Introduction: Kids Light Matrix
This is a weekend project for the family. Primarily aimed for kids around the age of two who love to switch on and off lights.
Step 1: What You Will Need
All consumables except for box were purchased from Aliexpress.com it can take upto a month sometimes six weeks for the parts to arrive.
16mm LED Lights (Indicator/signal lamp AD16-16AD)
200x Diodes depending on patterns you want (1N4148)
12x momentary on off switches (R16-504A)
50x push in connector. Size depending on your wire size
Wire, lots of it
Shrink wrap for wire- dont use tape it will take to long
12v power supply 500mA
Step 2: Make Your Box
The box is simply made from four pieces of 95x20mm and two pieces of ply to cover the front and back. The box is 500x500m, but this can be any size you want. The lights are spaced about 25mm apart in a grid pattern. To get the best spacing find the middle of your box and then start marking out the locations of the holes. The three holes for the switches are centred above the lights and placed 50mm from the lights center (double spacing)
Drill the holes with the 16mm hole saw. attach the front and back panels. We used panel pins for the front side and 5 small screws along each of the lenghts of the back panel. And make sure that at least one light fits. If it fits then paint the box in any colour.
If any paint gets in the holes just redrill them. Remove the back panel and put it somewhere safe
Try and use a gloss paint that can be wiped and cleaned.
Paint a few coats to make sure the surface will be durable after all this is a kids toy.
A roller will give a smoother surface than a brush.
Step 3: Install the Lights
The lights will need to be dissembled before they are installed. When the locking screw and rubber seal are removed screw the lights in to the from the front. We wanted a smiley face so we started there. Check the excel sheet for our pattern but otherwise just install them randomly as you feel fit. Label each row and column on the back side of the front panel and then the colour of each light. This will help you when wiring it all up.
Try and keep the lights wire mounting screws facing the same way we used an up down orientation.
Step 4: Wiring It All Up.
We used different types of connectors in this project as that is what we had at home. Use the type in the photo it will save you lots of time and frustration.
1. Firstly connect all the tops of the lights terminals to the power supply.
2. Connect the pigtails to each of the bottom terminals
3. Connect the terminal blocks to the pigtails
4. Connect each pattern one at a time, don't try and connect everything all at once. It gets very confusing very quickly. If you have different colour wires use alternating colours when wire up each pattern it really helps. We found that having the excel sheet visible while connecting to the lights was really helpful Check the excel sheet to see what lights we connected.
Try and cut each wire so that you can route the wires around the outside of the box. In our case three patterns are routed through the centre of the board
Once the first pattern is connected to all the terminal you will need to solder a Diode to each wire. This is because there are lights connected to each other and multiple switches allowing multiple grounds. Using the diode allows the current to only flow in one direction. Make sure you get the polarity of the diode correct.
Cover the end of the wire and diode with shrink wrap and heat the plastic
When all the diodes are connected and shrink wrap tight, twist the ends of the diodes together. and push them bundle though the hole you plan to put its switch.
Ground the bundle of wire and make make sure all the light you expect to work actually work. If there are any problems you will most likely see them after the second pattern.
Step 5: Keeping It Tidy
After each patten is complete try and cable tie the bundles together and add each new pattern over the last one. We found this made it much easier to work with.
Connect the ends of each pattern to a terminal block and secure the terminal block using hot glue or screws on the other side of the terminal block run a short wire that will reach from the terminal block to the switch.
One of the patterns contain all the RED GREEN and BLUE lights to save on wires and time you can connect all these colours to a fourth terminal block (dont forget the diodes) and then run this terminal to its own switch.
Step 6: Installing the Switches and Power Supply
The switches are installed the same way as the lights. And again the screws were installed in an up down orientation. All the top terminals on the switches were connected to ground and the bottom to each pattern. connect the short wire from the end of the terminal to the switch.
Check that each pattern works as you go.
Install the power supply in the box (i used hotglue to keep the PCB in place) and Drill a hole in the side of the box for the mains supply.
Step 7: Finishing It Up
There are three extra switches for future use, perhaps an arduino pro mini ruining though a few patterns.
Screw the back panel on secure it to a wall.
Plug it in a enjoy
Thanks to my wife for doing all the leg work. Love you Uli