TOPIC: Nano biscotte v4 and AV switch help!

Hello, this is my first build with little to no electronics knowledge and my parts are all on order (taking an age to deliver to the UK! There doesn't seem to be much of a sabre scene here). Looking for a bit of advice from the experts, I've held of this long asking for help on the electronics but after battling with it for 2 days I thought it was about time!

I've got this far on my own and made this diagram. Most bits I learned from YouTube videos and forums but there doesn't seem to be anything to help with my specific setup with an NBv4 and a plain old single colour LED. I have read the NBv4 manual but it makes little sense to me. An 'idiots guide' would be nice!





Question 1) Where is best to wire the +ve and -ve ends to power the AV switch? The TCSS videos are great but suggests they should go wherever the main LED draws power. That would mean 3 wires into a single pad which I'd like to try to avoid on fiddliness grounds. Is the recharge port a viable option?

Question 2) I've been told that the NBv4 can now power the saberforge 12w main LED which previous versions couldn't (now 4A per channel but I don't know what a channel is!) Does this mean that the single connection to the board will give the LED all the power it needs? I've noticed there's a spare L2- pad. I have a warrior level SF hilt so I'm reusing the LED module in its entirety and don't plan on taking it apart for more complicated wiring.

Question 3) The LED module already has a resistor on it from SF, will it need to be changed now I'm adding the soundboard etc or can it stay?

Question 4) A dynaohm resistor is recommended for the LED in the switch but this is bulky (it's an arbiter hilt so space is VERY tight). Does a 35ohm resistor sound about right? (3.7 - 3.0 / 0.02)

Many thanks in advance!

From the NBv4 manual if it helps:

Hey there ADstewart,

For the switch, there are four places, or "legs". Two are just the actual switch ones, and it really doesn't matter which side gets what. The two others are for the switch LED. That will need to have +/- figured out. I've done one, and used a dynaohm resistor - they aren't that large. Those wires can go to the corresponding wire coming directly off your LED module, which will require an extra resistor (if it's a mixed colour, the one there is just doing that).

I can't really answer your 12w LED or board questions with any degree of confidence though, since I've never used either.

I've only done two installs myself, but had a pretty good concept of it, and did a TONNE of research.

I'm more than certain that another member who has much more experience will be by shortly, and shoot my post full of holes...lol

Great job doing your first install! Way to go.

Edit: In the mean time, here's a pic of my illuminated switch:

The two blue wires that are twisted together are the actual switch ones, and the red and black are for the LED. That's a dynaohm resistor...

Hello ADstewart,

As Rapine posted do as much research as you can but from what I've seen I thought I had read the NBv4 could drive at 4A too. Shameem Moshrefzedah also has a few good videos of installs which may be of help.
Fellow members Kouri and Jas-Ot are the real go to guys regarding electronics on this forum however.

Regarding the saber scene in the UK, well I am another UK based member (I live on the Outer Rim, and that is isolated!). I do know of a group based in and around Leicester called the Silver Sabres and they hold classes and demos etc. I also know of an Academy in South Wales which is run by Master Sensei Colin Bevan (I think it is still running). I can send you details if you'd like.
I'm not an expert on a lot of this stuff but I've been around for about 2 years now so can point you in the right directions should you need any advice (hopefully!).

kind regards,
For Tyeth

Yes, the NBv4 can handle 4A per LED channel. By "channel", it means the LED pad (L1-, L2-) that is addressable for drive value in the config files. So you can control the amount of current that it gets, from "off" at a value of 0 to "overdriven" at a value of 1023 from the board. The NBv3 (and Pico Crumble) just has pads that give full power all the time, and you'd need to add larger resistors to bring down the amount of current going to the LED (either to regulate it or to mix colors). So a SF LED needed a pretty hefty resistor with the v3's 2A main blade pad.

For the LED in the AV switch, I would follow the "Power Indicator" wiring on pg 14-15 of the manual. That way the LED in the switch would come on as soon as the kill key is pulled and either stay on until it's put back in, or goes off when the saber goes to Deep Sleep.

Looking at the diagram on pg 10, you can just ignore the Power Extender. Everything else should be the same, except you're only going to have one LED negative and you need to add the recharge port (which looks correct on yours).

Hopefully someone a little more versed in the wiring can chime in... I only know as much as I can glean from the manual as well, lol. The layout of the board is still similar to the NBv3, so that manual may have better diagrams for you (since Erv focused a lot on the LED strips in the v4).

