Introduction: The OGNITE Flameless Candle - Beta Kit Version

Picture of The OGNITE Flameless Candle - Beta Kit Version

Today we are going to build the beta version of the Ognite digital candle. If you have the version that was distributed at the 2013 MakerFaire in NYC these instructions will still work except that you wont get the fancy debug screen in the last step. 

The Ognite is an experiment in using the *least* technology possible to solve a problem- in this case replicating the visual essence of a candle flame.  It does this using only 40 LEDs and a single chip (and the box those come in). That's it- no circuit board, no resistors, not even wire. The total parts cost is $1.17.

You can find out more about the Ognite at...

Before you start, I want to warn you about a few things...

1) The Ognite is currently a work in progress and not a finished product. Please do not attempt to build this version unless you are looking forward to working though some of the rough spots and sharing your ideas on how to make everything better. Otherwise, sign up for updates on the website so I can let you know when the final version is ready for public consumption!

2) In the rush to get everything ready in time for MakerFaire, I totally screwed up a pile of chips with corrupted software. About half of the kits distributed at MakerFaire had these sad chips, and if you got your kit on Saturday then your chip is definitely one of them. You can still go ahead and build with the sad chips and things will sort of work, but the flame doesn't look nearly as good as with the proper software. You can always piggyback a good chip onto your built Ognite at anytime to upgrade to the latest software.

3) This is project is hard. There are lots of tiny and fiddly bits that have to get aligned and soldered. This is not a good project to try if you are just learning to solder or you get easily frustrated. That said, if like a good challenge than please read on!

Step 1: What You Will Need

Picture of What You Will Need

Step 2: What You Should Have

Picture of What You Should Have

Check out my names for each of these pieces so you know which I am referring to later.

You can free the cardboard parts from the box with a pair of scissors if necessary.

Step 3: Start Placing LEDs!

Picture of Start Placing LEDs!

Fill the first row of holes with LEDs! I like to keep the LEDs in a bowl to make them easier to grab.

Make sure the LEDs are oriented to match the outline on the matrix board.  The orientation flips on alternating rows. The flat on the side of the LED can be hard to see, so I just remember that the LONGER lead is opposite of the flat side.

You might need to wiggle and twist the LEDs a bit to get them all the way though. The holes are a tiny bit undersized, but this helps hold the LEDs in place when you turn the board over to solder on the back.

The matrix board is NOT symmetric, so make sure you start at the bottom row as marked by "1".

Step 4: Solder on the First H-bar

Picture of Solder on the First H-bar

Grab an extra LED from the pile and clip the shorter lead off right above the crimp. We are going to use clipped leads like this for all the connections in this project, so for now on I am going to call these clipped LED leads BARS.

This first bar is going to connect together all the LEDs in the first row. Because the bars that connect rows together go horizontally across the matrix board, I am going to call them H-bars for now on.

Flip the matrix board over and drop the the H-Bar across the top of the leads from the first row of LEDs.

Slide the soldering jig down onto the matrix board so that it is pushing the H-bar up against the leads.

Solder the 5 connections where the H-bar is touches the LED leads. The soldering jig is there to help hold the H-bar in place while you solder it. I like to solder the two ends first to tack them down, and then fill in the middle.

Notice that I also temporarily stuck a spare LED up at the top of the matrix board just to help it sit flat on the table. You want to try to get each row of LEDs as straight as possible when soldering so that the LEDs don't look all cock-eyed when you are done.

If you have the optional Ognite Vanity Flaceplate, you can put that on now to hold the LEDs perfectly straight while you solder. This makes for a impressively uniform final display that will impress your friends. (I did not use the optional faceplate for these instructions partially because I don't want my Ognite to come out so good that it makes you feel like yours is somehow inferior. It is not.)

Step 5: Clip the Leads (Carefully!)

Picture of Clip the Leads (Carefully!)

WARNING: This is the part I mess up the most, and there is no way to "unclip" a lead once you've clipped it- especially since you don't notice the mistake until latter. Think twice and clip once!!!

On the row #1 h-bar you just soldered, you are going to clip the RIGHTMOST four leads and leave the leftmost one unclipped.

Try to clip down low, as close to the solder joint as possible. There will soon be more connections flying above over these and we want room to make sure they don't touch. Clipping down low will also produce longer bars, which will make things easier later on.

