Many months have passed, but I found some time to work on the Arduino project again. The objective of the next step is to do a proof of concept on the HUD (head-up display) of the slotmachine. While I have no idea if HUD is the “official” way to refer to the top half of the slotmachine, where the feature-game is played, it seems like a sensible name.

Anyways; the (dutch) website gokkastenarchief.nl is by far the best reference I could find. The image below shows the ‘HUD’ and what’s on there.

Clean image of the original ‘HUD’ found on GokkastenArchief.nl Lower part of the machine with the reels, all possible prices, gambling feature on the right There is virtually no information online except for this very usable images from GokkastenArchief.nl

The feature-game is triggered by points that are provided by the 4th reel and played with cards that are displayed on this 4th reel too. For now, let’s forget about that and just proof the concept of driving all this lights (and some simple sound effects) from the Arduino.

A simple sketch (created with the great online platform circuits.io by AutoDesk) of the setup used:

Playing around with circuits.io to describe the setup for this test LED strip used for writing witing some display software

The interesting part is the thing on the bottom-right, called a NeoPixel strip by AdaFruit. I got a leftover piece with 46 NeoPixels that I used to simulate the 3 main parts of the HUD.

  1. Display of Points (left) that trigger the feature game (their function is not important for now)
    • Steps 1 through 10
    • Mystery Number alongside position 4
    • Gelijk is Goed alongside position 5
    • Andere Kaart alongside position 6
    • Joker along position 7 and 10
    • Kaartspel along position 8,9 and 10
  2. Deck of Cards (called Kaartspel in dutch) that will start when 8, 9 or 10 points are reached
    • Cards 3 through 10, Jack, Queen, King and Ace
    • Gamble feature Hoger (higher) and Lager (lower)
  3. Prices to win when gambling with the Deck of Cards succeeds
    • 2, 4, 10, 20, 40, 60, 100, 200
    • Special prices Mystery Prijs, Nudges, Kies je Prijs and Super Match

On the left are all the lights that make up the feature game In the center of the display are all lights for the Deck of Cards and in the left-upper corner the gamble (higher/lower) feature The ladder of prices to win when gambling with the Deck of Cards succeeds Simulation of all the lights that needs to eventually be there to play with the tribute slotmachine

When we count all that up; there are 44 LED’s to drive in this proof-of-concept for the HUD. The strip was kept intact and was laid alongside a printout with the symbol.

I thought it was nice to have some simple sound effects to go along with the moving lights, but did not want to use mp3 or such files. Luckily, after some googling I came across this nice library of sound effects that sends simple straightforward signals to a piezo. Little memory footprint and exactly the sort of sound effects I was looking for.