LED光立方制作全过程（十二）
0赞Step 21Build the cube: solder a layer
Each layer is made up of 8 columns of LEDs held together by the legs of each LED. At the top of each layer each LED is rotated 90 degrees clockwise, so that the leg connects with the top LED of the next column. On the column to the right this leg will stick out of the side of the layer. We leave this in place and use it to connect ground when testing all the LEDs in a later step.
1) Prepare 64 LEDs
Bend the cathode leg of each LED 90 degrees. Make sure the legs are bent in the same direction on all the LEDs. Looking at the LED sitting in a hole in the template with the notch to the right, we bent the leg upwards.
2) Start with the row at the top
Start by placing the top right LED in the template. Then place the one to the left, positioning it so that it's cathode leg is touching the cathode leg of the previous LED. Rinse and repeat until you reach the left LED. Solder all the joints.
3) Solder all 8 columns
If you are right handed, we recommend you start with the column to the left. That way your hand can rest on the wooden template when you solder. You will need a steady hand when soldering freehand like this. Start by placing the LED second from the top, aligning it so it's leg touches the solder joint from the previous step. Then place the LED below that so that the cathode leg touches the LED above. Repeat until you reach the bottom. Solder all the joints.
4) Add braces
You now have a layer that looks like a comb. At this point the whole thing is very flimsy, and you will need to add some support. We used one bracing near the bottom and one near the middle. Take a straight peace of wire, roughly align it where you want it and solder one end to the layer. Fine tune the alignment and solder the other end in place. Now, make solder joints to the remaining 6 columns. Do this for both braces.
5) Test all the LEDs
This is covered in the next step. Just mentioning here so you don't remove the layer just yet.
6) Remove the layer
The first layer of your LED cube is all done, now all you have to do is remove it from the template. Depending on the size of your holes, some LEDs might have more resistance when you try to pull it out. Simply grabbing both ends of the layer and pulling would probably break the whole thing if a couple of the LEDs are stuck.
Start by lifting every single LED a couple of millimeters. Just enough to feel that there isn't any resistance. When all the LEDs are freed from their holes, try lifting it carefully. If it is still stuck, stop and pull the stuck LEDs out.
Repeat 8 times!
Note on images:
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Step 22Build the cube: test the layer
Connect ground to the tab you left sticking out at the upper right corner. Connect a wire to 5V through a resistor. Use any resistor that lights the LED up and doesn't exceed its max mA rating at 5V. 470 Ohm would probably work just fine.
Take the wire and tap it against all 64 anode legs that are sticking up from your template. If a LED doesn't flash when you tap it, that means that something is wrong.
1) Your soldering isn't conducting current.
2) The LED was overheated and is broken.
3) You didn't make a proper connection between the test wire and the led. (try again).
If everything checks out, pull the layer from the cube and start soldering the next one.
