the electronics, a CD40110B decade counter should be what you need; it's a counter IC that can drive a 7-segment display directly. Daisy-chain two of them for 0-99 capability. You want to count down from 99 right? So have the reset button (either on the gun or automatically pressed by changing mags) trigger the reset input on the counter (which will set it to 0) and then immediately clock it down by 1 (which will roll it over to 99).

[Mike 8-{>]

I think a pressure transducer / sensor would be tricky to fit. It would mean tapping an air feed in to the cylinder which would be difficult and would be very difficult to get a reliable seal. The Pulse rifle kits use a Thompson I believe. Not sure on what level your electronics skills are like. Possible ideas could be trying to get a miniature or sub miniature micro switch in somewhere. Trying to fit a light gate in near the nozzle. Perhaps fit a reflective ir sensor and use a patch of reflective tape stuck to the air nozzle where t wont foul the hop rubber. Another possible solution is fitting a tiny neodymium magnet somewhere and using a hall effect sensor to detect the magnet. Possibly on the tappet plate or the piston body. However this will again be a tricky thing to sort out. There isnt much space within the Thompson body to fit any sensors. Not sure how much more room you get with the pulse rifle body kit installed over the top of it.

[Im going space]

I say the magnet could work if you were to situate it in the piston, sensor at the rear of the GB?

Or simply run it off the trigger. You'd have to work out how to count only semi or auto though.

[Mike 8-{>]

If the piston cylinder is brass and you had a tiny short cylindrical neodymium magnet you could drill a hole through the piston wall the dia of the magnet and glue it in place in the wall of the piston. A quick google reveals 2mm dia 1mm thick magnets are available. I am sure other similar sizes must be around. The brass will have almost zero effect on the magnetic field from the magnet. You could read the magnet's position through the cylinder wall. A steel cylinder would present more of a problem.  Hall effect sensors can be tiny these days. They do them in the SOT23 package (https://www.google.co.uk/#safe=off&q=sot23+hall+effect+sensor) which is really small. I think the new electronic G&G gearbox uses this approach in several places to sense the positions of various things. 

[wildething]

magnet looks the way to go there is a hole in the back of the GB and the guild rod is hollow there is a fairly large space behind the gear box

[spidermax]

You could tap in to the battery and work out the volt drop under load and program a PIC processor so that it counts each volt drop as a shot or use an arduino to do the same. a light gate will give the best real shots count as battery volt or gear box movement does not account for misfire depends how much work you want to put in.

 

Im currently working on a PEQ shot counter to put in to production so feel free to message me for any other bits.