Table Tennis Scoreboard

Too lazy to keep track of your Table Tennis / Ping Pong score?
Or maybe your just sick of always forgetting it?

If so, you may be interested in building this digital Table Tennis Scoreboard.

Here are the highlights:

• Tracks points, games, server, and playing side.
• Mounts to a wall, cubby, tabletop, or tripod.
• Pre-programmed to play official table tennis rules.
• Record each point with the press of a button.
• Wireless buttons last 5+ years on a coin cell battery.
• Ultra power-efficient display.
• Easily visible with large 5" bi-color 7-segment numbers.
• Display itself can also be battery powered.
• Many pre-programmed adjustable parameters.
• Arduino based chips and programming language.

For more fancy product-shots, please visit my website:
https://rapidwhale.com/scoreboard.php

Thanks, and enjoy.
-Josh!

You can build your own referencing these open source files.
or you can buy a complete DIY Kit from my website.

Here is everything you will need:

Laser Cut Parts:
- Included in kit.
- or cut them yourself with the open source files.

Printed Circuit Boards:
- Included in kit.
- or wire your own on prototyping board referencing the open source wiring schematics.

Electronic Components:
- Included in kit.
- or purchase your own referencing the open source bill of materials.

Safety Glasses
- To protect your eyes from the nasty things like acrylic glue and sharp electronic component leads that will go flying when you cut them.

Wood Glue
- To glue the housings, which are mostly wood. You could probably use any CA / Super Glue as well, but for this project I preferred to use Tacky Glue or Elmer's Wood Glue.

Acrylic Glue
- I like the Acrylic Cement from TAP Plastics. You can use CA / Super Glue as well, but that is likely to fog-up the acrylic (which might not matter if you careful in your application and cleanup).

Clips / Weights
- Binder clips and weights are great for holding pieces as the glue cures.

Soldering Iron / Solder
- To solder many electronic components to PCB's / prototyping board. Best to use a small "pencil" soldering iron. I'm a big fan of Kester 44 Rosin Core 63 / 37 0.031" Solder (pictured). Be sure to solder in a well ventilated area and ideally with a fume-extractor.

Wire / Wire Strippers
- To make connections between PCB's or on prototyping board. I used 20-22 AWG wire.

Paint Marker (or just paint)
- To apply in areas where we don't want light to shine through the acrylic.

Basic Tools
- A phillips screwdriver, flush diagonal cutters, needle nose pliers, and a small amount of sand paper should do it.

Reference the exploded view then:

- Begin gluing the acrylic.
- Insert the hardware (QTY: 2 of M2.5 hex nuts per button).
- Finish gluing the acrylic (Use the PCB / prototype board as a jig to ensure proper acrylic part locations before gluing).

Reference the exploded view then:

- Begin gluing the wood (Part orientation is critical).
- Flex the wood with extreme care (It is quite fragile as this point).
- Spread the glue liberally along the inside to increase part strength.
- Run glue along the corners, pushing it into the laser kerf cuts to greatly increase part strength.
- Use the Acrylic part of the button as a jig to ensure the wood glue dries such that the button housing will fit the acrylic piece.
- After the glue is dry, sand lightly to along the outside to remove excessive glue-spots.

Reference the exploded view then:

- Remove the protective backing from the surfaces to be glued.
- Begin clamping and gluing the acrylic.
- Insert the hardware (QTY: 12 of M2.5 hex nuts and QTY: 4 of M4 low-profile hex nuts).
- Finish clamping and gluing the acrylic.
- Paint the white surfaces as shown to ensure light does not pass through the acrylic (it is important that your paint is as opaque as possible to ensure it blocks the powerful light of the LEDs that will be resting just behind this surface).

Reference the exploded view then:

- Lay out the pieces in a logical manor.
- Cut out the circle(s) depending on how you plan on mounting the display (Think about how you want the power cord to enter the display and cut out the hole accordingly, and cut the center-most hole as well if you plan on mounting it to a tripod).
- Begin gluing the wood.
- Flex the wood with extreme care (It is quite fragile as this point).
- Spread the glue liberally along the inside to increase part strength.
- Run glue along the corners, pushing it into the laser kerf cuts to greatly increase part strength.
- Use the Acrylic part of display as a jig to ensure the wood glue dries such that the display housing will fit the acrylic piece.
- After the glue is dry, sand lightly to along the outside to remove excessive glue-spots.

