Let's Make Robots!

Firefly 1.0

Simulates firefly synchronization

First off all, apologies for the lack of video. This device was made for my brother for his birthday and that was before I became a member of LMR.

It is based on the firefly from this guy http://tinkerlog.com/howto/synchronizing-firefly-how-to/ but instead of buying a kit I decided to have a crack on it myself using PICAXE 08M. It was my first custom made PCB (and not all that good design…).  The PCB was made up of a matrix containing 15 separate units sharing only power. The plan was to cut them out individually and mount them inside ping-pong balls, suspended by thin wires from the ceiling. That didn’t work out since the LDRs was not sensitive enough (I probably should have gone with photo transistors instead) .

Anyway, a fun little project that I will probably revisit when I have learnt some more electronics.

The ‘Fireflies’ start up flashing in sync, but when disturbed by the light from a laser pointer they get all mixed up. Trying to get back in sync can take all from 5 seconds to several minutes.








Mounted with regulator



I printed the PICAXE program on the front just for fun.


PS. When mounted on a wall, the front is completely white

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Yes, that would be an option, although using the LED as input sensor is a bit slow, due to the charging cycle of the LED. And as I tried it out, it was not very accurate and sensitive. But worth a trial, I think.

Hi Geir,

 great that you've ported the fireflies to PICAXE. And really great presentation! I like the combination with the code to show how simple these things are.


One note on the placing of the LED and the sensor.

If you place the LED away from the sensor (not one on top of the other), it might result in synchronization pattern that have a fovoured direction. That is caused by a sensor that "sees" the LED of the south firefly easier, than the LED of the north firefly.

I hope you get what I meant, not that easy to express.

Keep it up!




You are absolutely correct in that the current layout has a favored direction.

After seeing this post http://letsmakerobots.com/node/8442 I started wondering if the LED itself could be used as the sensor.

My electronic skills are limited at best so I probably have to read up on that before my next attempt.  

Wow, those are some neat nerdy aesthetics! Code as decoration. That is original.