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Hackable Microcontroller-Powered Valentine's Card 133

compumike writes "If you have a significant other to impress this Valentine's Day, consider putting your programming skills to use. This video tutorial shows how to build an LED Heart Valentine's card, powered by a microcontroller running C code, with a neat randomized 'twinkling' effect in an interrupt handler. Think about it: how many ladies can say that their Valentine's card runs at 14 MHz?"
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Hackable Microcontroller-Powered Valentine's Card

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  • by Arthur Grumbine ( 1086397 ) * on Tuesday February 10, 2009 @12:26AM (#26793549) Journal
    Him: Yeah, babe, and now you can tell your friends that your Valentine's Day card runs at 14 MHz.
    Her: Really?! 14? How many songs does that mean it can hold?

    Him: Yeah, babe, and now you can tell your friends that your Valentine's Day card runs at 14 MHz.
    Her: ...uh, yeah... I'll be doing that right away...

    Him: Yeah, babe, and now you can tell your friends that your Valentine's Day card runs at 14 MHz.
    Her: ...
    (She remains as silent as all other RealDolls)
  • the "hearthack" tag
  • Yes... (Score:1, Funny)

    by Anonymous Coward
    but can it run Ninnle Linux?
  • I'm a huge geek. I always read up on new hardware/software. I play MMOs, I have a tech related job.

    And this is too geeky even for ME.
    • well, yeah.... and, who the hell would you give it to?
    • Re:Come now (Score:5, Funny)

      by iocat ( 572367 ) on Tuesday February 10, 2009 @01:25AM (#26793915) Homepage Journal
      It's not too geeky, it's too PATHETIC. If you need a microcontroller running at 14Mhz and C code to blink some heart shaped LEDs, you should just turn in nerd card now. It's like using an anvil to hammer a picture hanging nail.

      If you can't create that card with a 555 and a couple resistors, I wouldn't be surprised to see your Valentine laugh in your face and go off with a real He-Man who writes assembly.

      Christ! A 14Mhz microcontroller... if you're gonna use that, the damn card better access the internet or play NES games at least.

      • Re:Come now (Score:5, Insightful)

        by daveime ( 1253762 ) on Tuesday February 10, 2009 @05:53AM (#26795059)

        Damn, you mentioning 555's takes me back ... in 1981 when I was just 13 years old, I got a little project published in Everyday Electronics, on just such a premise ... an oscillator made from two gates of a 4001 feeding into a 1 of 6 counter (4022 ?) and 6 LEDs cycling in sequence. I'd abandoned the 555 in favour of the NOR gates as it was bloody unstable and used to do horrible things to the power supply.

        I got paid 12 pounds for getting that published, which was like a kings ransom for a 13 year old.

        Microcontroller pfft ... can you say overkill ?

        • by CompMD ( 522020 )

          Microcontroller? Really?

          I think that using a counter with some 74 series logic and LEDs would be cool, and it would actually be appropriate to drive them with a monostable multivibrator for this project. :)

      • Re: (Score:2, Funny)

        by f0rk ( 1328921 )

        It's like using an anvil to hammer a picture hanging nail.

        I don't get it...

  • pfftt... (Score:5, Insightful)

    by djupedal ( 584558 ) on Tuesday February 10, 2009 @12:45AM (#26793691)

    >" many ladies can say that their Valentine's card runs at 14 MHz?"

    How many want to?

    • Well, per the website, "The holes are just the right size to squeeze the LEDs through and give a good friction fit." Maybe that line will be more appealing; I guess it depends on the lady.
    • And remember - investing in MS is risking having your own money used against you in the marketplace.

  • Invalid XHTML (Score:4, Interesting)

    by XanC ( 644172 ) on Tuesday February 10, 2009 @12:53AM (#26793735)

    That's the least page I can remember bearing a "Valid XHTML" logo at the bottom. Ugh.

  • Chocolate (Score:2, Funny)

    by Joebert ( 946227 )
    I'm fairly sure they're going to be pretty pissed when they open it expecting chocolates and all they find is a bunch of wiring and batteries.

    I don't have a girlfriend so I can't be entirely sure, but I do know that the chick at the video store wasn't happy when I finally got her to open the box of chocolates I was holding in front of me only to find my penis poking in from a hole in the bottom.
  • by canatech ( 982314 ) on Tuesday February 10, 2009 @01:02AM (#26793793)

    I bet with liquid cooling you could get it to 18MHz!

  • Only a really 'special' girl is going to be impressed by this. The only thing a girl wants you to make for Valentines day is a dinner reservation.
    • While there's nothing wrong with a dinner reservation at a nice restaurant (who doesn't like good food?), my own experience suggests that a sincere creative gesture is often pretty well-received.

    • Re: (Score:1, Insightful)

      by Anonymous Coward

      And that attitude is why you can't get laid. Or maybe you just go for really shallow women so it has skewed your perception of the entire gender.

      And yes, I'm female. Really.

      No, really.

      • Is that why your posting as AC?
      • by pla ( 258480 ) on Tuesday February 10, 2009 @08:49AM (#26796005) Journal
        And yes, I'm female. Really.

