48 replies to this topic

[Tesla]

That real "Popping-a-Game" sound ... is there really a good way to do it with just SSF-7.1 . Seems limiting to me, so I'm thinking no. But if you know a way, please mention it.

 

So, I found real-hardware "Replay Knockers" here:

http://mjrnet.org/pi...hp?sid=knockers

 

Doesn't look too expensive or hard to install ... except for all the Prerequisites. 

It's in the DOF section, so I assume I would have to get that working first?

 

Do cabinet owners usually enable DOF for just one thing?

Looks like I need some kind of controller board to fire it?

 

Can I even enable DOF and get this working with a little Pinscaped KL25z (with soldered-in Headers) ? Or is this beyond my reach with current setup?

Edited by Tesla, 30 September 2025 - 02:14 AM.

[mjr]

Knockers are indeed a tough effect to replicate convincingly with speakers.

 

DOF is definitely what you need for that.  And yes, Pinscape on KL25Z works happily with DOF; you just have to configure some outputs ports in the Outputs section. 

 

But you can't connect a 50V/4A coil directly to a KL25Z GPIO, or even an LedWiz port.  High-power devices like that need a booster circuit.  The Build Guide chapter on KL25Z standalone outputs talks about that and has several examples:

 

http://mjrnet.org/pi...tputsStandalone

 

For a knocker, the "pre-built MOSFET board" is probably your best option.  Those are cheap and easy to wire.

 

If you want to do a proof-of-concept test just to make sure you can get the software setup working, you can connect a small LED to a KL25Z GPIO port, with 3.3V power and a resistor chosen for 5mA current.  The KL25Z GPIO ports can handle that much directly (and that's ALL they can handle directly - don't go above 5mA).  Configure everything on the DOF side as though that port is the knocker, and then you can test your setup by verifying that the LED lights up briefly when you trigger the knocker port in the VP DOF test table.  Once that works, it's just a matter of replacing the LED with the booster input that drives the coil.

 

Another benefit of getting a knocker going is that you'll have all of the basic plumbing in place to add any other feedback effects you decide aren't cutting it with speakers.  Shakers, fans, and lighting effects (flashers, beacons, strobes) are probably the top ones there.  It'll be very little incremental work to add each additional effect.

Edited by mjr, 30 September 2025 - 02:19 AM.

[Tesla]

That's all encouraging enough, thanks. So, I will do my homework (read your manual) and look into it further. It looks sorta like an electro-magnet?

 

I do have a curiosity to do things in yall's standard (simple, tested, and proven) VP way. 

 

However, in the back of my mind, I'm pretty sure there is a PixHawk Drone way. I also built a little pet-robot once ... back then I used these Relays that could handle some volts/amps, but were activated by TTL signals. However, you are talking about some major power there and those relays require an-OFF signal as well. 

[digitalarts]

Hi Tesla,
Imho No need to use a "original" knocker device.
I use this:
https://www.amazon.d...aps,121&sr=8-3#

Placed it in Backbox, added a small Metal Plate as "Touch place" so the Sound IS very "hard", AS it should 😉

(Sorry for the uncomfortable Link, it should only be use AS example)

Very cheap device, 12v. (Don't forget to add a Diode for protection, See MJR bible)

Edited by digitalarts, 30 September 2025 - 04:34 PM.

[Tesla]

Wow. I had no idea I could do so much with just my little standalone Pinscaped-KL25z. Seems like every-time I go to read more of your Build-Guide I find more good info. I think I'm skipping pages because they are confusing. However, as I learn more of the basics, these pages become understandable and the projects become viable.

 

I have no problem building either one of those simple Booster Circuits. My problem is sourcing all the correct parts and getting them here in front of me. Plus, I need the Coil/Solenoid and it's looking like a fairly high-powered power-supply.

 

I agree that a "pre-built MOSFET board" is a nice shortcut. Most look fairly well built. I'm hoping they have some protection built-in (maybe even when an on-board component fails). It would suck if my KL25z got blown-up. Also interesting that you never see Fuses (even Slo-Blow ones) on boards any more.

Anyway, do any of these on Amazon-Prime look good to you? Think Reliability, Durability, and Flexibility (over money cost). 

