Another countdown timer gauntlet using an Arduino

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Elkman

New Member
I've been working on a countdown timer gauntlet of my own, similar to MasterAnubis' design. (Thanks for the inspiration.) First of all, here's the sculpt for the base:
Left%20Gauntlet-001-600.JPG

It's made from wood, instead of clay, so I could get it nice and flat and so I could carve out those windows nice and square. The components on top are surface-mount ICs, a few capacitors, and other parts from those CD-R drives I've torn up. They aren't 100% movie accurate, but I wanted to put my own little stamp on the project.

Here's the circuitry I built:
Left%20Gauntlet-034-600.JPG

I used an Arduino microcontroller hooked up to a MAX7219 LED display controller. The 7219 is made to drive display matrix boards or LED digits, so I used it to drive my own digits. I built those from rectangular LEDs I bought from Digi-Key. The 7219 is fairly straightforward to work with. The anodes of each segment of the LEDs are hooked up in common to one of the segment pins on the 7219, while the cathodes of each digit are hooked up to one of the digit pins on the 7219. There's a library of Arduino code to control the 7219.

Here's a picture of the cast plastic part with the LEDs all lit up:
Left%20Gauntlet-028-600.JPG


Finally, I painted the plastic casting, added a smoke-color plastic window, and put some paper inbetween the LEDs so the circuit board isn't visible. Here's the finished product:
Left%20Gauntlet-032-600.JPG


I posted a video on YouTube that shows my countdown timer in action. You can also hear me mispronounce "Duemilanove".

Left%20Gauntlet-001-600.JPG


Left%20Gauntlet-034-600.JPG


Left%20Gauntlet-028-600.JPG


Left%20Gauntlet-032-600.JPG
 

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Darkshrine

New Member
Brilliant. I've nearly completed my wristbomb but I'm going to leave the screens dark (lack of electronics talent see).
Fantastic work
 

pill baxton

New Member
great work! You should consider posting a easy to follow step by step guide for the electronics,Im sure it would help alot of us hunters.
 

MasterAnubis

New Member
Excellent!

Way to step up the game! Great look with the rectangular LEDs and it looks like you have enough room for a 9v battery too.

Thanks for the 'props'. It makes me feel good to know that I'm inspiring. I have throw out my own thanks to Honus for getting me into the Aurduino and el'luj getting me in gear on the timer.

I'm going to have to make mine look better now.
 

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Elkman

New Member
Hi Elkman, which Arduino microcontroller did you end up using for this project if you don't mind my asking?
It's an Arduino Duemilanove, which is the blue board on the left in the second picture. SparkFun Electronics also sells a number of other Arduino kits and supplies.

I'd be willing to share my wiring diagrams and source code, although I'm kind of pressed for time with my current costume project. I only have a month to go before the convention where I'm presenting it. (Ack!)
 

oneuglymf

New Member
if you would be willing to share that would be wonderful. I'd love to put a similar setup toeghter with help from someone locally whom I've shown this and a couple of other threads on the lair. Such great work, I don't want to copy it, but imitation is the sincerest form of flattery IMO. LOL!
 

MasterAnubis

New Member
I just wanted to add that I have ordered from Makershed.com and Adafruit.com as well as Sparkfun.com.

http://www.makershed.com/SearchResults.asp?Search=arduino
http://www.adafruit.com/index.php?main_pag...keyword=arduino

These companies shipped when they said and have got the stuff to me quickly. :)

They don't stock the exact same accessories either because they have some of their own stuff mixed in.

This is the kit I started with. It's great if you want to mess around with different configurations and to get familiar with the Arduinos capability. The source code for each experiment is provided in the pamphlet and also online to cut and paste.
http://www.adafruit.com/index.php?main_pag...products_id=170


Youtube was a little helpful for ideas but that's about it.
 

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Elkman

New Member
OK, I finally got a chance to draw up the wiring diagrams. Here they are:
segmentwiring.png

MAX7219wiring.png


The diagrams don't fully explain what's going on with the segment wiring, so I'll explain it more here. Basically, the Arduino drives the MAX7219, which thinks it's displaying some 8-segment LEDs like you'd find on a pocket calculator. Instead, it's really driving a digit constructed of LEDs in each of the four windows here. The cathodes of all of the LEDs in each digit are wired together and connected to one of the "DIG" pins on the MAX7219. Meanwhile, the anodes of each segment on each corresponding digit are connected together, and then connected to one of the "SEG" pins on the MAX7219. For example, the top right segments on all four digits are connected together with yellow wires to the SEG B pin on the MAX7219.

Finally, here's the Arduino source code. I've mapped the digits from the Yautja font to the pins used on the MAX7219.

If this all seems complicated, ask me any questions and I'll try to explain it some more.

I'm considering building and selling these gauntlets, or the standalone displays, but that'll have to wait until mid-July before I have time to make any more of them.

segmentwiring.png


MAX7219wiring.png
 

tommynator1024

New Member
Elk, that's some massively impressive work here!! Really like the final look of the whole product!

One question: what would it take to make the four individual windows display different digits? I think you said you wired all LEDs of the same letter to the same input/output pins, meaning they count synchronized.

Oh, and one more thing - in the twinkle() method you set the LOW twice in a row towards each end and begin of the for loop. ;-)
 

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Elkman

New Member
Elk, that's some massively impressive work here!! Really like the final look of the whole product!

One question: what would it take to make the four individual windows display different digits? I think you said you wired all LEDs of the same letter to the same input/output pins, meaning they count synchronized.

Oh, and one more thing - in the twinkle() method you set the LOW twice in a row towards each end and begin of the for loop. ;-)
It wouldn't be difficult to make the four windows display different digits. That would just be a change to the code. For example, instead of this:
[codebox]lc.setRow(0, 0, yautjaDigits);
lc.setRow(0, 1, yautjaDigits);
lc.setRow(0, 2, yautjaDigits);
lc.setRow(0, 3, yautjaDigits);
[/codebox]
I could do something like this:
[codebox]// Set the display to 2368
lc.setRow(0, 0, yautjaDigits[8]);
lc.setRow(0, 1, yautjaDigits[6]);
lc.setRow(0, 2, yautjaDigits[3]);
lc.setRow(0, 3, yautjaDigits[2]);
[/codebox]
I just haven't had the chance to write the code that counts down with different digits. If I counted down from 10,000, then the leftmost digit would read 9 for a very long time, and people would think that it wasn't actually wired to anything.

Oh, and that twinkle() method was just there for my debugging, since I was trying to figure out a wiring problem. I don't even have that LED wired up any more, so it doesn't matter if I set it to LOW twice. ;)
 

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