- Collect the required electronic components.
- Insert the small components according to the PCB silk-screen
- Solder the small components and trim the excess leads.
- Insert/solder/trim the other components (The dip-switch and tactile-button are inserted on the opposite side as shown. Not the orientation of the dip-swith).
- Insert the pre-programmed micro-controller, radio, and battery (Polarity is critical).

Build both identical PCBs.

- Collect the required electronic components.
- Insert the BLUE LEDs (As shown) taking note that the PCB silk-screen indicates the LED positive (+) lead-locations, and also indicates the different color LED locations (solid-bar = BLUE, no-bar = GREEN).
- Solder the BLUE LEDs and trim the excess leads.
- Insert/solder/trim the GREEN LEDs.
- Insert the resistors and 16-pin housings (on the back side of the PCB, opposite of the LED's). There is a notch in the 16-pin housings, position it according to the silkscreen on the front of the PCB.
- Trim the resistor and 16-pin housings completely flush on the front of the PCB

Build all 4 identical PCBs.

Build both identical PCBs in a similar fashion.

Build this PCB in a similar fashion.

- Take note of the important text in the attached photos.

Time to bust out that 20-22 AWG wire. If you have 5-wire ribbon cable (not pictured), that would make this step a little easier.

- Position your Brain PCB, Rocker-Switch, and Barrel-Jack accordingly so that you know what length to cut your wire (Cut the wire with a few extra inches for ease of assembly).
- Solder the + / - leads to the barrel jack (+ lead is the one connected to the center pin as shown).
- Attach the crimp connectors as shown and solder onto the Vin of the Brain PCB (Don't push the connectors completely onto the rocker-switch until we are doing final assembly).
- Cut your wire to length and solder it on as shown to connect all of the PCBs.
- Trim the solder-joints flush with the PCB's facing the display (otherwise they will not rest flush against the back of the display).

Your end result should look just as neat as pictured.

- Wash any residual laser-smoke from each piece (Block the drain or do not work in a sink to ensure no parts are lost).
- Lay them all out to dry.

- Collect the required components and assemble the buttons as shown.

- Collect the required components (Hopefully all of your display acrylics are dry by now).
- Remove the protective backing from both sides of the acrylic backing-plate.
- Drop in all of the frosted display acrylics.
- Cover the frosted display acrylics with the backing plate.

- Lay out the required components as shown.
- Fit the PCB's to the display acrylic piece and secure them with the M2.5 x 6 machine screws and washers (do not over-tighten).
- Attach the rocker switch as shown.
- Secure the Brain PCB to the housing with the same M2.5 x 6 machine screws and hex nuts. You may need to remove a button-cover or two to fit the PCB, then push the button covers on from outside of the housing.
- Secure the barrel-jack through whichever hole you chose to knock-out (The washer and nut go on from outside of the housing)
- Sand the lip of the housing to ensure a smooth, easy installation of the display acrylic.
- Fit the display acrylic (If it isn't going on without much force, check clearance and sand accordingly).
- Secure the display acrylic with the QTY:4 of M4 x 45 machine screws.

- Set the Button and Display dip-switches accordingly. The #1 digit on the dip-switches for the wireless buttons tells the display which wireless button it is communicating with it. The #2 through #4 digits on the dip-switches is for setting a channel (There are 8 possible channels, which means up to 8 Table Tennis Scoreboards can work independently in a single room).
- Peel off the protective backing on the display acrylic

*** Moment of Truth ***

- Plug in the wall-wort and power up the display (It should look as shown).
- Cycle through the different settings, and test the wireless buttons are working. If you notice any dead or flickering segments on the display, it is likely a result of mishandling the accompanying LED. If so, it will need to be replaced.

I suggest mounting the wireless buttons with industrial strength hook-and-loop (Velcro). I'd suggest mounting them under the table, directly in the center if possible.

Be sure to check out the other pictures and the DIY Kit on my website: https://rapidwhale.com/scoreboard.php

Thanks.
-Josh!