 

Hilitand 4-Channel MOSFET-Module

 

MOSFET-Module with Opto-Isolation

 

Seloky 1-Channel Dual-MOSFET High-Voltage Module

 

Some above are 4-channel. I'm not really interested on adding light/motors but if I was to add one other device later, I think it would be 2-solenoids for the 2 main flippers. Seems like a 4-channel could do that, or just run multiple single channels ones.

 

If it's this easy to add ... seems like their should be a Replay-Knocker-Kit for sale. Or maybe everyone buys the big-boards and I'm in the minority trying to sqeak-by with a baby-board (who knows <smile>). Anyway, what do you think of this kit. I would not mind helping to support these guys if you think it will work (and they can get it to me fairly quickly).

 

https://www.clevelan...-conversion-kit

 

That looks like everything I need. I'm guessing it runs from only 12v with a DC-to-DC Converter/Amp (interesting). Maybe weaker than any of yalls, but I'm thinking it might be enough sound (my cabinet is in a house, not an arcade). I think even a weak one will be loud here (and will still scare our Bengal-Cat).

 

Finally ... so once I get this working in DOF, I assume it's going to stop making the "Pop a Game" sound over the speakers? (I'm hoping so).

Edited by Tesla, 25 October 2025 - 02:36 AM.

[Tesla]

Hi Tesla,
Imho No need to use a "original" knocker device.
I use this:
https://www.amazon.d...aps,121&sr=8-3#

Placed it in Backbox, added a small Metal Plate as "Touch place" so the Sound IS very "hard", AS it should

(Sorry for the uncomfortable Link, it should only be use AS example)

Very cheap device, 12v. (Don't forget to add a Diode for protection, See MJR bible)

 

Here it is on the Amazon-USA website, even on Prime

 

Heschen 12v Solenoid

 

Looks like this might be perfect, so thanks for the recommendation.

 

Like I was just posting ... those real ones might be overkill for my uses ... but needs to be a real one ... and I need to be able to buy it easily.

 

What are you using for the Booster/Controller circuit?

 

This is gonna be so cool ...

Edited by Tesla, 25 October 2025 - 02:42 AM.

[digitalarts]

No Booster, Just a separate 12v PSU for some 12v Toys.
This solenoid for knocker, a "car-door-window-motor" for Gear, a Vibration motor (search for Type 775) for Shaker, some Siemens contactors for flipper/bumper/Droptarget
All dof Toys controlled by a "Rigmaster", it's a pinscape compatible kl25z Board.

[Tesla]

No Booster, Just a separate 12v PSU for some 12v Toys.
This solenoid for knocker, a "car-door-window-motor" for Gear, a Vibration motor (search for Type 775) for Shaker, some Siemens contactors for flipper/bumper/Droptarget
All dof Toys controlled by a "Rigmaster", it's a pinscape compatible kl25z Board.

 

Nice setup.

 

Yeah, while my ALP is mostly gutted, I kept the 12v Power-Supply installed. I figure it must be fairly powerful as it ran the whole ALP originally. I'm in the process of figuring out it's non-standard JST connectors and hopefully put it to use. It is outputting some 12v says my volt-meter.

 

I found the recommended 1N4007 Diodes on Amazon.

Edited by Tesla, 02 October 2025 - 01:44 AM.

[Tesla]

Here it is on the Amazon-USA website, even on Prime

 

Heschen 12v Solenoid

 

Looks like this might be perfect, so thanks for the recommendation.

 

 

 

From Amazon, I ordered:

- that (still pretty loud) 12v solenoid

- What looks like a good "pre-built MOSFET board"

- Some 1N4007 Diodes (in an assortment) 

- Some hookup-wire (also an assortment kit ... because I'm tired of scrounging for it)

- Some breadboards for my JST-XH connectors

- Terminal-Strip assortment (I think I need one for my KL25x signal grounds ... 3 little pins ain't cutting it)

 

No easy turn-key kits for me ... just following MJR's manual and going old-school hardware-hack route.

Taking advantage of Amazon's (still a little slowish) "Star-Trek Transporter" Technology (aka Prime)

Edited by Tesla, 25 October 2025 - 02:41 AM.

[mjr]

Tesla - sounds like a good plan. Let us know how it goes when the parts start coming in.