Now go find all those leads that went flying when you clipped them (there is one in your Docker's pant cuff). These are not clipped leads anymore, they are now connecting bars and they are crucial parts that you will need if you hope to ever complete this project.

Note that the below picture is taken from the above so you can see everything clearly , but that makes things look inverted. Use the row clipping map attached to this step as your canonical clipping guide.

I know that you are very excited now that your first row is finished and you feel like you know everything you need to know about row assembly. You want to skip the formalities and get down to it and start grinding out the rest of the rows post haste. You are a builder after all, not a reader, and you want to strike the hammer while the (soldering) iron is hot. Don't get ahead ahead of yourself until you read the next step or you will eventually regret it....

Step 6: Solder and Clip Rows 2-4 and Then Add the Bridge

Picture of Solder and Clip Rows 2-4 and Then Add the Bridge

Rows 2-4 are the same as row one, EXCEPT that that in rows 3 & 4 you are going to leave the 2nd column unclipped rather than the 1st column.

Again, keep that row clipping map in front of you because if you (like me) stop paying attention for a minute you'll end up clipping off the wrong lead and then banging your head down onto that tiny bed of nails pointing up at you, causing a bizarre grid of puncture wounds on your forehead that will inspire a series of less-than-flattering nicknames that will linger long after the scab-array has been picked off. Really. I know.

When you finish with Row 4, you are going to slide on the bridge as shown. The holes in the bridge should be on side of the matrix board you have been soldering.

I've missed this step a few times and then realized it only after I finished soldering row #5. It is possible to cut the bridge and get it on, but it is much easier to not miss this step in the first place.

Step 7: Finish Soldering and Clipping Rows 5-8

Picture of Finish Soldering and Clipping Rows 5-8

Keep that map handy, you've come too far to mess up now!

Hopefully eventually I'll print a map directly on the back of the actual matrix board and make all this so much easier.

Step 8: Fold Up the Wings on the Top and Bottom of the Matrix Board

Picture of Fold Up the Wings on the Top and Bottom of the Matrix Board

I used the tweezers to make a clean fold on the scored line. Or, at least I tried to.

They don't have to be exactly 90 degrees, but the closer you can get, the more room you will have in the next steps (especially the bottom wing).

Step 9: Make the First V-Bar

Picture of Make the First V-Bar

Now we are going to connect up the columns. I'll call these the V-bars because they run Vertically.

A single bar is not long enough to reach the full height of the matrix board, so we will use the Bridge to hold the ends of two bars in line so we can solder them together into one long one when necessary.

I try to pick longer bars to make into V-bars so I have more length to work with. I use the longest ones on the bottom and try to have them long enough to overlap the other half at a crossing point.

Stick bars through the leftmost set of holes on the top and bottom wings. I like to use the tweezers to rotate each bar back and forth to help it slide it though the holes.

Try to leave the bottom bar sticking out the holes by a couple of millimeters as shown.

V-bars always run on the OUTSIDE of the LED leads that they cross. They should just barely brush past, but you can bend some of the leads at the base of the LED if necessary to get the V-bars to line up with the holes.

Make sure that the V-bar is not touching any of the H-bars or joints below it. Hopefully you cut those low enough that there is some air between the H-bar and V-bar layers.

You want at least one of the V-bar halves to make it though the hole in the bridge (I usually try to have it be the bottom one), but you don't need to have them both go though if it is a pain. As long as the two bars are touching enough for you to solder them together into one long V-bar it will work.

Step 10: Solder the Leftmost V-bar Into Place Against the Leftmost LED Leads

Picture of Solder the Leftmost V-bar Into Place Against the Leftmost LED Leads

You should have a total of 8 crossing joints (one for each matrix row) plus the lap joint between the two bars (which may be part of one of the cross joints if the bars were long enough).

Step 11: Clip the Leads on the Leftmost V-bar

Picture of Clip the Leads on the Leftmost V-bar

We will clip every lead once it has been soldered to a V-bar. There is no map like with the H-bars. Phew.

I usually solder a full column and then cut it, but you could cut each joint  after you solder it. You should cut a full column before moving on on the next column or else you probably wont have room to get your iron in there.

Step 12: On to the 2nd V-bar

Picture of On to the 2nd V-bar

Note that on the 2nd V-bar there are no leads to connect to on the top half of the matrix board above the bridge, so we only need a single bar at the bottom to connect the full column. This will be true of the 4th column also. Saves us a tiny bit of work.

