Arduino Lightsaber for/with LED string blade

Hi fellow Arduino developers!

After nearly a year of planning, designing, coding and a lot of research in different Arduino related forums I finally finished the first fully working prototype of an Arduino saber for LED string blades.

First of all I would like to thank this great community here for the invaluable support and help in all facets of the development from hardware design through benchmarking to software coding, greatly appreciated! Without the insight you provided this project could not have happened! But it did!
Special thanks to JakeSoft who developed the first Arduino saber for his motivation and hints throughout the development process.

Some words to LED string sabers: if you remember the Star Wars films, you might recall how lightsabers extend when activated and retract when switched off. To better simulate this effect, blades can be build with multiple segments of LED strings, which can be individually controlled by the circuitry. Such lightsaber replicas differ from the so called high power LED implementation, in which the blade is lighted up from below by a single or multiple high power LED dies situated in the hilt of the lightsaber replica.
I started this project after a couple of years gearing up, modifying and building together prop lightsabers. From the beginning I felt attracted to LED string sabers, and looking at the available electronics on the market, I concluded that in certain respects I can do it better. I also set an ambitious goal: implement all features available to high-end lightsaber circuits, with some improvements in the finetuning of the LED segment drives.

The harware can be seen on the following pic (I will create a schemtics and a better description later on):

*** videos are download friendly, a higher resolution version I will upload shortly ***

Please see a video of the "end result":

Here is a short video demo of the breadboard version:

Cheers: ProtoNerd (Andras)

I love it! Well done!

Very impressive. Are you planning on putting together something to show others how to do this?

Yes, definitely I will draw a circuit schematics, I just need to find a suitable programm to do that. Is there a tool use commonly use in the Arduino community to share circuit drawings?

www.expresspcb.com, download the schematic capture tool.
Others might use fritzing.org, but it makes miserable schematics.

EAGLE CAD is another, but a bit of a pain to learn to use. I also would suggest avoiding Fritzing except for the simplest things.

Thanks Crossroads for the suggestion, I downloaded ExpressPCB and made the circuit diagram (not polished yet, but shows everything what is important):

I will add a more detailed description to the modules and why I choose them tomorrow once I got some sleep :slight_smile:
Edit: I also updated the original post to have the pics and videos visible as thumbnails.

A spectacular job.

I'm also making a lightsaber with Arduino ( 80x 5mm green leds, WT5001M02-28P U-disk audio, ultrafire 3,7v 6000mAh x2 batteries)
I have seen the circuit and have a question:
The LEDs are separated by segments which are activated with Arduino through a mosfet transistor...
But... when a part of string is activated.. it's reciving 7,4V?
Is not necessary to use a regulator or resistance to prevent damage?

Hi chivotenkai,

Good luck for your project, it's a worthy one!
As to your question: for that there is a technique to serially connect LED's. That means: I have currently 2 LED string blades, one red and one blue. The blue LED's have 3.4V typ threshold, if you connect 2 in series, you can have 6.8V across them. Actually what I did was to put 2 sets of 5 parallel connected LEDs in series. Advantage: no need for resistances to bring down your voltage, nor for a voltage regulator. The small difference of 0.6V can be managed by the LED's, but you can also adjust the MOS transistor drive to remove the surplus voltage from the LEDs. With the red blade it's even a 3x5 so called serial III. class setup. Big advantage is also that your current consumption will be halved -> longer active time of the saber.

Regarding the WT5001, I also tried that (I will write about it later, that took the longest time to evaluate 3 different mp3 moduls), but I never managed to have a gapless playback, which is essential for realistic saber sounds. The 3rd module I tried was the same used by Jakesoft (WT588D), well I also did not have any luck with that, but he did, so at least it's proven to be able to do that.
I can only suggest to keep the DFPlayer in mind for later...

May I know which batteries you found? 6000mAh capa is tremendous! I also want them...provided they are not too big. In my Arduino saber, or more specifically in the hilt I put in the module I found only enough room for 2x10440, which have only a meagre 350mAh.

WOW
thath idea its great!

I had created the strings 5 strings of 16 leds... so im only need to divide and conect series the string ((8+8) x 5)
consumption only 1A for the leds.
im waiting for the other materials (audio card and arduino nano)
I planned to use dc regulators + NPN transistors but with your scheme , I will manage to save space .

