I wanted to share the mods I made to my Zizzle POTC machine. I want to thank Mocean on this forum for the brilliant idea of using an Arduino micro controller to power the coils in the machine. Part of the reason I did this mod was to protect the PCB from any high-voltage responsibilities. I have another Zizzle that has what appears to be a fried voltage regulator/PWM IC and I have a feeling that somehow something in the 24V circuit got shorted to the lower voltage logic portion (5V?) of the PCB and toasted everything. I also noticed that the playfield LED’s and LCD backlight flicker and dim when coils are fired, and I assume that the constant voltage fluctuations are not good for the PCB in the long run. As I don’t want to risk frying another very hard to replace PCB, I want to do everything I can to protect it.
With that in mind, my goal was to completely isolate and remove the 24V circuit from the PCB and have it powered by its own, separate and isolated 24V power supply. The plan was to use the Arduino to control the four coils completely independent of the machines PCB or main power supply. I decided to use the Arduino ‘Leonardo’ board since it had more interrupts (five total) then the standard ‘Uno’ board, and I figured this would make coding a lot easier. After a lot of soldering and coding I have everything working perfectly. Aside from what I mentioned above I made several other mods to the machine as well and will list them, along with photos, below:
- Added illuminated power switch on front of cabinet. Switch in rear has been removed.
- Added a 6-outlet surge protector inside of machine for GI, USB, 9V, and 24V power supplies.
- Added authentic arcade buttons for flippers and disabled the faulty stock buttons.
- Added a 5V and 9V GI circuit. The 5V circuit powers #44-style pinball LED’s and bayonet bulb sockets were added to playfield in selected areas. The 9V circuit powers the LED strip and bar lighting on the playfield. It also powers the two flasher lights added to the playfield (described below and in photos).
- Added two flashers to playfield that pulse when pop bumpers and slingshots fire. Also fires periodically during attract mode (thanks to Arduino). The flasher bulbs are actually #44 6.3V incandescent bulbs over-powered to 9V so they are very bright. They are only on for fractions of a second so they should last a very long time. These are controlled by microswitches that are mounted and mechanically triggered by the pop/sling coils (or Arduino relays in attract mode).
- Added LED strobe light over the Cannibal Island target (see photo) that strobes red/green/blue for 10 seconds when target is hit. This too is controlled by a microswitch attached to the target under the playfield and is powered by one of the three 5V 1-amp USB chargers inside of the machine.
- Arduino code simulates end-of-stroke switch on flipper coils… Flippers triggers at full force (24V) for 200ms then voltage drops 60% (using PWM) while flipper is being held. This avoids the coil from burning out if the player holds the flipper button in for a long period of time. From what I read coil damage happens a lot on these pins.
- Pop and sling coils pulse and are not held “ON” when their switch is activated, thereby removing the risk of a coil getting stuck on if a switch gets jammed.
- Arduino monitors for idle activity. If a game has been started and 3 minutes pass with no activity, the code triggers a relay that activates the end-of-ball switch several times to put the game back into game-over mode.
- When the machine is in game-over mode, all coils and flipper buttons are disabled. The start button on the front of the machine is now only connected to the Arduino, and when it is pressed the Arduino triggers a relay to activate the start-switch circuit to the PCB. This way the Arduino knows when to re-activate coils/buttons for game play.
- Furthermore, when in game-over mode, the Arduino, via relays, periodically on roughly 3-minute cycles, activates attract-mode events where flashers and LED strobe light flash in three different pattern sequences.
- Toys and props added to playfield to enhance esthetics. (see photos).
- Added center bumper post between flippers since ball drains so easily down the middle.
- Added bumper posts to side drains to shorten width of the drain since ball drains so easily.
- Used small 1/2” X ¼” self-adhesive velcro strip on playfield between rollover lanes to act as a ‘speed bump’ to increase the odds of the ball falling into one of the lanes. Anyone who has played these knows it is very, very difficult to get the ball to go through these lanes, as there is no skill shot possible to make it happen.
All of the materials for this project ran just under $50 and I purchased all of it on Ebay. I used three USB wall chargers (each cost $2) inside the machine to power the GI and Arduino. I mounted a second, standalone 24V power supply used solely for the coils. This plugs directly into the home-made circuit board I constructed to interface the Arduino to the rest of the machine. I mounted two strips of header pins on my homebrew board that line up exactly with the females on the Arduino, so it plugs directly into it (see photo). As you can see by the photos the four JST-style coil connectors now plug into my new homebrew circuit board and no longer into the main PCB. In fact, the flipper/pop/sling switches are no longer connected to the main PCB either, so a 24V request is never even sent to the PCB. The flippers/pop/slings and their respective switches work even with the main PCB completely unpowered and disconnected from the machine.
Hope you like my mod. If you have any questions or would like to see the code, pinouts, wiring specifics, etc, just let me know.
Lastly, I was able to find and order 2, 5, 6, and 7 – pin JST connectors through Ebay. These, along with a standard IDE ribbon for the LCD display are all of the connectors the main PCB uses. With these connectors it’d be pretty easy to whip up a small homebrew interface board for literally all of the wiring harnesses these machines use. Since coding libraries exist that allow multiple Arduino boards to communicate serially, it’d be theoretically possible to use one board to control coils (as I did in the above project), one to control an LED matrix for all of the playfield lights, one to handle a switch matrix and logic, and one to control the LCD display (with the help of pre-written libraries) and a sound board. This would work nicely since the ‘Uno’ boards have 20 I/O’s each and the Zizzle’s have less than 20 switches and playfield lights. In theory this would allow for programming of a completely new rule set if desired, a dip switch for multiple selectable gameplay rules, and an open source way to have a rom, along with cheap, readily available, non-proprietary hardware to restore and maintain non-working machines as they age and the non-repairable, proprietary PCB electronics eventually and inevitably fail. In all likelihood I doubt I’ll have time to take it this far, but it is food for thought, and I’ll share any further progress I make while messing around with it.