Feel free to add the unnecessary top crossbar to V-bars 2 and 4 if you obsess about these things and you are worried that people (from the government, sent by the new guy who works in the newsstand in the lobby of the building where your dentist is?) will come in the middle of the night to examine the back of your Ognite looking for top-bottom asymmetry and, when found, will use that asymmetry against you- and not in the "court of law" way.

Step 13: The Rest of the V-bars Are Left As an Excercise for the Reader.

Picture of The Rest of the V-bars Are Left As an Excercise for the Reader.

Now that you are old-hat at V-bar installation, get into the zone and finish the remaining 7 of them on your own. I know you can do this, you just have to believe in yourself.

Try to keep the all pins along the bottom wing sticking out about the same amount.

Step 14: Bend Up Chip Pins

Picture of Bend Up Chip Pins

Order the the chip to lay on it's belly with pins pointing down into the ground. Keep the chip verbally informed of your intended actions.

Use the tweezers to bend up the top-left and bottom-right pins so that they are sticking straight out to the sides.

Try to get this right the first time because these little pins are very fragile and they only have about 1 bend in them before they give up and break off forever. Seriously, if you bend that pin even a bit too far then you mind as well just give up on this project and go home for the day.

Step 15: Attach the Chip to the Bottom of the Matrix Board

Picture of Attach the Chip to the Bottom of the Matrix Board

In this photo, we are looking at the bottom wing of the matrix board. The bottom is the side below LED row #1.  The notch on the chip is facing to the left (and again very hard to see in photo).

The holes on the bottom wing of the matrix card have flat slots just below the v-bars that should perfectly accept the pins of the chip and perfectly align them with the waiting V-bars. If not, then just jam it in.

Note the unused hole at the far left of the wing. I'll get rid of that hole in the next version of the matrix board.

Solder the v-bar tips to the chip pins. If some of the v-bar tips are sticking out too far then clip them unceremoniously.

Step 16: Solder a Bar Onto Each of the Bent Out Chip Pins

Picture of Solder a Bar Onto Each of the Bent Out Chip Pins

The best way I've found to do this is to put something on top of the crossbar to hold it while I solder. The handle of a wire clipper works well, while a Big Wrench is too big. True Story.

These sticking out bars have now become our power rails.

Step 17: Bend the Sticking Out Power Leads Down Into the Battery Case

Picture of Bend the Sticking Out Power Leads Down Into the Battery Case

Go find the bottom of the matchbox that your Ognite came in and turn it face down. This is now our battery case.

Put the matrix board on top and make right angle bends down on the power rails so that they precisely go down though the tiny holes allotted for them and into the battery case.

It is so simple a child could do it.

Step 18: Removal of the Offensive Visible Bridge Front Section

Picture of Removal of the Offensive Visible Bridge Front Section

Now that all the V-bars are firmly in place, the Bridge is superfluous. Unfortunately it has become so intertwined into the fabric of the surrounding circuitry that it is unresectable for all practical purposes. We can however excise the portion of the Bridge that is superficially visible on the anterior of the display. The procedure involves lateral incisions along the marked girdle lines, followed by careful removal of the now free bridge section.

Step 19: Battery Contacts

Picture of Battery Contacts

add battery contacts in the box. dont mess it up.

listen, so far i think ive been pretty cool about working with you and trying to get this thing done but im getting tired.

if you cant put in these battery contacts on your own without me holding your hand and pointing out each and every little detail then there really is not much more for us to say so maybe this wasnt a good idea and maybe it just isnt going to work out and no hard feelings...

Step 20: A Brief Interlude

Picture of A Brief Interlude

And now, gentle reader, we must pause for a moment.

We have come a long way together on this journey. You have had ample opportunities to quit, but you stuck with me and for that I am grateful. A lesser partner would have given up long ago, but you are better than that. That makes what I am about do now all the more difficult.

First a note for anyone out there who may have a relationship with me outside of the Ognite world. If our kids go to school together,  if I am the trustee of your legacy foundation, or if we once dated in high school, then I urge you to close this browser window now and abandon this project. If you continue, any trust or respect or affection that you may once may have felt for me will be irrecoverably destroyed. It is not worth it.

Step 21: Unforgivable Fraud

Picture of Unforgivable Fraud

Find about a square centimeter of aluminum foil. I used the corner of a piece of foil that once covered a slice of to-go pizza.