Thanks for the nod For.

Excellent KelbornX!

Yes, the way I wired mine lights up the switch only while the blade's "ignited".

KelbornX has pointed out a way to have it "always on".

As I have zero experience with the NB boards, that's really great to know.

(see? I knew someone would come along...lol)

1) Double check the manual. You can use the same contacts as the Main LED if you want the switch LED to mirror the blade, but pages 14-15 in the manual point out two 3.3v pads that work fine for a single accent. Adjust your resistor calculations accordingly.

2) Funny enough, Erv admitted that the on-board mosfets have apparently been fine for a few revisions, but older NB boards had motion sensors that freaked out (phantom swings) if the LED pulled too much power. The new motion sensors are apparently more resilient against voltage ripple, so you're fine popping the 12W+ LED directly to the board. If your LED has one negative line, yeah, just pop that on L1. If it has two, pop one on L1 and the other on L2 - you'll be able to get some rudimentary color mixing based on your LED configuration.

3) Re-use the resistors.

4) I never recommend a DynaOhm on single-cell setups - 3.7v is below the unit's minimum recommended voltage. It'll *work*, if you want something quick and easy, but a properly-tuned resistor will give a brighter LED. If you're mirroring the main blade, I'd say use the battery's max voltage(~4v) for resistor calcs. If you're using the 3.3v pad, use 3.3v for calculations. Sooo 50-67ohm for blade mirror, or 15-20ohm for the accent pad.

No offense intended at all, but why are you trying something this ambitious for a first build? Especially with no electronics knowledge? Have you at least soldered before?

If you haven't soldered before, I certainly wouldn't recommend trying to solder to the sound board first thing. Try joining some wires together and soldering your LED before you try soldering to those tiny sound board pads.

Realistically, my advice is to start with something less complex and then work your way up to the sound install with lighted switch and recharge port. Heck, I've built a few sabers now and I haven't done all of that, and I even learned to solder in high school. Granted, that was 1994, so I actually started with a light only (Warrior tier, in SaberForge terms) for my first build. It didn't go anywhere near as smoothly as the how to video I watched, because people showing stuff on YouTube are experts, that's why they're showing you how to do it. I then took apart some of my existing light only sabers and did some LED swaps and various other things, before trying to do a sound install. My first sound install was a pre-wired Nano Biscotte, I did flash on clash and some other stuff. Then, more recently, I finally soldered a Pico Crumble sound board. Even with a few sabers under my belt, it was a pill to do. Those pads on the Nano Biscotte and Pico Crumble are absolutely tiny, because the boards are tiny.

So, anyway, that's my advice, take it or leave it.

Thanks folks! I'm amazed how quickly people pitch in to help. I don't like to bother people so did as much research as I could but there weren't many guides specific to my setup. I have a grand plan to make a YouTube video of the eventual build to help anyone upgrading a SF warrior level hilt!

So, updated diagram:



I've decided to go with the +ve Switch LED on the deep sleep pad and I've wired the -ve to the negative on the recharge port (partly so there's one less wire to cram in the hilt and partly to avoid putting 3 wires into the -ve terminal on the board. Hope that will work.

For Tyeth - I'm in Newcastle, not sure I'm up for full duelling (I don't want to mark my shiny blade) but I would quite like to learn a few moves so that I can gain the respect and admiration of my peers!

Scifidude79 - No offence taken! The answer to 'why' is basically because I'm impatient. I bought a warrior tier saber and it's just not the same making "whoww" sounds myself. I want a proper saber and I want it yesterday!
I'm settled in my head that I know what goes where thanks to these fine contributors and if the actual build is too hard, so be it. Can't be afraid to try.
The planning part is my weak link but I have some experience with circuits and soldering, I made a few arc reactors a while back (apologies for the cheesy grin)

Hi there ADstewart,

Well if full contact duelling isn't your thing then the YouTube videos from TPLA (Terra Prime Light Armory with Darth Nonymous and Master Nero Ataru) are very good to learn the 7 Lightsaber forms from.

Another person to look up on YouTube is Darth Cephalus, who is also a member here, who has detailed review videos of products and tutorials on Spinning and Tricks (you know the fancy Anakin behind the back stuff...oh and some fire dancing!).

And one final mention goes out to a friend of mine called Master Medwyn of The Distant Earth Knighthood, who has produced 5 lightsaber forms of his own based on the Elements of Planet Earth.

