How i created a backlit RGB-LED Control Panel for my kids (Report / DIY Guide)
Final results first of cause :)
What follows is a list of my used components, as well as a few words where i took my inspiration. Finally the detailed report with a few suggestions for potential recreations. But make sure to read through, since i made some glorious errors :)
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LED RGB Stipes 5050 5M IP20 (4,26 Euro per 5 meters)
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LED Switch 3x (1,27 Euro each)
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LED Rocker Switch 1x (1,31 Euro each)
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PWM Controler 3x (1 Euro each)
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Cables(0,47 Euro per meter)
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Power Supply (8,99 Euro each)
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Thread inserts 20x (2,86 Euro for 20 pieces)
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Green LED for backlighting (0.34 Euro each)
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Wood of your choice and disposal (4 Euro)
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Total material costs approx: 35 Euro
The most expensive piece was the custom panel i made with Ponoko but this was mainly because of the high shipping costs to Germany. I've used the Black on White material. Depending on your design and shipment location you might be able to create this panel much cheaper.
Panel costs:
- Making $30.03
- Materials $12.00
- Shiping $34.77
Total costs approx: 96 Euro ($120)
Since i saw the Spaceship Panel Cody2084 created i wanted to make something similar for my kids. I loved the idea of creating something - anything - which was backlit and had buttons on it :). So when i needed a bit more light in the room of my kids this was the perfect excuse to create a RGB-LED Control Panel! It has to be backlit of cause (how could you see it otherwise? Its dark in the room, remeber?). And of cause it needed to have big colorful buttons. How else would the kids be able to use it? And its not like you could simply buy these control modules, right? So in this dire situation i was practically without any other option: i had to build it on my own!
Before i dive into my report, i want to thank Cody2084 again for his great report on his Spaceship Panel, i hope he doesn't mind that i took quite some inspirations from it.
Ok before you start make sure that you choose the right buttons, switches and controls for your panel. The diversity is huge.
I wanted the following features/requirements fullfilled by my control panel
- LED color and brightness should be fully adjustable
- There should be a fast way to get the LED to full brightness and white color. But this feature should not wipe the settings of the custom adjusted color and brightness.
- The module shoult have an on/off switch
- All controls should have a connector, so that the panel would be easy to remove
- Of cause the module should be backlit
- I didn't want to solder the ICs on my own while i was fine with soldering a few wire lines and connectors
I'm sure there are better solutions out there but i found these PWM modules to control the RGB LEDs. Its actual purpose is to control motors. But i found out that it worked just fine as a RGB controler. So thats how it would be able to adjust each color individually.
Now to be able to "overwrite" this settings i decided to use three switches (red, green, blue) to get each LED in full brightness mode with a simple press.
By combining these buttons one could create a total of 7 colors (red, green, blue, cyan, magenta, yellow, white).
This is the board schematic i came up with. Feel free to use and optimize it. Please bear in mind that at that point i didn't think about writing a report about my project. Thats why its looking very crude.
Here is the board layout. Red lines are cables, blue lines are soldered wires on the board. (I leave this here for completeness but do your self a favour and create your own, better schematic and layout!).
Beeing sure on what components to use i started designing the panel. As mentioned before I've used the Black on White material from Ponoko. I wasn't sure if the white is translucent enough for the backlighting but since there was no other fitting material available i took the risk. Ponoko has some easy to understand tutorials and templates. So it was easy enough to create my design. I've uploaded it here, feel free to use it as a template.
In retrospective i would probably increase the drilling holes for the PWMs and switches to allow for a little more tolerance. Otherwise it turned out to be just perfect! Make sure to leave a big enough border, since there will be the wood frame and no backlight can reach this region. Also add a cutting line on the perimeter for a clean material cut and also include the mounting holes. By the way i used the free software Inkscape and it worked like a charm.
As mentioned above i wanted the switches to have a connector, so the panel would be easily demountable. So its soldering time!
Make sure you mark every signal with a specific color. And don't let your concentration slip in the process. As you might be able to tell, i got the coloring wrong on one switch and had to mark these otherwise.
The cable for the PWM needs to be open ended. Make sure to coat the ends slightly with a bit of solder.
