NeoPixel Tutorial Part 1 - 5mm Straw Hat Blade Assembly May 1, 2017 15:35:28 GMT -5 ARKM, Wildcard, and 9 more like this
Post by naigon on May 1, 2017 15:35:28 GMT -5
NeoPixel String Tutorial
Part 1 of 2 - How to assemble the 5mm straw hat blade
This tutorial will go over actually assembling the 5mm straw hat style blade. In the second part I'll go over diffusion which will be applicable for both 5mm and strip blades.
The LEDs used in this tutorial can be found on SparkFun here: www.sparkfun.com/products/12999.
Step 1 – Create the left and right group for the LEDs.
Because the DOUT -> DIN connection is in series not in parallel, you cannot just bend all four pins up and solder them together. Instead, the proper thing to do is to create two groups, a left group and right group. Then when building the string, you will start with one from the left, and attach it to one from the right soldering 3 connections (PWR to PWR, GND to GND, and DOUT to DIN) up the blade.
Create the left group
For the left group, lay the LED with the legs facing down, and the longest of the four pins being the third from the left. That longest is the GND pin.
Figure 1 - LED before any modifications are made. The longest pin is GND, which is the 3rd from the left. Keep the LED in this orientation when constructing the left and right groups.
Start with the LED in this configuration. The GND pin is the longest, PWR is just to it’s left. DIN is the left-most pin, the shorter of the two outside ones.
Now, bend the GND pin away from you, and bend it up so it is sticking straight up the LED. The PWR pin is the second pin from the left, and it will need to be bent up facing towards you. When complete, the LED will look like the one below.
Figure 2 - An LED created for the left group. Notice that the GND is facing backwards and up, and PWR is facing forwards and up.
Repeat this step for half of the remaining LEDs, and place them to the left of you in one group.
Create the right group
For the right group, you will put the LED in the same orientation as in figure 1. However, now you want to bend the GND pin facing up towards you, and the PWR pin facing away from you. Repeat this step for the remaining second half of LEDs.
Figure 3 - An LED created for the right group. This looks similar to the left group, but notice that the GND is now facing forwards (towards the camera) and up, while the PWR is now in the back.
Step 2 – Prepare an LED from the left group for pairing
Now, take one LED from the left group, and trim the upwards facing PWR and GND about halfway down or so. After this, bend up the DOUT pin as well (this will be the longer of the two pins still pointing down). Cut it a bit shorter than the PWR and GND lines as well. This is now ready to be attached to a right group LED.
Figure 4 - An LED from the left group with DIN facing down, and the remaining three pins up. This is ready to be soldered to a prepared right group LED.
Step 3 – Prepare an LED from the right group for pairing
Take an LED from the right group, and bend up it’s DOUT pin, the longer of the two facing down still. Now, trim the DIN pin about to where the standoff is. It is now ready to be paired with the prepared LED from the left group.
Figure 5 - An LED from the right group that is ready to pair. The DIN facing down has been trimmed.
Step 4 – Pair the two LEDs
Now take the prepared left group LED, and put it on your helping hands such that the three pins facing up are accessible. I use the DIN pin in the alligator clip, but whatever keeps it steady is fine. Carefully pre-tin all three of the upward facing pins, and also pre-tin the DIN pin of the right group.
The most tricky part of the process comes next. Hold the LED from the right group, lowering it in so that the DOUT lines up with its DIN, and the PWR and GND should be touching for each as well. Then solder the DIN to the DOUT, making sure there is about a 2mm-4mm gap from the top of the left group LED to the bottom of the right group one.
Figure 6 - A pair of LEDs with the DIN and DOUT soldered together. Notice the small gapfrom the top of the LED to the bottom pin of the next LED, being about 2mm-4mm. The PWR and GND are now aligned to be soldered as well, which will complete the parallel wiring for those two.
After this, apply some solder to the PWR and GND to the right group one, and then solder the PWR and GND rails together so that it is a secure connection. Be liberal with the application as it should be strong. For those that want to do some light dueling you may even want to come back with some thin exposed copper wire and wrap it around when soldering to strengthen the joint.
Step 5 – Test these pairs
It’s important to test that these two pairs work. Temporarily hook the PWR, GND, and DIN of the left group LED (one on the bottom) to your board, and start the first font. PWR will be on the right side if you have the pairs so DIN if facing down, and DIN/DOUT pair is facing towards you. The wiring diagram is shown below for this:
Figure 7 - Wiring diagram for hooking up 5mm straw hat LED strings. This pic shows a pair but the wiring is the same for any length including the full install. You can hook the PWR/GND wires at the bottom for the full install but leaving the lengths at the top and hooking there is great for testing.
You should see both LEDs light up correctly. If not, check all your connections. I have also had issues where one of the DIN/DOUT pins was destroyed, so if this happens I recommend just tossing both LEDs and starting over. Once they are working put them in your third paired pile.
Step 6 – Build up the string
Once all the LEDs have been paired, it is time to assemble the string. I put pairs together in segments of 8, testing each time I put another pair on the string. I then put completed strings of 8 aside, and then at the end just hooked up each eight until I built the string.
Figure 8 - Two segments of 8 connected together and ready for test. (note this was a case where the top two had gone bad and I removed them but didn’t re-add, which is why there are only 14 LEDs)
The trick is to make sure to test after each segment is added, as when there is a problem it is much easier to localize it to a smaller area if you know the last thing tested good, it must be from the newly added segment.
Figure 9 - The string almost completed. It becomes unruly when near the final length so be sure to handle with care.
After this the string is ready for wiring to your connectors, and then diffusion and insertion into the final blade assembly. Those tasks will be tracked in another tutorial, as they will not be specific for a 5mm straw hat style blade but will be more generic.
Hope this helps anyone that wants to build the NeoPixel string blade. Godspeed, and MTFBWY!