Props Any electrical circuit guys here? Ammo counter question for HALO rifle.


KragAxe

Member
I'd like to modify one of the nerf optical switched counters to work off a plunger/intermittent contact type stimulus. My question is: what kind of signal is coming in from these optical sensors? If I pull apart the cord is it just two wires that if tapped together will cause the counter to go down by one? I have a HALO gun project I want to use one of these on.

 

marinesniper

Active Member
im not sure my self but you have a good idea i would have to have one to tare apart to see what and how it is operating i might have to buy one of these on payday. if i find out i will let you know..
 

KragAxe

Member
Yeah, if they were half the cost, I'd buy one, rip it apart and see what happens. At $50, it's a bit steep just to rip apart. I didn't know if this was some imbedded binary code looking for multiple signals coming in from the sensor, or if it was just a two wire system coming in off the sensor that would imply it's just a "single pulse" causing the counter to go down one each pulse. I don't know enough about circuits to really understand how they work, though. I was hoping I could just attach a plunger type switch that makes contact each time the bolt slams forward, dropping the counter by one. I could easily fit that inside the frame. Of course, I'm assuming the counter itself can withstand heavy recoil!
 

KragAxe

Member
For those curious.....here's what I'm working on to go with my aluminum/steel Noble 6 armor. I'm shooting for end of October completion. We'll see. I still have a lot to do on both and two months is not much time at all! I really would love to have an actual functioning counter on it. DWAI on youtube did one, but he had a crapload of circuitry and wires stuffed in and used a dinky 22 mag commercial made frame and just added sections to it. This a complete scratch build.

 

Coreforge

Member
Hard to say how it's wired up exactly, but I doubt they're using usb, even though they're using usb connectors. It would be too much work and wouldn't make any sense to implement usb. Since the description says it doesn't work with grey or black darts, I'd assume it works by shining down some IR light and using a photo diode / photo transistor to look for a reflection. Either the end piece just has and LED and the photo diode / photo transistor, in which case you could just ignore the pins for the LED and either supply a voltage if it's a photo diode or just short the pins (with a resistor) if it's a photo transistor. If it has some circuitry in the end piece already, I'd guess it either pulls a pin high or low when a dart passes. So it might take a little bit of work, but it should be possible. Even if it uses some weird communication (which I doubt), the sensor still works the same and you could just hook up something directly to it and let the original circuit handle the rest. Also, have you tried asking the seller? I don't really see why they wouldn't tell you since it shouldn't be hard to find out by just taking one apart.
 

KragAxe

Member
I figured they were similar to a bullet chronograph, but instead of measuring the time between diode responses, it just measures a single response. I just don’t know enough about circuitry to know how to reproduce that signal with an alternate source.

The current Etsy item looks like a knock off of the original custom ones another guy used to sell on Etsy who was an electrical engineer and programmer. I’ll shoot them a message, but expect that they are just a reseller…..but it can’t hurt to ask.

I should have gone to class more in my computer science classes! :)
 
This thread is more than 4 months old.

Your message may be considered spam for the following reasons:

  1. Your new thread title is very short, and likely is unhelpful.
  2. Your reply is very short and likely does not add anything to the thread.
  3. Your reply is very long and likely does not add anything to the thread.
  4. It is very likely that it does not need any further discussion and thus bumping it serves no purpose.
  5. Your message is mostly quotes or spoilers.
  6. Your reply has occurred very quickly after a previous reply and likely does not add anything to the thread.
  7. This thread is locked.
Top