A hotel manager asked me if I can find a suitable LED to mimic firefly in the hotel garden. He wants it to be as realistic as possible. Weird request but very interesting! Finding/programming a driver with random natural blinking is another challenge.
We can place several fireflies in a small light bulb diffuser in front of the sensor. But I donāt know how Maukka would get those creatures in Finland.
- Clemence
I found this article from 1964
Wow Djozz, very informative document you got there! Big thanks. Iāll try to find the suitable LEDs for it. Different species different spectral distributions too. 500nm - 700nm seems to be the range. But the peaks are species dependant. Now Iām thinking to lure firefliesā¦ā¦
- Clemence
It looks like a phosfor converted green has about correct width of the emission peak but has the wrong peak wavelength (520nm for the new E21A converted green). The Rebel PC-lime however has its peak at 545nm which comes close to some of the firefly species tested in the 1964 article.
PC limeā¦ interestingā¦.
Letās see if the next E17A green samples I will be receiving looks good. Want some Djozz? 
- Clemence
Of course Iād love some. Brand new leds, hmmmm :heart_eyes:
A quickndirty spectrum of my flaslight with Rebel PC-lime:
This should be enough to satisfy human eyes. Nobody would see the difference. Where did you get that PC Lime Djozz?
I will send some Red Green Blue Amber E17As to you when I get them.
- Clemence
Not sure where best get the Rebel lime at the moment, I got them years ago from a portugese aquarium seller that has disappeared since. I see Ledsupply, Luxeonstar and Digikey, so all american sources. There is a Luxeon Z with the same colour as well at Digikey.
Btw, I have quite a stash (30 or so, would have to count them) of 20mm Rebel Sinkpads doing nothing, got them free from vestureofblood a few years ago. I could send them if they are suitable for your project (those Rebel lime leds put out up to 1000 lumen if needed :sunglasses: )
I see that RS-online has the Luxeon Z lime (Luxeon Z has a simple two-pad footprint, like the E21A) for more than $5 a piece, a pretty expensive led but I could order there and send them.
Thanks for the offer Djozz but letās wait, until I get those Green E17A first. If theyāre good enough then I donāt need the PC lime. Besides E17A form factor is better suited than the bigger lumileds. I think green E17A inside a yellow plastic cap (or yellow heat shrink tube) would look very close to the green-yellow firefly light to the eyes. I just noticed that my Armytekās green switch LED looks somewhat PC lime behind itās yellow silicone button.
- Clemence
The Luxeon Z is tiny, hardly larger than its 1x1mm die. And what I remember from European fireflies the 530nm greens do not match that colour.
(Lampyrus noctiluca: )
(being persistent here 
)
How did you install those Luxeon Z on it? Did you ask it to carry the battery pack too?
Anyway, I just checked one of your test that I never seen before. OMD, this thing is just too small. But yes, the colour spectrum is very close to firefly.
- Clemence
Maybe you could catch the fireflies with Optisolis. Fired up the 5000 K quad at 4x100 mA without optics and it only took a minute after a fly started investigating it. Landed right on an emitter and made it its home until I turned it offā¦
To be honest, I have no idea if a single firefly would have enough output for measuring.
It has a hydrogen fuel cell, didnāt you notice the small hydrogen cilinder between the legs?
Ages ago I took a 555 timer and fudged about a 5-10sec period and fractional-second āonā-time, and used a 3V yellow Christmas light bulb as a firefly lure. Kindasorta worked. A bunch would flit around the yard but nobody would get too close to investigate.
They probably figured there was something hinky, and didnāt want to get too close.
Kidding Djozz. I know about the natural fuel it carries. Itās just your firefly is much greener than ours. Hereās itās closer to green-yellow.
- Clemence
It could be your timing was spot on to their sex signal. Thereās a very good documentary movie about it by the legendary Sir David Attenborough: āLights On Earthā. Watch it for free in YouTube. Firefly also one tricky creature which can fool other male to get the female by sending false beacon.
- Clemence
From what I understood, the āfittestā males were those who could stay lit the longest, like who could hold a note the longest. The females would be attracted to the long-lighters, and the would-be bugs would go without.
So I set it for something like Ā¾sec or so.
At some point, I wanted to mod it and ended up cooking the 555. Still got it somewhere, but it doesnāt work. Just a āratās nestā thing, bend the pins from the 555 straight-out, solder the resistors and cap right to the pins.
Toykeeper has in her AndĆŗril Firmware random modes: Thunderstorm and candle light.
Maybe you can tinker with the values?
Letās wait until the project gets real. Oftentimes, the clients asked me their impulsive wants. Toykeeper and Loneoceans are two names I have in mind, both of them have this ārandomā mode driver.
- Clemence