LED Hanukkah Menorah

I wanted to make an LED menorah for a friend. In planning this I decided I wanted to keep the parts-count very low and use components I had on hand. I think I have achieved my goals and couldn't be happier at the outcome of this project.

Please visit my webpage for more on this and other projects:
http://jumptuck.wordpress.com

Disclaimer: I am not Jewish. I have done a bit of Internet research about the Hanukkah Menorah in order to learn the principles behind it's design, and how the candles are lit. I respect this religion and mean no offense in the case of any errors I have made regarding this tradition. Please contact me and I will be happy to make changes to this instructable.

Step 1 The Design

In the design process I set several goals:

• Controlled by an AVR ATtiny13
• Interfaced with 1 push button
• Driven by ~3v of unregulated power
• Incorporate an auto-off function to simulate the candles burning out each night.

I chose the tiny13 because I had several on hand just collecting dust. In order to control 9 leds without a shift register (a separate part) I needed to implement a charlieplex.

A schematic is available below.

For those electrical engineers reading this, I have two points to make:
1. I did not use a pull-up resistor for the reset pin, it is left floating. This is not a critical application so if we have a random reset it's not the end of the world.
2. I did not use a decoupling capacitor because I'm using unregulated power and I don't think it's essential.

Comments

[bumsugger]

Er,what precisely IS a Hanukkah Menorah????????

[godofal]

hanukkah is a jewish holiday, and a menorah is is a nine branched candle stand used on that holiday.

somehow its gotten quite popular among elektronics and kits...

[Alyakpink]

NO IT ISNT!! a menorah only has SEVEN candles, 1 4 each day of the week!!!!! a HANNUKIA is wat u use 4 hannuka w/ 8 candles and a shamash (the 9th 1)!! i HATE it wen ppl make this mistake!!!!!!!!!!!
but nice instructable btw

[accamel]

hahaha. You're blatantly wrong. A menorah has 9 candles and they are lit in succession, adding one to the number of lit candles each night of hanukkah. There are 8 days of hanukkah; the 9th candle is the one that you light with a match and then use to light the 8 others. Hannukiah is just another name for a Menorah. Get your facts straight.

[asitnik]

There are two menorahs; the Temple (as in Jerusalem Temple in the Temple Mount) menorah, and the Channukah menorah:
http://www.chabad.org/library/article_cdo/aid/1358679/jewish/Is-MY-Menorah-The-Same-As-THE-Menorah.htm
:-)

[agis68]

we got Xmas after all and nothing else....so simple...;D

[godofal]

relax mate, i didnt say that to upset anyone
not everyone knows everything ;)

[Alyakpink]

ok, ok, sorry.

[bumsugger]

Oy vey already......................vot a nice little toy!

[godofal]

i like this, im going to make one tomorow, that is if i manage to get eagle to work, and i can make a nice adjustment im planning on.
il upload pictures if everything worked out!

[godofal]

oh, and 1 more thing, why are u using only 4 resistors for 9 leds?

sry if its obvious (like in the code/some leds in series) i havent looked at the details alot yet...

[raykholo]

I love the idea One suggestion i could make though, if you were willing to make a two sided board, would be to use a battery holder with pc pins and solder it onto the back of the pcb. It should be able to stand up by itself your way is also very interesting, however i would have shortened the wire and terminated the connection myself, also using hot glue instead of a rubber band. Just some advice to the aesthetics of the design

[geeklord]

Ok, so im trying to figure out AVR programming, and these "<< or >>" keep showing up, mainly in the PORTB |= (1<< something) and PORTB &= ~(1<< something). I know that they are used to set bits without setting the other bits (right?). Can anyone explain a little further how you do this?

[barney_1]

This is the shift operator: << it means to shift this bit a number of places left or right. The first thing you should read is the "Programming 101" tutorial on avrfreaks.net. Read it and know it; you will never have problems with bit manipulation. Here's a link:

http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=37871

[geeklord]

k, thx

[LastDevil]

May i just say that i have only just started on electronic and you have or anybody that knows how to create a pcb are very skilled i just can't get my head round it yet i might do in a few years ;-)

[AnarchistAsian]

very nice! maybe some time i'll make some for jewish friends...

[lrooff]

Excellent idea and execution. May I suggest patenting it and marketing it. While some of us insist on actual flames for the lights, there are a number of accepted authorities who permit electric lights as well.

[barney_1]

I'd love to patent it and make a million dollars. Unfortunately this is not in the spirit of the Free and Open Source Software movement. Without FOSS I would not have been able to learn how to do these sorts of things and so I give back with this project. I hope others can learn from it, develop their own projects and share them with others.

[Yerboogieman]

Well said.

[Kiteman]

I don't believe it is patentable, since similar projects and kits have been available for some time.

(Example)

[AnarchistAsian]

meh, this one is better! and if it's a different design, it can have it's own patent, right? but it doesn't matter anyways, because it's on this site now...

[Kiteman]

I wasn't debating quality, merely pointing out that the idea (an LED menorah controlled by a microcontroller) had been done before. Certainly the design used here, and the layout of the PCB, can be copyrighted, but no new processes are involved, so it can't be patented. (I may be wrong, but that is how I see it)

[lrooff]

I wasn't aware that anyone had produced something like this before. But, then, my personal menorah technology level has only recently moved from oil lamps to candles... In any case, mazel tov to barney_1 for an excellent project.

[AnarchistAsian]

wait, can't you patent a single device made up of older technology?

companies do that right? taking old ideas, but making new products?

[Yerboogieman]

This would be perfect for cell phone batteries. (i've been building stuff with a bunch of old cell phone batteries people give to me.)

[barney_1]

The problem with that is you should have monitoring circuitry for those types of lithium batteries. If you run them down too low you will not be able to recharge them again.

[JakeTobak]

If you could keep the lights lit constantly for the 8 days/nights, then I think that would be good I think. I'm a Jew, but my family never really practiced, so I'm not sure on what the rules are either :P I think it would be kewl to attach a magnet to the back and it would be a nice fridge magnet, would be a nice little filler gift (kinda like a dreidel).

[barney_1]

From what I've read the important thing is that it stays lit for no less than 1/2 hour. If you wanted it to remain lit for 8 days that's not a problem, the auto-off function can be disabled in the Interrupt Service Routine. I'm not sure how long the battery would last. I believe it uses about 2.2mA when all 9 leds are illuminated. You should be able to calculate battery life from there. (if you are interested, I read about 1uA of current draw when the device is in sleep mode)

[JakeTobak]

Sorry, didn't notice the huge battery pack, maybe you could use watch batteries, idk how long they'd last, or something to make it smaller for my idea to work.

[Kiteman]

A very thoughtful gift. Perfect for small, fire-risk spaces like student digs or your locker at work.