 

I agree that a turnkey kit with a few of the high-priority toys would be great if someone offered it.  The recently closed Zeb's Boards at one point had a comprehensive feedback kit, and I think PinOne might offer something like that as well now, but something smaller-scale that just complements an existing SSF setup could be a good seller - adding just a few big things that SSF isn't good at, like knocker, shaker, and flashers.

 

> Finally ... so once I get this working in DOF, I assume it's going to stop making the

> "Pop a Game" sound over the speakers? (I'm hoping so).

 

Yes, you can do that, although it does take a manual step (the sound effect won't just go away on its own).  Open the VP Keys/Nudge/DOF dialog, go over to the DOF Controller Options section, and change Knocker from "Both" to "DOF".

Edited by mjr, 01 October 2025 - 06:31 PM.

[Tesla]

Tesla - sounds like a good plan. Let us know how it goes when the parts start coming in.

 

 

 

All the parts are here and I was just getting ready to hook it all up for the first time. I liked this one because of the Opto-Coupler, versatile, and can handle some power.

 

MOSFET-Module with Opto-Isolation

 

The 1N4007 Diode for the 12v coil is no problem. But then I saw that your Build-Guide says I need a limiting resistor on the low-voltage control line. I've only connected switches to my KL25z so far (so those haven't been required).

 

I definitely don't want to blow-up my KL25z but do you really think I need it? It says "Efficient Current Control with Control current ranging from 1-5mA with varying voltages" . The PCB has a tiny-LED on it but that's about it.

Edited by Tesla, 25 October 2025 - 02:44 AM.

[mjr]

Definitely good to double-check these things!  I think you'll be okay hooking that device's control input directly to a KL25Z GPIO.  It would be nice if they gave you a schematic to be sure, but it looks like the control input is an opto through a 1K resistor, which should be perfectly safe.  If they didn't have the resistor on-board, that's when you might need to add one of your own, but it looks like it's already there.  If you want to be absolutely sure, connect the control input to a 3.3V power source through an ammeter, and confirm that it's reading around 2mA.  Anything up to about 5mA is safe.

[Tesla]

Definitely good to double-check these things!  I think you'll be okay hooking that device's control input directly to a KL25Z GPIO.  It would be nice if they gave you a schematic to be sure, but it looks like the control input is an opto through a 1K resistor, which should be perfectly safe.  If they didn't have the resistor on-board, that's when you might need to add one of your own, but it looks like it's already there.  If you want to be absolutely sure, connect the control input to a 3.3V power source through an ammeter, and confirm that it's reading around 2mA.  Anything up to about 5mA is safe.

 

Wow, glad you are around today (I'm sure you are busy).

 

I think the schematic is here:

 

 

Good to know KL25z GPIO Control-Current is actually good up to 5mA, and this device is specifically rated at 1-5mA .

 

That said, I looked in my parts box and found both a 1K-Ohm and a 680-Ohm resistors (little ones, 1/4-watt). 

 

Somehow, I've never tested for current with my meter (other than using the clamp) ... but I can watch a YouTube video if I need to.

 

But instead of that ... following your Guide ... with the Resistor inline ... if I use the Pinscape Tester and get the little LED on the device to light-up, then I am good? Or, do I need to have a small load on it to test it fully? I'm a little impatient sometimes, but I really DO LIKE doing things the proper way (doesn't necessarily have to be easy-way). <smile>

Edited by Tesla, 05 October 2025 - 11:27 PM.

[mjr]

The schematic in the video looks like what I’d expect, and it does show a 1K resistor already there, so I think you’re fine without an additional external resistor.  However, adding the external resistor won’t pose any danger, so it won’t do any harm to try it.  But I expect it might end up being too much resistance when added to the internal one that’s already there and might prevent the trigger circuit from tripping, so you’ll probably end up leaving it out in the final setup.  Really the best way to be sure if you want to test it for KL25Z safety is to try the 3.3V power test I mentioned, applying 3.3V power to the input trigger and see what kind of ammeter reading you get.

 

As for testing, the LED lighting up is a pretty good indication, but I think you should test with a load to make sure.  The LED is on the input side of the circuit, so it’ll tell you that current is flowing there, but it won’t say for sure that anything’s happening on the output side.  Anything you have handy to use as a load would work, like a small lamp or LED.

[Tesla]

One other thing...

