'Sound Graffiti'




About: Open design advocate. Maker of things, collector of comics.

This is a simple electronic gadget you can build for yourself using old electronics and cheap kits. Connect the components, protect them with polyurethane foam and install them in the street. Record a message and let others record their own message.

//// Vox Populi is an open source project based in DIY interaction designs to fight advertisement and corporate branding in our streets.////

Step 1: Connect the Components

This is what you need:
_Voice synthesizer type Cebek ref. C9701 or similar. (Basically a 20seg voice rec+play)
_Speaker (as big as you want, consider 4 cm /1.6inch diameter minimum)
_Infrared sensor (I used CROW ref. SPR-100, but any alarm infrared sensor should work also tiny like cebek ref.7288)
_5V Relay
_Batteries (depending of synthesizer and infrared)

_Polyurethane foam, sold in spray avaliable in any drugsore
_Half plastic bottle

_soldering iron
_Silicone mould (optional)

Step 2: Change Speaker and Rec Button

Usually voice synthesizer are provided with tiny speakers, change the original one and connect a bigger one to obtain louder sound. (I used one as big as my bottle screw top as they have to fit together)

Change also the rec button for a lamp switch to make an easier interaction.
The switch is going to work better if you stick it to a piece of wood or plastic as a lever.

At the end, secure the connections with the gluegun to make sure it's going to work.

Step 3: Change Play Button

Change now the play button for the infrared sensor. That means that the gadget is going to play the recorded message when pedestians walk close to it. That makes a much more interesting interaction that through buttons.

Follow the connections of the original play button and exchange them for the infrared. Remember to use the Relay.

Step 4: Protect

Before putting it al into foam, protect the sensible/mechanic parts to avoid foam disables them. Protect the speaker, microphone, sensor and switch. (follow the sketch)

Step 5: It's Foam Time

Now that the electronics are done make sure they work as planned.

If everything it's ok, then find a silicone mould (any pastry-mould should work) or any other PP / PE packaging (foam is not going to stick to it). You can also work without mould, by putting trhe foam directly on the electronics.

*Foam is not only going to keep things together but to protect them from weather

Wait util the foam is completely dry (also inside) - usually takes from 6 to 12 hours (see foam spray instructions)

Step 6: Battery Location

When the foam is completely dry it's easy to shape simply by cutting it with a blade (cutter).

Step 7: It's Done!

Now do a hundred of them and spread them away!
(stick them to the walls with some more foam)

*depending on the batteries should work for a week at least



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    55 Discussions


    2 years ago

    Intresting idea! I have a feeling you could turn a few heads with this project (and freak a few people out...)! It's a shame that I don't have a recording module and an infrared sensor on hand, otherwise I could throw this one together in a few minutes (excluding the foam, of course; that could take an entire day).


    9 years ago on Step 5

     was wondering instead of using 12 volt battery could a small solor panel work the ones you get from radio shack  and also if u can like add a flash drive that has sounds or music and to be able to put it in a loop


    10 years ago on Step 2

    thats cool as H3ll you should make them to play Death metal and put them outside old folks homes/nursinghomes lol

    1 reply

    Reply 9 years ago on Introduction

    ya my granny almost has a heart attack every time my phone goes off (my ring tone is the sex pistols)


    9 years ago on Introduction

    Any1 heard of Geocaching? Any way, how but using one for a digital logbook in a geocache? the first voice recorder logbook by placing one in a tic tac container and putting one in a cache, LOL.


    10 years ago on Step 7

    what are we lookin at price wise.....


    10 years ago on Introduction

    I thought of this same thing! a built a protype that would play a song when it detects someone pulling it of the wall, but it looked too much like a roadside bomb to put outside:(

    11 replies

    Reply 10 years ago on Introduction

    Eneergcam, you should definitely put that roadside bomb lookin prototype outside. Just picture some swat guys going to pull it off the wall and it starts playin "Its raining men" or something. I think that would be hilarious.


    LOL Yeah kind of like those LED robot looking things in Boston that freaked people out! Including the bomb squad!


    Reply 10 years ago on Introduction

    that 'robot looking thing' was a mooninite! But don't worry about it. Nobody in Boston knew what it was either.


    Reply 10 years ago on Introduction

    You're gonna have to make your own now. They were selling on Ebay for thousands of dollars (genuine Adult Swim "bombs"). I felt like such a numbskull for not actually leaving my house that week and grabbing one of my own, what with living in Boston and all.


    Reply 10 years ago on Introduction

    HAHAHAHAHAHAHAHAH, YES DO IT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! make sure there's a video camera somewhere though :D


    Reply 10 years ago on Introduction

    Yeah, it's a shame that people these days would freak out and immediately jump to the worst case scenario like that. I'd hate to build one and stick it on a wall, only to have the bomb squad called in and blow it to pieces!


    Reply 10 years ago on Introduction

    hey, where do you live? I made the instalation in the middle of barcelona and the feedback of pedestrians was great. I guess the aestethics of the object looks innocent enough... I've seen similar actions in Berlin and they work great too.


    Reply 10 years ago on Introduction

    I live in Canada. I'm certain that pedestrians would love it here too, but all it takes is one meddling person to call the cops and then the fun is over. It's a shame that we're so reactive over here.