Matchbox launcher reacts to emergency band radio dispatcher

[Jeff] and his wife put together a firefighter themed birthday celebration for their son. As he’s not entirely handy in the kitchen, [Jeff] decided not to lend a hand with the baking or cake decorating. But he didn’t forego the opportunity to combine a couple of different projects to make a Matchbox car launcher that responds to emergency band radio.

Since he’s an amateur radio enthusiast he already had a scanner to monitor the air waves. Apparently there’s a band just for relaying dispatch messages to emergency vehicles. He set the radio equipment to only monitor that channel. An Arduino was added to the mix, taking measurements of the voltage level on the scanner’s audio output. When it’s driven high enough the Arduino trips the toy car launcher.

The car launcher itself is a pretty nifty setup. There are five chutes at the top of a ramp that each fit a car. A sliding gate holds them in place, but can be removed one slot at a time by a geared motor. The addition of a poster board facade and two flashing red LEDs makes the setup look right at home with the other party decorations.

See a call come into the station in the clip after the break. We don’t have a category called “fun parenting” so “toy hacks” will have to do.


  1. Jordan says:

    OMG that’s where I live! :D

  2. Ashaman99 says:

    That rocks! I love the idea of getting kids interested in hacking by exposing them to these kinds of builds when they are young.

  3. Mr-Midnight says:

    Not knowing what is dispatched usually wouldn’t it be a little confronting for a 4 year old to hear well nasty things.

    “Double homicide on 44th. Hooker and a pimp.”

    Not sure if I would my kid to realize the reality of fireman Joe.

    Great hack nevertheless.

    • Cin says:

      See my response below…

    • Jeff says:

      It did occur to me that there could be the occasional questionable word on the human dispatch channels. That’s why I limited the scanner to only the “Alert” talk groups which consist solely of a computerized voice announcing the nature of the call (“structure fire”, “cardiac”, “breathing difficulties”, etc) and then name the responding units and give the location. Cheers! :)

  4. Chris says:

    Why use a few capacitors and resistors when an Arduino will suffice.

    • Alex Rossie says:

      Lmfao, this is pretty much how most people actually think these days (I’m often guilty myself)

    • Jeff says:

      One day I hope to be proficient enough with analog electronics to make this sort of thing without a microcontroller. Until I finish my copy of Art of Electronics, though, I’m going to keep plugging along with what I have at hand. When the only tool is a hammer… as they say. I’m going to keep using my hammer whenever I can until I have more tools in my toolbox, so to speak :)

    • Stephen says:

      Not everyone can effectively use analog components.

  5. Alex Rossie says:

    This is epic.

  6. Cin says:

    This is my brother’s hack. As a proud sister I just wanted to add for the concerned commenter that there is nothing about it inappropriate for four year olds. The dispatch is on mute except when it recognizes a request for a firetruck. its an elecronic voice that does the dispatching, so there would not be talk of hookers and pimps, or homicides or anything. just “Firetruck needed in zone 10, dispatch immediately to this address.” or some such thing. The post on my brother’s private blog has a video and explains all this in much more detail than this site does. It’s a pretty awesome gadget!!!

  7. Dr. DFTBA says:

    It would be pretty cool if he could hook up a thing where if a police call comes, it drops a police car, if a fire call, a fire truck, etc. It would be hard but cool.

  8. cde says:

    Even if the kid can’t hear it, this is definitely one of the most morbid things on hackaday. Now you can equate the need for firefighters at a burning house with people inside, with FUN :D

    It is a nice project though.

  9. Michael says:

    Oh I want this. Yes I do. But for boats. Yeah, and with lasers!

  10. phil says:

    Good to see some more North Carolinians here! Sweet project, nice solid build of the launcher.

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