Brian writes in…

Recently, I wanted to network my media center in the living room of my apartment. I was not satisfied with running an ethernet cable down the hallway and putting holes in the wall was not an option. Thats when I thought of running the cable through the air duct, my 555 based light-seeking robot came to the rescue!

Make Pt0538
The Biggest Little Chip – An introduction to the versatile 555 timer.

 Folded Timer555-1
Tons of 555 timer projects!

  • 00t8r


  • A Peterson

    That is, of course, plenum-rated cable?
    Safety first, y’all.

  • dave

    Actually running cable through air ducts or over raised ceilings without proper support is nearly always against the fire code. Not that it necessarily matters for your home, but something to keep in mind.

  • Pavel Ushakov

    Very nice!

  • Fishtape

    I guess a fish tape was just out of the question… no?

  • The Thompson Five

    Awesome! You should mod it to clean the duct before you get Legionnaires disease.

  • BrianP

    Thanks for the feedback guys! I know that heat should be of concern when running cables and I definitely think that anyone doing this should make sure that it is safe. In this case, the heater produces its air by running air through a hot water radiator. This will never get hot enough to melt or damage the cabling.

  • Microman171

    What music is this? I see it on lots of things and I really want to know where you get it.



  • The Samurai

    very limited… but if you had the circuitry built for this already, then it was definitely worth it for the application. great stuff.

  • vivi

    I like the simplicity. Why people keep building things in Altoids tins however, in particular involving electricity, I cannot understand :P

  • Artie

    hey dude..just wanna ask, where did you put the potentiometer in the circuit and what is its value?

  • Steven

    I would like to know the resistance of the LDR please.

  • selva

    can u tell me what type of LDR resistance u had used in ur circuit diagram..