 

I'm fairly clear on the GPIO Control-Line and what needs to happen there.

 

My current question is about your schematic in the Guide. It shows the Power-Supply red-POSITIVE already connected to the Feedback-Device. AFAICT, only the Negative line is switched by the Mosfet-Board in that example.

 

But this one (and some other's I've seen) seems to have 2-in and 2-out ... looks like to switch both the Positive and Negative (like a DPDT switch). So, I hook-up and switch them both, right?

 

Does the power to allow these boards to operate come from the KL25z or from the main Power-Source?

Edited by Tesla, 06 October 2025 - 05:12 AM.

[mjr]

> So, I hook-up and switch them both, right?

 

Yeah, if the board-specific instructions differ from the generic instructions, always use the board-specific instructions, since some boards don't follow the normal patterns.  It looks like these are high-side switches with P-FETs, which means they switch the "+" side, so you're exactly right that you'll have to wire the "+" side of the knocker through the board.

 

> Does the power to allow these boards to operate come from the KL25z or from the main Power-Source?

 

The trigger side power comes from the KL25Z, and the device side (knocker) power comes from the separate high-voltage source.  The two sides are isolated (by the opto) and won't interact electrically.

[Tesla]

Well, there really are no "board instructions" but that guy's video looks informative. I'll watch and try to comprehend more of it, but it looks like you connect BOTH the positive and negative of the power-supply to the INPUT side of the Mosfet-Device, and it "switches" them both. Likewise, you connect BOTH the positive and negative of the Feedback-Device (main load) to the OUTPUT side.

 

I built a little solder-able breadboard with a Red-LED (unknown specs), and a socket for the limiting-resistor. Using 3.3volts now, so I have a 220-Ohm Resistor in there now and that seems to work (both can be easily changed). On the other (separate) side, I was thinking I could do a similar thing for the GPIO signal and I can try different Resistors as well as take any Amp readings. 

 

I'm also curious to see how much current it's drawing and to find out just how much I can limit things and it still work. I'm kinda protective over my little KL25z <smile>. A 4-5mA limit is a bit scary as that is very little.

 

Also seems more appropriate to test a new/unknown device with the Pinscape stuff on low-voltage/low-current first. Not to mention getting DOF working for the first time. 

Edited by Tesla, 06 October 2025 - 04:01 AM.

[mjr]

> I'm also curious to see how much current it's drawing and to find out just

> how much I can limit things and it still work. I'm kinda protective over my

> little KL25z <smile>. A 4-5mA limit is a bit scary as that is very little.

 

Indeed, they are delicate.  It's definitely important not to try to drive too heavy a load with the GPIOs, but as long as we're on the subject, the thing you should be REALLY careful about is never exposing the GPIOs to a voltage above 3.3V  Virtually all of the stories I've heard from people who damaged a KL25Z went something like this: "I was working on my cab wtih the power on, and I dropped a screwdriver onto the 12V line..."  That's what always seems to do the damage - expose a GPIO to 12V or 24V and it'll fry the board instantly.  And it's surprisingly easy to do that if you have buttons wired to the KL25Z, because that means you have wiring all over the cabinet (the button wires) leading straight into KL25Z ports.  So keep those 12V and 24V and 48V lines nailed down and well insulated, so that nothing ever gets loose and crosses wires (literally) with a button input.

[Tesla]

 

The trigger side power comes from the KL25Z, and the device side (knocker) power comes from the separate high-voltage source.  

 

So, the SMD-LED is helpful, but cuts-into our (small) 5mA power-current budget for the select GPIO port.

 

So, once I get it working (hopefully with an inline resistor) ... where should I connect the two leads from the DMM to measure the current (in mA)?

 

I measure it when the trigger is activated (and therefore the load-device is running/activated/On), correct?

Edited by Tesla, 06 October 2025 - 07:37 PM.

[mjr]

To measure current, you put the meter in series with the load:

 

GPIO —— (+) Meter (-) —— MOSFET board trigger input

 

If you’re using an external resistor, it just goes in series as well, so it can go on either side of the ammeter.

 

> So, the SMD-LED is helpful, but cuts-into our (small) 5mA power-current budget for the select GPIO port.

 

It’s in series with everything too, so it doesn’t add any current load. When things are in series, the same current goes through all of them.