[dev_dsp] wanted to try his hand at creating a purely analog implementation of multiple synchronizing fireflies powered by a single battery and built from off-the shelf, through-hole components on inexpensive protoboard. In theory, even your local Radio Shack should still carry all of this stuff. He was obviously inspired by [alex]‘s fireflies that we’ve covered in the past, but he wanted to see how far it could be taken without the use of a microprocessor.

In the end, [dev_dsp] relied on one crucial piece of digital ware, the ever-popular 555 timer IC, but he’s using analog discrete components to do the grunt work of adjusting the phase of each firefly by feeding a little extra current to the trigger capacitor whenever the flash of a nearby firefly is detected. After the jump, you’ll find schematics and a video demo of three ASync-Firefly modules in various stages of assembly playing with one another while [dev_dsp] discusses their operation.


  1. jeremiah says:

    I don’t see a video after the jump… not trying to nitpick, I just wanna see it. :)

  2. HARaaM says:

    Link server overload, The video is great !

  3. Adrian says:

    A 555 is digital now?

  4. devdsp says:

    Adrian: The 555 has an SR latch in it which technically makes it at least partially digital, so I can’t claim that the whole thing is analog, just the synchronising part.

  5. catzburg says:

    Yeah I know eh? A 555 is definatly analog electronics. Just because it tends to have a discrete response doesn’t make it digital.

  6. Phil says:

    I wonder if this could have been done all-analog with a ujt instead of the 555.

  7. collin says:

    Just an aside… This was a project in Scientific American’s Amature Scientist column back 15ish years ago. You don’t see a lot of love for that column on hack/make sites. I’m not that old, but if you look at the projects from the 60s/70s there’s some amazing stuff: CO2 laser, NMR, electro staticparticle accelerator…

  8. steve says:

    The 555 isnt really a digital chip… yeah it outputs square waves but that doesnt make it “digital.” its a completely analog circuit inside

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