        No offense, but what "real" females - shallow or not - say and what they mean differ drastically. I don't think this involves lying so much as simple self-delusion (since they seem to actually believe what they say), but it all ends up the same.

        Simple example - Would you rather get a blinking card that represents a week's work from your SO, or a mere half-day's pay worth of roses delivered conspicuously to your workplace?

        And before you answer, I've tried both (well, not a blinking card, but same idea). The "lovingly crafted with my own hands and dozens of hours of hard work" gift gets a "gee, thanks, how... nice". The large bundle of dying plant debris result in a tigress throwing you to the floor and a few hours of scratch-mark-leaving entertainment.

        Women want stuff and attention, and as much of it as possible. They don't care about the effort or intent involved, just the end product.
        • What was it that you hand crafted for her? If you spend 99 hours on an electronics project that flashes her name and is controllable via serial/USB and it's not something she likes, I can bet she'll disregard it completely REGARDLESS of how much effort you tell her you put into making it.

          You could save your money, time, and headache(s) by getting her a nice card and making reservations at her favorite restaurant, or even cooking her favorite meal right at home, and get the "throwing you to the floor" result

        • Re: (Score:2, Funny)

          no, don't mod this Informative. This is bunk. Not all of us girls want stuff (well, I admit, there IS a lot of girls who do). But there are quite a few of us too, who want 'effort'. There's a difference. And I for one, like the blinking card. Finding it was coded by my sweetie would induce lots of lusty ideas. Any idiot can make reservations.
        • Actually, I think it depends on the woman. My wife is all about thoughtful gifts. If I spent the time to make something for her, she loves it...although it certainly helps to make something she likes. For example, a bad idea would be...hmm...a hackable microcontroller-powered valentine's card.
    • Re: (Score:1, Insightful)

      by Anonymous Coward
      Look, a dinner reservation on Valentines is an appalling night out. The restaurant is trying to squeeze in two extra covers, the kitchen is overworked, it's just a crap night to eat out. Now, if you were to learn to cook something other than ramen and invite her over for a serious dinner followed by a night out dancing/drinking whatever you know she enjoys. You'd make a better impression than some Hallmark fool with his dozen roses @ $10 each and an expensive reservation for a shit meal. just sayin'
    • Only a really 'special' girl is going to be impressed by this. The only thing a girl wants you to make for Valentines day is a dinner reservation.

      Meh, I'd rather cook... I'm pretty good at it. Of course, I could go out to dinner so I could see if there's something new I could learn to make. I would rather receive something from my SO that's from him, though. You know, either something that's what he does or something that he put thought into... something that shows that he pays attention to me. Of course, when I do gifts, I make them but I'm into a lot of arts/crafts. The last gift I made was a sterling silver and peacock blue enamelled copper b

  • Should make for an interesting week!
  • I saw tons of "record your own love song" card at Hallmark. I kept wondering if it would be possible to hack the card after the envelope been sealed to change the recording to the Barney theme song ("I love you, you love me..."). Should get some special guys dumped in a hurry to make some special girls available. Anyway, just an idea...
  • Hackable Mind Control-Powered Valentine's Card

    That would be so much cooler, and helpful for this crowd.
  • by hack slash ( 1064002 ) on Tuesday February 10, 2009 @01:48AM (#26794047)
    If you want to make a special card which lights up, I saw this great little project close to christmas and so I made 9 cards, but instead of watch batteries that would die after a week or so I wired in resistors & USB plugs (strangely the only place I can find solderable USB plugs online/offline is from Maplins []!), all the recipients loved them and most wondered how the blinking flip they were lit up.

    Edge lit holiday cards [] (the snowflake one looks much better with a black background & two blue LEDs, one at the top & other at the bottom)

    Next christmas I'm going to have to make something even better - anyone have any simple circuit designs on using an LED as a light sensor and then making some more LEDs react by blinking?
    • (strangely the only place I can find solderable USB plugs online/offline is from Maplins!)

      They are *weird* like that. The amount of odd stuff you find in Maplins is incredible, as is the number of things you *don't* find that are perfectly ordinary. Reverse SMA plugs? Masses. Solderable USB connectors? Yup, do you want A, B, mini-A, mini-B or micro? Oh, and what colour boot do you want? 100 ohm 1W resistors? Nope. 50-ohm BNC plugs? Uhhhm, I'll need to check through the back. RG58 coax? Only 3m

    • by evanbd ( 210358 )

      As usual, Digikey [] has them as well -- and a vastly superior web site. You can search on USB cables and select connector to raw cable, or I'm guessing you're looking for part number Q363-ND. (If you're actually looking for PC-mount sockets or something, they have those too...)

      I'll give the LED as light sensor some thought, but I imagine you'd just wire it as a photodiode (it should act like any other photodiode, though less efficiently) with an op amp, possibly log scale it to get good response across ambi

    • Maybe you can use a project I published recently: []
    • anyone have any simple circuit designs on using an LED as a light sensor

      No, I don't think that is going to work. You need a phototransistor or photodiode. Years ago I built a little circuit around a chip which detects changes in light intensity. It is intended for use in an alarm. You might still be able to find this device.

      and then making some more LEDs react by blinking?