Divide the foil into 4 sections and fold each those so that you end up with 2 short ones and 2 longer ones- all about 1cm high.

Put one short piece behind each of the power rail terminals, and arrange the longer ones so that they will connect together the adjacent battery ends.


I know that I just told you to find some aluminum foil. I know that there was no foil inside the kit. I know that this fundamentally destroys the entire point of this project.  You think I don't know this? You think this has not been the singular thought in my mind since I realized the inevitability of my current situation? I know.

In theory, that battery contacts made from bars should work as well as any other battery contacts in the world. Unfortunately, in practice, they just failed. I don't know why. I've tried every possible shape and size and position and orientation, but it seems that the harder I try the worse the contact.

And so we have the foil. Practical, efficient, effective, and invisible to the lay viewer. A useful lie with no easy way out.

So where does that bring us? Now you know the dirty little secret. You are part of this now, as guilty as I am.

What are you going to do? First, you are going to put the foil in the box. You are going to insert the batteries accordingly. You are going to place the box face down on a high shelf. You may even add a hand lettered sign saying something to the effect of "Fraigle: Please do not touch!!!!" to dissuade the curious.

Next you are going to thinking about a long term solution. You've got about 2 weeks before those batteries go dead and you need to lift that box up. You are smart. That should be plenty of time to figure something out.

You need to figure out a way, any way, to get those batteries reliably connected to that matrix board without trickery and deceit, adn do it using only the materials in the Ognite kit (the rods and laser cut cardboard). You'll need to think LITERALLY out-of-the-box. I'll support you anyway I can. I'll send you as many green kits as you need. I'll laser cut any file you send me.

We can do this. Once you figure it out, I will quietly update and backdate touch all the build files and no one will be any wiser. It will be as if none of this ever happened. I'm counting on you, don't let me down.

Put your ideas here:!categories/ognite/battery-holder-ideas

Step 22: Insert Batteries....

Picture of Insert Batteries....

Insert 3xAAA batteries. I usually have most luck putting installing the center battery first, then putting in the side ones with the end that connects to the power rail going in first so it pushes against the rail. .

The rail that sticks out the front of the matrix goes to the positive side of the batteries, and the rail on the back goes to negative.

There should be 3 volts - 4.5 volts coming out of the batteries depending on how old they are. The Ognite can actually run on anything between about 2.1 volts and 5 volts. More than 5 volts will blow out the chip, and less than about 2.1 volts and the LEDs won't light up.

Step 23: Diagnostic Scan Screen

Picture of Diagnostic Scan Screen

As soon as you connect the batteries, your Ognite should spring to life!

The first thing it will display is the Diagnostic Scan Sequence. It will individually turn on each LED starting in the lower left corner and working it's way left-to-right then bottom-to-top. Once all the LEDs are on, then it repeats the pattern turning them all off again.

This gives you a chance to make sure that all your LEDs are connected correctly.

If you see an LED that just won't light (as shown in the photo), then get out your soldering iron and fix the cold connection to that LED.

If a whole column or pair of rows doesn't light, then check the solder connection for that row/column to the chip leg.

If you see the LEDs come on in the wrong order, or skipping rows, then you probably made a mistake following the map. Don't say I didn't warn you.

If you don't see anything, check the batteries and their connections.

The pattern will run though once each time the Ognite powers up, so to see the pattern again just disconnect the batteries and reconnect them again.

Once the diagnostic scan finishes, the Ognite will automatically jump into flame display mode!

Step 24: ...and Enjoy!

Picture of ...and Enjoy!


Post a photo of your work in the Ognite gallery here:!categories/ognite/build-gallery

I'd also welcome any suggestions on the design or instructions.

Thanks again!



dunnos (author)2013-09-26

Oh my god I need one of these :o

edwin_n (author)2013-09-26

OMG I Loled when I saw this at maker faire. Working on second one now. Congrats!

SoundTechie2007 (author)2013-09-26

Absolutely phenomenal project. Your writing style is great and your instructions are simple. Even though I wasn't at MakerFaire, I found myself wanting one of these kits to follow along. I've soldered up LED matricies before but you've presented such a wonderful and clean way to do it! Congratulations on a fantastic project.

Gwolf (author)2013-09-24

Excellent project, blew my mind at MakerFaire

gwlinn123 (author)2015-03-06

Nice work bigjosh! I've ordered the parts via Ebay from China. There is often free shipping but you have to wait a month or so to get your order.

