Microcontroller-powered Missile Launch Controller

[Josef Jahn] has posted a detailed guide on building a microcontroller-based launch box. Constructed from an Atmel ATMega168 and powered by a 12V rechargable lead gel battery, the launch box is fully portable and includes a number of safety features. Going the extra mile on what could essentially be a simple push button launcher, he added three safety switches, a sixty second after-launch timer and a beautiful (not to mention rare) PLED display complete with dramatic status messages. Check out a video of the launcher in action after the break.


37 thoughts on “Microcontroller-powered Missile Launch Controller

  1. It would be 9001x cooler if a key was required to unlock the button to launch. Or if there was a glass cover was on the button that had to be unlocked with a key or broken with a small device of persuasion to launch.

    Just an idea.

  2. This needs to be hooked up to my power switch.
    Then, after initiation, a voice that sounds like a female talking into an intercom will count down, and a whirring noise will become ever louder as the timer gets closer.

    The lights will dim a little, there will be a loud noise, and then the computer whirrs to life.

    That’s what needs to happen, every time…

  3. @_matt

    What? Knoppix’s “Intiating startup sequence” isn’t good enough for you?

    Hahaha…it blasted through my earbuds at my soundcard’s maximum volume…my roommates got a laugh out of that!

  4. You should put the switches in a different order just to make it a little trickier to get the right sequence. other than that it looks like a lot a fun. it would ammuse me for about an hour and a half.

  5. I feel like such a nerd. The beauty of this project made my knees a bit wobbly. I’m totally going to wire up my jeep with something like this. I’ll likely use a keyswitch instead of button, though.

  6. @jbot
    I don’t know what Knoppix’s startup sound is, so I’m downloading a live cd.

    Does it sound like it should belong with this project?

    I always wish my computer had a really beefy power switch, and sounded like a jet engine spinning up…

  7. All those switches, that have to be turned on in the right sequence and everything, and a single faulty transistor, relay, of little software bug could still cause a lot of trouble.

    IMHO, this is just a gadget, nothing more, because the circuit that actually switches the output isn’t designed properly. You should at least have 2 relays wired in series, and build in protection for sticky relay contacts.

    There is even a chance of the circuit closing if you drop the thing in just the right way, because of the single mechanical relay.

    Nicely done, but that part of the circuit needs some attention if you really want to do it properly.

  8. @Sparky: There’s a very simple and foolproof way of ensuring that neither a sticky relay contact nor any software problem can cause a premature launch:

    Switch 1 removes all power from the device. It is a safety switch that you will have a hard time toggling by accident – and even if you can do that, you still have to have a software failure and/or a problem with the relay *at the same time*.

    So really, I see no problem there. Of course you could use a second port of the controller to switch a second relay. But the most important safety feature is the ability to physically remove power and thus override any individual software or relay problem.

    As it is now, you should only enable switch 1 if you are ready to launch, just as you disable the safety of a gun only when you’re about to fire.

  9. Rare PLED display? Huh?

    I can buy them from several places. how the hell is something that is readily available rare?

    I have some rare ardunio kits I’d like to sell for top dollar!

  10. @fartface:

    Quote from http://www.osddisplays.com/pled.php

    “Recently several of the world’s largest PLED panel manufacturers have announced their withdrawal from PLED production because of financial reasons. The withdrawal of these suppliers will have a direct effect on the availability of critical components that sustain OSD’s PLED module production.”

    Quote from http://www.lcdforums.com/forums/viewtopic.php?p=17963

    “Due to our PLED (Polymeric Light Emitting Diode) supplier announcing that they are no longer going
    to be manufacturing this technology, we, Matrix Orbital, hereby submit this letter to inform you that we
    must discontinue all of our products that use PLED technology.

    Please note that PLED technology will be discontinued throughout the entire industry. It does not only
    affect Matrix Orbital.”

    If you have any links to places where I can get monochrome PLED (not OLED) character and/or graphical displays, please do post them!

  11. This is kindof cute. I think if I were to build something like this I’d have added a keypad to enter a password (PIN), and a microphone to check the voice print.

    Keys as mentioned above are a great idea, but like modern cars, don’t forget to add some kind of passive RFID system (different from the one from TI that was cracked a few years ago).

    And one more thing – a local destruct mechanism to punish those who misuse the device. Poison gas, perhaps; we don’t want to harm the device.

  12. excellent looking interface! I can integrate this into a project i have now.

    Could you possibly add some extra info?
    – post the software
    – list the sources/part #s for the switches, covers, and button
    – what were the considerations in picking the PLED? Was it easy to use?

    Harnessing the power of the internet, does any other reader have a reliable source for PLED displays? Do they all take a lot of power? I need a day-time readable output.

    Thanks for the great write-up. Slick project!

  13. I agree in part with sparky. If you dropped the device the relay may (although nearly impossible) trigger. However this could easily be overcome by using Solid State Relays.

    I know this would never happen but i was just wondering, is there any safety device in place in case the device did develop a fault? I mean if for example water got in the unit and shorted the relay contacts making it activate?

  14. @joer: As I said above, the first main switch removes all power. You can drop it as much as you like, you can short-circuit the relay, as long as you don’t switch on the first safety switch nothing will happen.

    For the box to launch prematurely, you have to have TWO failing components: The relay AND the first safety switch. So there’s no single point of failure.

    Also, I think you guys should keep things in perspective: This box is meant for model rockets. What if water gets into your “Estes” ignition trigger and shorts the contacts? What if you drop that “Aerotech” launch box, it falls apart (which it does quite easily) and the right pieces of metal come together? There’s definitely an end to what you can prevent. The idea is to not have a single point of failure, i.e. don’t rely solely on a relay, don’t rely entirely on software, always require at least two different actions to be taken for a launch to happen (i.e. not just one single pushbutton)

  15. To make this project a little more interesting I would add a keypad, to enter in launch codes of course. I think I missed something about the output of the box, what type of signal is required to launch the rocket?

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