      That part is pretty easy. Maybe think in terms of passing the output of a photodiode into a comparator to give a nice 1/0 output and using that signal to control the reset on a binary counter. Then feed the outputs from the counter into the LEDs.

  • She might attempt to do something similar for next month's "guy" version of Valentine's Day. []

    Then again, that might work out well.

  • nerdkits (Score:3, Interesting)

    by LS ( 57954 ) on Tuesday February 10, 2009 @02:02AM (#26794105) Homepage

    these guys seem to have a decent piece of the slashvertisement market recently...

  • I thought it was sweet. I would rather have creative and heart felt than generic, well sans the cheesy Al Green song.
  • This is the second time I've seen an advertisement for nerdkits on the /. front page. The fact is, you can't build any of their submissions unless you shell out $80 or so (I'd double check, but don't want to send them the traffic again) for their 'starter' kit with the necessary components. The videos simply show you how to make certain things above and beyond the projects initially included with their kit.
    • I own a NerdKit and have been having a lot of fun playing with it. While the components certainly cost a lot less than $80, the documentation and real human-based tech support (right down to helping you debug your own code at no charge) is well worth it.

      It should also be noted that if you choose to make more of the kits by buying components, the NerdKits people supply their bootloader and assistance for installing it on a fresh microcontroller. I think it's a pretty sweet deal, even if perhaps a Slashvert

    • Re: (Score:3, Insightful)

      by gunnk ( 463227 )
      All things considered... $80 is not a bad price.

      The kits are for people that are interested in getting started with microcontroller-based projects. Do you remember just how hard it can be to figure out where to start?

      Well-documented projects, all the components you need, support -- for $80 that sounds like a steal!

      Yes, you can get the parts much cheaper, but this isn't about buying the parts.

      If you really do want something a little cheaper you can get started with an Arduino board and browse the various gu
  • Make your date memorable as in live to tell another day, by not putting garments over halogen lamps. I know is just a prop but props can be set ablaze. Just ask Michael Jackson. Cool Valentine's card thought.

  • Instead of wasting your time hacking microcontrollers, why not try something REALLY radical, like, say, a nice dinner out, see a show or go to a comedy club, and maybe a nice little present that she actually wants? Anyone? Bueller?
    Seriously, guys. Maybe do this as an extra little kicker, because let's face it, she HAS to appreciate your nerdiness/geekiness or she wouldn't be with you, but make it your LOWEST priority project.
  • Real Men (Score:2, Funny)

    by zude ( 1249292 )

    A) Real men don't build a circuit with an 14Mhz ATmega, when a couple of 555's [] and a few TTL counters would have sufficed.

    B) Real men don't program micro-controllers in C (or, god forbid, BASIC), when a hundred or so assembly instructions would have sufficed.

    C) Real men don't give their wives goofy hand-made electronic crap on Valentine's Day, because they know their wives will figuratively and possibly literally beat the shit out of them thus belying that whole 'real man' thing.

  • I think she'd have more fun with a Rabbit running at 14 Hz.
  • If anyone has a girlfriend/wife that understands what megahertz are, and would actually be impressed with a card that's measured in megahertz, for the love of God hold on to've found yourself a keeper.
  • by Big Hairy Ian ( 1155547 ) on Tuesday February 10, 2009 @08:13AM (#26795785)

    Personaly I'm sure she'd want something that ran at 150hz (approx)


  • Talk about a waste of cycles. I'm sure the same thing could be achieved with just 1.4kHz.

  • by gillbates ( 106458 ) on Tuesday February 10, 2009 @10:09AM (#26796739) Homepage Journal

    You can get the sequential LEDs pattern with a simple shift register (74HC574 can be wired for this) and a 555 timer. If you want to add randomness, you can add a few xor gates (74HC86) to make a linear feedback shift register. So far, that's less than a dollar of IC's, and no programming required.

  • I've done this! (Score:3, Insightful)

    by fliptout ( 9217 ) on Tuesday February 10, 2009 @11:24AM (#26797667) Homepage

    Three times. I did not exactly make a card- two times I made a board with a PIC and a 2*16 LCD, the third time I simply coopted a spare Renesas dev board. All I did was display some message on the LCD. And the girls LOVED it. You can never discount how much the girls will love something you take the time to make- girls do dig the geeky stuff.

  • The woman who would appreciate this card very well may say the following... Why this card is automatic...It's systematic...It's hydromatic...Why it's Creased lightning (Creased lightning)
  • Strange as it seems, my wife says she still prefers diamonds to a microprocessor-controlled Valentine's Day card... yeah, I know, I don't understand it either!
    • The programming skill of a grown man...
    • The electronic skill of a teenager...
    • The cardboard-cutting skill of kindergarten

    Hmmmm, I'm wondering: will she find this cute, or plain too much geeky ?!?

  • At first I thought it said "Mindcontroller" rather than "Microcontroller" in the title... Dangit, I thought that'd make Valentine's Day easy this year...

Happiness is twin floppies.