Since I intend to use this outside, I'm thinking about using my 3D printer to generate a "plastic", ABS, cardboard. I don't see any dimensions for the LED mounting holes but I'm guessing that the distance between vertical columns is driven by the chip pin spacing and it is the same for the distance between horizontal rows. Is this correct?

Recognizing that you have to consider assembly difficulty, do you think that the display would be any better if you just "crammed" the LEDs as close together as possible? To do this, I would cut a PWB. You can get small lots of small boards from China for next to nothing. Again, several weeks of waiting time.

I know one of your goals is "cheap". One of my goals is "reliability".

Again, thanks for your work, Gary

DrWass2 (author)2014-02-13

I tried to contact you after the maker faire in ny last year.. but must have been lost in the ether. Anyway, I think a dab of "conductive " glue would work great on the battery. Yes, its another thing, but you already use solder. Maybe you can replace all the solder with conductive glue, then you wont need an soldering iron etc.

starting to get real minimal...pliers, cutter, conductive glue, and your parts!

ps. the chip you gave me at the show had the wrong program in it. How do I get the correct program into the chip or replace chip good program?

keep up the good thoughts..


aliasjanedoe (author)2013-11-30

This is so brilliant. I must have one! :)

Idea for possible improvement: include a sheet of something for diffusion which can stand in front of the LEDs. I know it's another item, but it could add that little bit more realism. Just try draping a tissue over it to see what I mean.

DrWass2 (author)2013-10-25

Have you tried "conductive Glue" to take care of the battery problem.
You already use solder so why not glue!
I don't know how solderless versions works but conductive glue there also would work!
saw you at maker faire 2013 NYC

astral_mage (author)2013-10-06

u said there be no. or circuit board an your using one? also if u included a ic socket. the ic chip could be replaced an upgraded as necessary as well.

bigjosh (author)astral_mage2013-10-24

The socket would cost more then the entire project!

Luckily there is no need for extravagant DIP sockets - you can upgrade your Ognite to the latest firmware anytime via the backpack method shown here!

teknojo (author)2013-10-23

Have you considered setting up a solar cell (the same surface area of the box) with a li ion battery set up? Allow the sun to charge it during the day and become "candle light" at night?

I know that adds to the complexity of the project, but it would be nifty to take sunlight and make it into candle light.

EET1982 (author)2013-10-10

Pretty cool idea. Thanks for sharing :-)

DragonDon (author)2013-10-06

Way cool. Can't wait till I try my hand at some sort of LED matrix setup!

astral_mage (author)2013-10-06

oh nooos we have a dead bug now!!

astral_mage (author)2013-10-06

use a dip socket thier cheaper that the chip . oh the way wat the orientation. wich way is the half moon pointed to?

mrshirls (author)2013-09-26

Where is the video of the "flame"?

bigjosh (author)mrshirls2013-09-26

I've tried, but no camera that I own can figure what to do with a bunch of tiny bright lights all randomly making millions of very, very brief (on the order of 1 microsecond) flashes. Your eyes, of course, just see the flame... :)

I hope to get a javascript simulator up on the website, but some things you really just have to see in person...

riff raff (author)bigjosh2013-10-06

Maybe set the camera to "manual" and experiment with longer exposure/shutter times?

jgreenburg (author)2013-10-03

This is clever, I enjoy minimalist projects involving electronics.

I like that you used a chip, but is there a way to do this with a simple oscillator and some kind of random generator? (zener diode over flow maybe?)

It would add more components but reduce the necessities to build it. i.e. programming

jgreenburg (author)2013-10-03

haha, At least your honest.

Lance Reichert (author)2013-09-27

Where can I get one of these kits?

How much current does it draw? I'd like to replace the commercial batteries with a stack of eight copper-clad zinc pennies. (The seven interfaces each produce about 0.7 V.)

Lance ==)----------------

bigjosh (author)Lance Reichert2013-10-01

Check out...

...for more info on how to get one.

I *love* the idea of using the existing cardboard with pennies to make a pile battery, but I don't think it would be able to generate anywhere near the (even small) current needed. The Ognite draws about 20ma@3v when an LED is lit.


maggiemcfee (author)2013-09-29

My idea for the battery problem is to make a battery box within the battery box and add a small strip of thin metal to the kit (the current box would need to be slightly larger so as to accommodate it). This way the outer box will force contact between each metal stip and the LED wire contacts. Here's a general outline image

rangerweavere (author)2013-09-27

Where ca I get one of these?
This is so awesome!!

bigjosh (author)rangerweavere2013-09-27

Check out...