The batteries are a liitle big: ULTRAFIRE 18650 6000MAH LI-ON 3,7V. 66 x 18 mm...
i going to make a hilt similar the luke's saber of episode 6 so i can "hide" that problem.
My idea its to create a video tutorial when i complete the saber.
Even... I have to say again : Thank you for sharing this information

First of all, congratulations !! long time ago, I want to build a sound card for my lightsaber, but was very difficult to me, but, thanks to your tutotrial, like Jakesoft, I have an idea now.
The Question that I want to make to you is wath players have used.
because here in Argentina, it is difficult to get some components ..
Here I get Arduino nano and the accelerometer, MPU6050 ..
but i can not find the player, with that name, DF Player? is ok?
Thanks in advance!!
Gabriel

Hi Gabriel,

This is the sound module MP3-TF-16P aka. DFPlayer Mini I selected after quite a long phase of benchmarking (as you see there has been quite a lenghty discussion about it on the Arduino forum):

http://forum.arduino.cc/index.php?topic=241021.0
http://www.dfrobot.com/image/data/DFR0299/DFPlayer%20Mini%20Manul.pdf

I got mine from a local company but I guess it also gets supplied from Asia, so you could try searching the web. Or you might also look at the sound module JakeSoft used (WT588D).

I read the spec sheet for this sound module. 3W amplifier?! Is that right? Holy cow, that's louder than a Nano Bicotti!

Did you use an 8 ohm speaker? I read the PDF you linked, but the documentation doesn't say what the expected load is for the speaker.

In fact it's louder than any other lightsaber electronics I have (and I have some high ends) :slight_smile: up to the point that for just playing with it you will have the urge to pull down the volume to around 2/3 (code 20 from 32).

So far I tried both 8Ohm/2W (TCSS bass Speaker) and a locally sourced 4Ohm/3W, I cannot hear the difference (am I going deef?), so it can deal with both loads.

BTW, I watched again your MKII Video, especally the part with the configuration. Wow, now that I made mine, the sheer programming elegance you brought in into your saber just astonishes me...I see who is the software expert, software-wise my implementation is like a stone age club in comparison. Did you use the EEPROM to save the setting?

Thanks Protonerd for your answer...the idea is build something with component found here...(in the bestcase scenario..ja..)
by the way, i wanna know, if i use an arduino mp3 modulo...like Wtv020, do you think it is not work?
Sorry, but i am nooby in arduino, and i am still learning, and i dont understand why, only 2 or 3 player ( the MP3-TF-16P,or the WT588D can be work..
GReats!! and thanks!

Protonerd:
BTW, I watched again your MKII Video, especally the part with the configuration.

Protonerd:
Wow, now that I made mine, the sheer programming elegance you brought in into your saber just astonishes me...I see who is the software expert, software-wise my implementation is like a stone age club in comparison. Did you use the EEPROM to save the setting?

Thanks for the compliment, although I think I may have overdone it. The project has become so big that I moved to developing it in Eclipse because it was too hard to manage in the basic Arduino IDE. Also I think I've pushed the RAM limit of the Pro Mini with the features I'm trying to add in for the Mk. IV system. If I change something trivial, it causes what looks like memory corruption issues or outright crashes. I'm going to have to go back and do a lot of optimizing some of the not-so-elegant portions of the code before I can add anything else, or move to a chip with more RAM.

Hihi, cool, you know how hard it was for me to find out why even changing the most unermarkable piece of code caused a totally unexpected behaviour from the saber at a totally different location... it took weeks before it occured to me that probably the system ran out of memory for the dynamic variables. So now I know that in the current state anything I add have to be preceeded by optimizing something else. So Memory IS a great problem with the small boards and only experience is going to tell you that!

@tanakabuki: I do not want to discourage you to use other mp3 players, on the contrary by all means please try them and tell us your findings! This is how I also started and I needed to spend quite a time to go through 3 different mp3 players before I put down my coin beside the mp3-tn-16p. Now with JakeSoft's solution we have currently 2 proven mp3 modules and I would love to see more diversity here. And one more thing: the more people searching for certain features the higher the chance that a commercial solution will de developed for it.

Thanks for the recommendation for the LED circuit.
I'm still waiting for the MOSFET , Arduino and sound module .
but I'm done "led string" (1 cable for V+ and five for mosfet-gnd)

Still not add the light diffuser but I have already tried the brightness with 7.4V
It goes great

Wow, impressive brightness. I take you used green LED's (from the background color, because the string is so bright the camera shows only a glowing white). Greens are anyway the brightest of all LED colors.

How do you lock the LED segments in place? Do you use a stiffener? Or wrap them all in foil/shrink tube?

sorry for answer late...

In the image... only the leds appear in the image.

for the creation of the string i used a similar metod of "Hampton's Hand-Crafted Lightsabers" channel.

But i change a little for make your circuit. I turn led for connect serial: if a string have 16 leds (8+8) in the middle for make the serial conection i solder de V- of the 8º Led to the V+ of the 9º Led.

Next, I Cut the V- of the 9º Led and i use that new space to solder the cable... that cable its directly going to the mosfet. Repeat the process in all strings. If you make 5 strings you have:

5 cables for V-
1 "special" for V+... I use only a cable but i cut it many times for using less space.... conecting the V+ when it have the 7.4V with the next string