The Mini Wall: the Electronic Game

Idea: Colyne, our 5 year old daughter, is a fan of the TV game show "The Wall" on NBC (TF1 in France), so for her birthday I decided to build a miniature table version.

Made of wood, the game consists of a tray with 200 nails where the balls pass. A LED matrix display shows the different steps and points. The system is controlled by an Arduino Nano and powered by a USB (5V).

In this Instructable, you will find the plans, Arduino code, schema, background image ...

Video:

Operation:

• at the start, we choise the number of players (1 to 9),
• the game takes place in 7 rounds,
• In each round, players receive between 1 and 3 balls (automatic distribution) and the LEDs light up in green or red,
• the player places the ball (s) in the desired position (1 to 7 at the top) and activates the start (by lowering the blue lever on the right or left side)
• the balls fall and the score is counted (in + if green and - if red) and displayed on the screen - At the end of the 7 rounds, the winner is displayed along with all scores

Time spent: 50H (+ almost as much for study and programming)

Cost: about 60 €

Tools used: Circular saw, mini saw, drill, screwdriver, ripper, glue gun, hand tools ...

Balls diameter 16mm

Sorry for the rough translation

I created the background with Word and printed on two A3 pages.

The game board is made of 10mm MDF. An opening is made, at the bottom, for the recovery of the balls.

I did several tests to stick the paper, and the only one that did not curl the sheet was the double-sided tape. I cover it with a transparent vinyl to protect it.

I create a template by letting the blade 1mm beyond the table to make notches and I use it to position the nails. They are all aligned, straight and at the same height !

For the start and final guides, I used 2.5mm² rigid electrical cable, shaped on a jig. The board is drilled and the guides are glued.

The ball launcher consists of a board with 7 nails whose head is cut. The system is mobile with 2 hinges. The nails hold the balls up, and liberates them while returning under the board. A limit switch detects the launch.

The stitch counting system consists of 15 limit switches.

I'm using the steel rod coming from a hanger to connect them together.

I create an adjustable wooden support and I solding the common contacts on a rigid copper wire in order to "freeze" them.

I cut the side in 6mm MDF.

I bleed half, it will be used to embed the glass.

I connect the 2 sides with cleats. The wood receives a black bomb after a coat of primer.

The central wheel is cut with a hole saw. The groove is made at the table router.

At each half-turn, a ball is distributed. I have done several tests before (with an electromagnet for example) and it is with this system that I am sure to distribute only one ball at a time.

For training I get a computer CD player motor (drawer), which has the advantage of having a reducer (so turn slowly).

I add pins on the wheel and a limit switch to detect a half turn

For the ball gutter, I used a 40mm PVC pipe that I cut in 2 on the length by fixing it on a drop of MDF.

I cut 2 RGB LED strips and stick them on the sides.

A programmed Arduino Nano will drive everything!

I spent a lot of time developing the program!

You can download the Arduino code below

Main elements :

• Arduino Nano ATmega328P
• 2 x 74HC165
• RGB stip LED 5V
• LED matrix module MAX7219
• USB Type B female plug
• 16 limit switch
• 20 x 1 Kohms resistance

Steps :

• Step 0 : Init for new game
• Step 10 : Ask number of player
• Step 20 : Display the number of player
• Step 30 : Show current round of game
• Step 40 : Distributes the balls
• Step 50 : Choise color
• Step 60 : Ask player X to play
• Step 70 : Count points
• Step 80 : Find the winner
• Step 90 : Show all scores
• Step 100 : Reset all for start a new game

The LED display (MAX7219) and the control buttons are screwed on their support.

I use the other half of pipe to cover the top. The control panel is hidden by one of the plexi covered with tinted film.

For the exit toboggan (after the dispenser) I used 3mm multicel (a light PVC).

It is folded and glued to the glue gun and takes place after the dispenser.

The covers are installed (front and back) and the whole is painted black.

I used plastic plugs to maneuver the launcher.

The pleasure of seeing her daughter's eyes by opening her unique gift !!

Do not hesitate to ask me questions! Enjoy!