...for more info on the project!


kewpiedoll99 (author)2013-09-26

Very detailed and great instructable, with terrific photos. One question: In step 6, you say "When you finish with Row 4, you are going to side on the bridge as shown." Did you mean "slide"?

bigjosh (author)kewpiedoll992013-09-26

The bridge has a slot cut in the middle of it and the matrix board fits into this slot. It is a tight fit, so you have to slide the bridge down to the middle of the matrix board. LMK if this is not clear and I will come up with some better way of explaining it. Thanks!

kewpiedoll99 (author)bigjosh2013-09-27

No, no, it was only unclear because you said "side", not "slide", up above in the text.

bigjosh (author)kewpiedoll992013-09-27

Apparently that typo was as invisible to me in comments as it was in the text... :)

Fixed now. Thanks for the (multiple) heads up!

alcurb (author)2013-09-27

I can't seem to find the demo video for this project. Where is it?

Dream Dragon (author)2013-09-24

Looks like an interesting project, and I see that there's a few things that you still need to iron out before you can call it a finished product.

You are looking for ideas to improve the battery holder? How about using a piece or a couple of pieces from a soft drink can/beer can instead of aluminium foil? That would provide better support and be more robust.

A real candle flame only really moves when there's a draught or some other movement. If you added a small spring (like you might find in a pen) and a pin you could make a tiny vibration sensor that could be used to input values to the processor that might help generate a simpler "flame".

I really like and appreciate what you are attempting to do here, and I look forward to hearing about further developments.

bigjosh (author)Dream Dragon2013-09-26

Can chunks would work too, but one of the main ideas of the project is to use the *least* amount of stuff possible, so I'd like to find a solution that only uses the parts already in the kit.

I'd love, love, love to make the flame reactive to the environment. Maybe instead of a spring, having a rod somehow hanging free so that it can touch another part when pushed by wind? Or maybe use the chip's ADC to sense the capacitance of the hanging part?

It could also be possible to have it react to changes in ambient light by running the existing LEDs in photo diode mode.

To do either of these, I need more code space (4K is currently 100% used up with just playing the flame image). Would love help from anyone who can come up with a more code efficient way to generate the flame to free up room for these and other features!


Dream Dragon (author)bigjosh2013-09-27

Ok, I see where you want to go with it and I really like it. I hate the normal kind of flickery candles that use "Music Chips" and just flash one LED in response to the current generated by the music, but a SIMILAR solution could be used here.

Coding is definitely not my strong point, I struggle with the electronics sometimes, but it seems to me that you really need to loose the video and work with some kind of internally generated "flame". At the kind of resolution you are working with a simple triangle would be close enough. If the centre of the bottom row (1,3) is the BOTTOM POINT of the triangle, you only need to define the other two points. If you think of the grid of LEDs as two groups of 5x5 (yes the two groups would overlap) you may be able to define BOTH points using the same pair of numbers.


Define "a" as a random number between 0 and 5
Define "b" as a different number between 0 and 5

Make "top point" x = a + 4, y = b

Make "bottom point" x = b, y = a
Make "bottom point" x = 5 - b, y = a
Make "bottom point" x = b, y = 5 - a
Make "bottom point" x = 5 - b, y = 5 - a

Does that make sense? You may want to define a third variable to decide which bottom point set to use, and I honestly don't know how you address the pixels in that particular application, but with any luck that'll give you a start.

As for making int "environmentally reactive" I think you'd need to find make or add a sensor of some kind. Detecting ambient light is certainly interesting, but probably not very useful for a device that gives OUT light. Detecting Capacitance is also a clever idea but would only apply if you the capacitance changed often (as in the example you mentioned).

Adding a mic may very well give you LOADS of options for environmental sensing, but would also add to the component count and complexity of the project.

bigjosh (author)Dream Dragon2013-09-27

I see two possible great new features that could come from environmental light sensing.

First would be on/off control. Right now the only way to turn off an Ognite is to take out the batteries. Luckily Ognites run for weeks (soon to be even longer), but if the Ognite, say, automatically turned on when it saw darkness and then automatically turned off an hour later then the batteries could last years. You could also possible turn on your Ognite on demand by just waving your hand over it to create a shadow. I think that would be cool!

