Wave is an Arduino-Compatible Board Designed for Music-Responsive LED Projects

[PioteLLC]

Hi EEVblog!

We're Mark and Steven, creators of BreadBro (www.BreadBro.com). We'd like to share our new project, Wave, with you.

Wave is an Uno R3 Clone designed for music-responsive LED projects. It's a standard Uno with the addition of onboard audio input (3.5mm TRS), a 3-pin JST SH connector configured for use with WS2812B RGB LED (Adafruit "NeoPixel") Strips, and an onboard MSGEQ7 spectrum analyzer IC.

Our goal is to introduce Open Hardware to new people who may have been intimidated by it in the past by including all the necessary hardware to create a beautiful and compelling first project. Hopefully, after a beginner creates a project with Wave, they'll be inspired to create something else - which is why we created Wave as a standalone clone, rather than a shield, breakout, or other form factor.

Some changes are coming to the current prototype as pictured here and on our campaign. Most notably, we'll be introducing a second TRS headphone jack, so that a Y-splitter is unnecessary. We'll also be adding a proper SMD DC Barrel Jack - as you can see, our Gerber files didn't accurately represent a slotted pass-through. Additionally we'll be adding solder jumpers so that you can directly access the audio signal from the microcontroller, for example for use with FFT instead of the MSGEQ7.

Funds from our Kickstarter Campaign are used to buy components and pay for labor costs. Except for producing the PCBs, we do all of our own assembly in a garage in Austin, Texas, using hand placement and reflow soldering. It's slow, but it allows us to do our own QA and be certain of what we're shipping.

We'd love your thoughts on Wave! You can check it out at the following:

Kickstarter Campaign Page: https://www.kickstarter.com/projects/breadbro/wave-0
Our Website: http://www.breadbro.com/
Twitter: https://twitter.com/BreadBroTech
Facebook: https://www.facebook.com/BreadBroTech/

Youtube Video of  an example project built with Wave:

 

[edavid]

I find it irritating when people post so much verbiage about their project and leave out the one thing everyone wants to know... the price.  Do you really expect me to watch your video when I have no idea how much the thing costs?

(It's $29.)

[PioteLLC]

Sorry about that @edavid. I've attached our prices and reward levels, and I'll be sure to include that for any future projects.

We learned how to build electronics using forums like this, and we don't want to be spammy. We post once in each forum we frequent, and really try to approach it from a "sharing" instead of "marketing" point of view. That being said, everything I've read on the topic agrees with your point, that the price should be one of the first things a potential backer sees. We'll be doing that in the future.

Mark

[Kilrah]

Your power supply scheme is not fit for the intended purpose.

EDIT: I assume you still want to learn so I won't say why. If you want hints, explain the way you expect users to use the device (as that may not be sufficiently clearly described in the campaign) and your thought process that led to the choices you made so that they can be discussed.

[PioteLLC]

@Kilrah can you clarify if you're referring to the wall wart or the DC barrel jack?

The DC barrel jack and VIN pin on Wave are regulated by an LM1117. You're totally right that the wall wart won't power Wave through that. However, the 5V 2A wall wart is intended to be connected to a DC barrel pigtail on the LED strips themselves. The LED strips, in turn, share 5V with Wave - essentially identical to connecting a 5V regulated supply to the 5V pin on any clone.

Edit: Always happy to learn! The Wave as pictured is a prototype, and I'm currently working on our production model. I've attached the prototype's schematic. All our products are open source, and we put all the design files up on our site once it's finalized - but this schematic hasn't been proofread for release. Some values may be incorrect and some labels are poorly placed. The "AD7xxx" IC is actually an FT231XS-R.

Edit 2: The thought process behind the power supply was based around the fact that WS2812Bs are power-hungry little fellas. We knew from experience that to create a bright, large display, you needed an external power supply. In testing, we found that Wave could handle 30 LEDs at full brightness with 2 blending channels being used, and could actually run 300 of them at very low brightness. The setup we used for the demo video used our bench power supply attached to a DC barrel pigtail on the strips as I described above, with Wave powered by the 5V power supply coming from the strip's barrel connector.

Mark

[Kilrah]

OK. Then:

- The only power supply method the campaign page mentions is going through the linear regulator from either pins or a barrel jack.
- Your quoted power supply range is 7-12V.
- Some packs include an 2A wall wart, pictured with a barrel jack, with no voltage mentioned.
- All campaign photos show the LED strip connected to the board and no split power cable.

Given the info you provide, the only conclusion we can come to is:
- The DC-jack equipped wall-wart has to connect to the board's DC jack
- The wall-wart has to supply 7V to satisfy the board's min voltage requirement
- Given the WS2812s need 5V, those 7V have to be regulated by the onboard regulator before going to them
- 2A * 2V is 4W dissipation in the regulator, but an LM1117 would overheat at <2W.

If you supply a 5V plug pack and connect it straight to the LED band that's (nearly*) all good - but you'll have to rewrite your campaign page to explain it as the current description shows something that doesn't work. Don't forget the photos if you want to appear serious and avoid further doubts.

*nearly: A 2A 5V pack is enough for 1m of 30LED/m WS2812 strip unless brightness is limited. You supply that same pack for 2m, 5m and 10m kits.

[PioteLLC]

Yep. You're right, I can see where the confusion is coming from, and I agree that's the conclusion to be drawn by our campaign as it stands now. I'll add a new update so it's clear to our current backers, and some more content. Hopefully we'll be able to get the pics you're describing up by the end of the weekend. I'll also try to get some pictures of our test rigs and post those here.

One note is that we do mention the voltage - just not in the image I posted, which was an oversight. It's mentioned in the reward tier descriptions.

All the example code that we're preparing and the curriculum we're writing incorporate the reduced brightness level by default. It was a conscious choice to limit the brightness and the available power in the kits        because it's targeted to beginners. Our thought is that, after they've prototyped their strip on a reduced brightness, they can select a power supply appropriate to their project. However, we were able to run 10m using only USB power on a very limited, but still visible brightness. At 2A, it's not the blinding NeoPixel it could be, but it's still a vibrant display.

Either way, thank you for your input - the whole Power Supply aspect is something we need more content and clarity on.

Mark