LED fireflies prototype

Step 3 Suggestions

so for my second or third test, really my first worth posting.. the results are pretty good..


battery life is hard to estimate on this one, but... during the day the pic will consume ~25-30 microamps of current.. thats... microscopic.. at night, depending on the blink patterns generated.


sparkfun claims their coin cell has 250mAh of battery life, which, if the pic were the only thing on there would last well over a year, with the LEDs and of cours other factors like phantom drain from the battery..

i would estimate a couple weeks of random firefly like goodness..


some other ideas being thrown around are to maybe use infared to communicate between fireflies to some interesting effect.. but let me know what you think!

Comments

[Noblevagrant]

i would like to see an irfra red led that hit tv on off codes as full spectrum as possible. imagine tossing it up high in a bar you dont like. they would think there tvs were haunted.

[JackandJohn]

Uhm.. like this thing?

http://www.tvbgone.com/cfe_tvbg_main.php

Basically just have to mod it a little and put a magnet on it

[btop]

you could get a universal remote and record the signals coming out as it scans for the off signal.

[phar]

i'd do it as a request, but i dont own a tv, and i'm not sure where id get a list of universal "off" code..

im also not sure if *every* tv remote operates at 40khz

another question would be if the "led as a sensor" with an ifared LED (the black ones) would also work as an infared sensor..

i'm still trying to figure out if i can use the RGB led as a color sensor

[teknician89]

Hello Phar, How would you use an LED(even a standard LED) as a light sensor? Is there some current flow through the semi-conductor when light is applied into the lens? I have never heard of using an LED as a light sensor before (only photo-cells or solar cells). I also have done some work with PICs, specifically the bigger 16c628, but I have a 12f675 that is looking for a nice use :). I was thinking that you could use an IR LED and photo-transistor in a PIC program to syncronize the firefly's behaviors. One example might be: have a master firefly send an omni-directional message to other nearby fireflies (via IR communication), who flash their pattern, wait a bit (oh, say 1/10th of a second), and then re-transmit the message to other neighboring fireflies who do the same - resulting in a cool wave effect. You might have to include some logic in the program to keep one firefly from signaling itself or its neighbor more than once in a given time period. Also, I was curious, did you write your own PWM algorithm or are you using the on PIC PWM facilities. I am interested because I wrote my own (havent figured out the on-board PWM yet) and I noticed from the video that your PWM is very fast. My home-made algorithm is fairly slow, even on an 8 MHz clock... Do you have the source code for your PIC? I would be interested in looking at it and maybe making my own :). Thank you much, Tek

[Drew-Oz]

Oh, I just found this instructable too...

http://www.instructables.com/id/Programmable-LED/

same-same, but different

always good to read around a topic

[Drew-Oz]

Hey have you seen this instructable?
http://www.instructables.com/id/Synchronizing-Fireflies/

might help with the synchronizing effect you're looking for...

[phar]

yeah i ended up seeing this after i posted mine (ended up as a "related" instructable)... the only thing is that i think with a bit more code i can do something like this without adding any extra parts, and if there are any more parts, those parts are focused on power usage. unfortunatly work has be a bit busy, my weekend is going to be spent with two servers, and a lanforge satellite simulator, i'll try to get a new version out next week.

[phar]

last things first, all of the code is linked from the instructable c and asm. next up, led as a sensor, i'm not sure who thought of this, but its a clever trick using some of the other principles of electronics.. with the whole "lumped matter dicipline" sometimes you forget that components have other properties.. for example LED's are just tiny solar panels.. or LED's can be tiny capacitors.. with "led as a sensor" your using both of those non-light-making" properties, your timing how long it takes the depletion region of the diode (functionally a tiny capacitor) to disipate when ambiant light is affecting the discharge rate (since the voltage generated by the light creates slight bias on the diode).. once you start thinking about things that way, why cant i do serial communications between two fireflies without adding parts? i can modulate a signal at 40khz just like a remote control..

[Noblevagrant]

well would it be possible to take apart a universal remote to get the codes? especially the "learning" type remotes

[Noblevagrant]

http://www.thinkgeek.com/gadgets/electronic/755e/ maybe something like this.

[darus67]

The TV-B-Gone can also be had in kit form

http://www.ladyada.net/make/tvbgone/

The source code is available free for download.
The codes for a bunch of TV brands are included in the source.

[Doctor What]

you don't own a tv?!!!

[hondagofast]

I'd love to do that! XD