I decided to solder the cable for the LED-Strap directly to the strap. Make sure that the cable is long enough. Do not worry if its to long, you can put the rest of it into the box later.
At last i prepared the LEDs for the backlight.
Lessons learned
Although i was pretty happy with the cable assembly at this time, it was not very well thought out in retrospective. In a rebuild i would certainly change the following:
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Make the cables much longer! I can't stress this enough: at least trippling the cables lenght would have saved me a lot of hassle. It seems counter intuitive at first but you can achive a much more cleard and sorted cable harness in the box if the cables are long enough. With such short cables the box seems much more crowded and its cumbersome to lift the panel and detach the connectors. Also its bad for the backlight if the cables are not sorted properly.
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If you think you are smart by soldering connectors to your switches make at least sure that every switch gets its own connector. If not, well we will see that later.
Since i forgot to add the power supply for the LEDs in the switches to the schematic i've added a 10 Pin Socket with 12V/GND outputs to the board afterwards.
I've also added a 12 Pin Socket (in series connected) to hook up 4 LEDs for the backlight. The suggested supply voltage for the LEDs is 3.4V. Using my 12-Pin Socket and powering it with the 12V supply i get an effective supply voltage of 3V at every LED, which works just fine. This way i didn't need to convert the supply voltage or to use series resistors.
After thats done. Throw some voltages and ampers at it and look if it is working!
Hooray it does! I played several minutes with it, but lets get back to work.
So now lets simply insert all the switches to the panel and thats it. Hey why do we need a chapter for this simple task anyway?
Ok here is the task: grab the below 3 switches (which are conveniently connected to 2 intertwined connectors) and click these into the 3 holes of the panel.
Sure, you would have known better than me, thats not going to work :(
So unwrap the heat shrink and disassemble the pins:
Now thread it through the holes of the panel and assemble it again.
Hooray its still working:
Feel free to skip this chapter entirely by beeing smarter than me in the first place :)
First measure out your frame. In my case the area of the panel was 18x18cm, so i decided to make each piece of the frame 18.5x8cm. I though making the frame slightly bigger then the panel wouldn look as crude as making it smaller and it allows for some tolerances. Make sure to cut it on the right side of the line, because your blade will make the length of the pieces smaller otherwise. When measuring i add the width of the blade to the next length of the piece to compensate for that effect.
Now mark the edges of each piece. I decided to give them all a simple 45° cut and it turned out pretty good.
After the frame is done, measure out the buttom, saw it, and put everything together. If something does not fit right, you may now correct it.
In my case everything was to my satisfaction and i continue with marking all drills for the threads and cable exits.
The downside of the PWM boards is that the knob is directly soldered to the board, this way i needed the board to be on the very edge of the frame.
At that point i realized i didn't had a fitting drill for my router. So i decided to use an even more advanced tool: the battery-powered screwdriver!
Screwing in the threads is not so easy. I also drilled 2 holes in the backpanel to make it easiert to mount it to the wall.
Now glue the frame togher. After that glue the frame to the buttom.
In the meantime i applied a natural oil/wax mixture for protection and better look.
After thats done i assembled the PWMs to the frame:
As it turns out the knobs don't stand out enough of the panel. My quick work-around was to glue a little piece of wood under the spacers. This did the trick.
To optimize the backlight i coated the inside of the box with aluminum foil.
To get an impression of the effect i made two test photos:
It may does not immediately stand out but by looking at the illumination of the flashlight, especially the silver body of it one can clearly see much improvement.
After the box was nearly finished i applied the panel to the box, marked the holes for the mouting and put it the threads.
Since everything worked out, i finally glued it the power supply socket and mounted the 4 backlight LEDs to the frame:
Finally done! I'm very pleased how it turned out. The backlight effect is better than i hoped for. As always there are quite a few things i would have done different in retrospective, above all allowing for much longer cables to be able to mount the cables to the frame. This wasn't possible this time and effects the handling and backlight. But all in all it was a very fun project and i am very happy how it turned out.
Mounting it to the wall and let the kids play. Ofcause I need to regularly test it to insure its still working properly :)