Second would be to possibility of using Ognite's twin light sensing/generating abilities as an inter-unit communication mechanism. With Ognites being so cheap, it might be desirable to have *lots* of them, and it would be really cool if they could all automatically discover and talk to each other to synchronize their flames into a choreographed display!

bigjosh (author)Dream Dragon2013-09-27

I've played with many algorithms for generating the flame. The most promising are physics-based and model the flame as a set of moving particles, which many people have done impressive work on. (Google "particle simulation flame").

Unfortunately, while all these models look *great*, so far I haven't found one that looks *real*. The flame looks like a game flame, not an actual flame. Your brain knows the difference. There is something special about the motion of the real flame that is not yet captured in the models (at least the ones I've played with). When you look at the Ognite, something about it just *feels* real. It is almost magical, especially when you remind yourself that the illusion is being created by just 40 blinking dots.

I'm hoping that someone can help me find a model that will replicate that magical *real* feeling, but until then I'm sticking with the video.

There is another sort of opposite approach to flame generation that I am also interested in. I call this "parametric" flame production. Rather than starting at the bottom with a physical model of a flame, it starts at the top with lots of real-life flame videos and statistically works its way down looking for patterns that describe the actual flames. The hope is that you can find a finite set of flame "modes" and "transitions" between those modes that are present in real candle flames, and then just store these rather than the whole video. Done right, it could capture that "magic" realness while still allowing for very efficient storage and even spontaneous generation of a non-looped flame.


One additional thing, would it be easier to put the "H-Bar" on one side of the card and the "V-Bar" on the opposite side? It might help to clarify instructions and improve the separation of the different sides of the circuit.

bigjosh (author)Dream Dragon2013-09-26

I have a table full of prototypes doing just that!

On the solder version, it is very hard to get the LEDs close enough to the card while still leaving room for the soldering iron to get in there.

Having the h-bar on the front of the card *does* work on the solderless version.


AJMansfield (author)2013-09-26

The solution: solder directly on the batteries, of course! Use two spare bars to solder the three batteries together in the correct order, and then all you have to figure out is the contacts that connect to the chip...

bigjosh (author)AJMansfield2013-09-26

I've tried and it just doesn't work well for me. I can fuse weld onto the battery terminals and it works great, but I fear that there is a (small) segment of people don't have their fusion welders handy... :)

Play with it and let me know if you can get it to work!



AJMansfield (author)bigjosh2013-09-27

More likely, your soldering iron is just too cold. The iron is not just for melting the solder; the point is to get the work piece hot too, and in the case of batteries, you need the iron to be pretty darn hot to be able to heat the terminal up fast enough to solder before something else melts or bursts. Seriously, just crank the heat up a little and it should work fine. (The other possible problem is the solder type; the easy solution is to just use some lead solder for this part).

svarghese1 (author)2013-09-26

Those three batteries are not sufficient for the 40 LED's you've put... Need to find a larger power source...

bigjosh (author)svarghese12013-09-27

That would be true in a traditional design, but the Ognite is not a traditional design!

There is only ever a single LED on at a time, and each LED is only turned on for about a microsecond at a time.

In practice, 3xAAA batteries run the Ognite very well for several weeks. I hope to at least double the power efficiency though some software changes that dynamically turn off unused parts of the chip.


ihart (author)2013-09-26

What a great project. Can you include a video, parts list, schematic and code?

bigjosh (author)ihart2013-09-26

Parts list and code are available on the website. I've tried doing a schematic, but it is hard to make one that really explains what is going on because the circuit is in 3D. Maybe I will try again when I have a chance or post some of my failed attempts. It is hard to capture what it really looks like in video (at least with any camera I own), but I would like to eventually get a javascript simulator running on the website.

SeedRally (author)2013-09-26

So far, I've actually been clipping the leads before I push them into the slots. I don't have good wire clippers hence why I'm doing it this way. With some intense focus I've been able to not mess up.

bigjosh (author)SeedRally2013-09-26

That works great, and in the solderless version of the kit the leads all come pre-clipped. The only downside to pre-clipping that I can't really see the flat side of the LED without magnification, so I orient the LEDs use the longer lead. Thanks!

AJMansfield (author)2013-09-26

Deliberately bending pins on a DIP!?! This is HERESY!

AJMansfield (author)2013-09-26

You know, if normal solder flows bad for you, either your iron is too cold, or you should try using some sort of flux compound.

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