All these can be found on YouTube (if you need links I can go and dig them up for you)

kind regards,
For Tyeth

p.s. sorry I'm late responding I had to go do some online food shopping!

Seeing an issue with the recharge port wiring. I never remember which pins goes to what exactly, but general rule is:

(1) Common Positive
(2) Battery Negative
(3) All other Negatives

No other wires should be on the charge-port contact that BatteryNegative is using. The port's designed to bridge the connection between the two negative pins as needed, isolating the battery when charging.

All of your wires don't need to meet at the board pads - as long as they connect somewhere. Since BoardNegative has to head up to the recharge port anyway, you can have SwitchNegative and AccentNegative meet it at the recharge port and avoid two wires running down the hilt.

For the standard 12mm Offset type RCP:

The "Big" leg is the positive
The inner leg is negative to the board
Outer leg is negative to the battery

If you have a lit AV switch which has a 3v LED, you can get by without a resistor on it if you run it from the accent pads. Those only allow 18ma through, and you won't see much wattage increase with the slight bump in voltage. If the LED in there is rated lower (2v is also very common) you will want to resist it. The LEDs used in the switches typically pull less than 10ma.

While the NBv4 isn't specifically designed for the X4 star it will work just fine. It kind of depends on how your star is built, but if you have a "standard" star that features either all same color LEDs or mixes using two of each color, I would split the two sides between channel1 and channel2. As Kouri said, you could then mix the two colors via the config file.

I would suggest doing a little solder practice before putting the iron to the electronics. You could get a cheap bread board, and just practice getting good joints soldering wires to it. It's not that hard, it just takes a little practice and the right tools/components. Make sure you use Flux, and a good solder. I like to use .6 and .8mm solder for most things, and the biggest wire I typically use is 26AWG. Most installs get 30AWG , but the thicker wire is easier to work with when you are first starting out.

When it comes to your tools, invest some money in them. You don't need to buy the most expensive iron, or other tools, but you should invest in GOOD ones.

Soldering is frankly, an easy skill to learn. The hard part is learning to do it small enough, and clean enough to get everything to fit inside a saber hilt and not fall apart. You will probably make some mistakes, and your first build especially will not look all that great. But that's ok, keep working at it, tear the build down, redo it, etc.

My biggest advice, don't let anyone tell you that you CAN'T do it There's a lot of personalities in the saber world that will look down on anything you do on your own, or if you ask "easy" questions. Don't let it discourage you. Most importantly have fun, and take pride in your work and your finished saber. One of the best feelings is turning the saber on the first time....

Thanks Jas-ot and Kouri

Well spotted on the RCP issue! I actually had it right initially but when I fiddled with my diagram on Pages the black line got knocked out of line and I missed it.

I have some bread board somewhere from long ago when I made a ghostbusters proton pack so I'll definitely take the advice and do some practicing. I'm a bit of a tinkerer and very careful so I'm confident enough to have a good go. I've just set up my work station ready. The parts can't come soon enough!

That's why I love this forum! Someone in need of knowledge reaches out, and the experts respond with their expertise, given without criticism.

Well done!

Let me share a little just because I started a lot like AD did, got impatient and jumped in. Which would have been fine had I been just a tad less impatient and studied up first. I killed three sabers before I decided that winging it was probably a bad decision. So here are a couple tips I've learned.

Plan ahead

Connect the battery last

Don't use too much wire

Put solder on the pad, then solder on the wire, then connect the two

Heatshrink is your friend,

electrical tape is a friend that is always asking to borrow money

Start at the front of the saber and work your way to the back

Don't glue your switch or RCP until you know they work.

Plan ahead

Darth Squidious wrote:
This ^^^. All of this.


Edit: Also, until now, I've been spoiled by larger IDs, and only used 7.4v set ups, so when guys like Jas-Ot or Kouri chime in, I'm learning a lot as well.

So, thanks guys.

Thanks to everyone on this thread who pitched in to help. I finished my saber build this morning and I couldn't be more pleased for a first build.
It's probably not the prettiest internals but the chassis setup was dictated by the extremely limited space in the arbiter hilt. And the was some 'bodging' to be done after I dropped the chassis and broke the acrylic discs, It JUST fits but it works.
Now, which one do I buy next.....

It works, can't ask to much more than that. Nice job!

Excellent job! Glad you were able to get it completed. Congratulations!