Let's Make Robots!

Megan40 - Picaxe 08 Firefly

Attracts FireFlies into your garden

This is robotic Firefly based on a picaxe 08 using UltraViolet leds as sensors.

Flight School.

Here you can see her Big Flattering Stereo eyes, they are simply UltraViolet LEDs - the red leds on top are feedback indicators.

The UV leds are connected to a LM324 opamp that amplifies and also conditions the logic and trip levels going into the picaxe.

I can highly recommend the use of Ultra Violet leds as detectors as they are not affected by ambient /infrared and laser light.

Her rear is composed of a Spiraled Glow PolyMorph tube - it is illuminated by two UV leds.

Flashing good time was had by all......

The little 8 pin chip is its tiny picaxe 08 brain....... inclusive 128 byte memory.

Flashing routines and UV tracking routines fitted noproblemo (the faster you write your code the more you can fit in).

Here you can see her 40MΩ (in total) opamp feedback resistors - although 230MΩ was recommended (yikkeess Air-Gap has less).

Megan40 is attached to the top of a glass jar via a spring to a servo, this gives her life and enables her to track & follow my UV pen light or UV laser. She is sitting on my window-sill enjoying the sun - but eagerly awaits a tickling from my UV probe.......

Yes she is green powered by 2 solarcells float - trickle charging 4 AA recharge batteries

What is Megan40s future :-

I plan to use her eyes as an input program select , ie on "start up" by shining the UV into here right eye...she will go into tracking mode. Or if left eye is chosen then she will go into autonomous mode and act like a firefly attracting real fireflies intomy garden.

NB. UVA-UVB-UVC are all to be treated with care. High level/Overexposure is hazardous to health.

Or if two eyes are chosen ............ who knows..... what would you expect her to do .....?

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Slight correction.

According to http://talkingelectronics.com/projects/StartHere12F629/StartHere12F629-P1.html

"The PIC12F629 does not have analogue inputs - the PIC12F675 has 4 analogue inputs"

In another spot on that page, it also says there are Quantity=4  Type=ADC10 inputs on the PIC12F675

The Rev-ed page says the 08M has 0-3 ADC and clocks at 8MHz.   0 to 3 is four total   0, 1, 2, & 3


it was 6am or so, still up from the day before. I may have been off by a number or so. :) And, the 1-bit adc was a joke. I hope that it was taken as such.

Thanks for keeping me honest Dan.

Well, I did label it a *slight* correction.

You said, "if left eye is chosen then she will go into autonomous mode and act like a firefly attracting real fireflies intomy garden."

Does any flashing or flickering light attract fireflies?  I would think it would need to be the same color as a real one to fool them.


I am edging my bets on UV - (its a longshot - fun project) - however i reckon i will attract the whole insect neighbourhood at the same time.


"Among the most spectacular firefly displays is "The Light Show"  This display consists of thousands of flying males which flash in discontinuous synchrony with each male producing flash trains containing 4-8 flashes given at 0.5 second intervals followed by 6-9 seconds of dark, both time intervals being temperature dependent. Beginning 37-43 min after sunset (Lloyd 1966), on peak nights thousands of males flash in unison and then go dark in unison, signalling together for up to 3 h."


NB. I think fireflies would have a little more than 128 bytes memory and would not be fooled easily ;-)

The most important thing is frequency. Each species of bug that comunicates via light signals has it's own frequency/signal that it flashes.

Cool. I did not know that.

Thanks for sharing Gareth.


This is some might impressive stuff.

Your polymorph work always impresses.