Micro controlled LS LED from Speleogroup

[Burnt_Retinas]

I stumbled across this site and thought their microcontrolled LS LED project was very interesting and thought others may be interested.

http://www.speleogroup.org/

Check out the u controlled one - it looks interesting. May even be suitable for a biking light.

Chris

 

[Tomas]

Nicely done mod on that micro-controlled headlamp. Variable output from a Luxeon, and quite decent efficiency! The biggest thing on their board is the output connector. /ubbthreads/images/graemlins/grin.gif

 

[highlandsun]

Very cool. Those SMT boards are nuts though, who solders that stuff?

 

[koala]

Atmel tiny15 uses 2.7volts, tiny12v goes down to 1.8volts which is much suitable imho. If you don't need the PWM. I am pretty sure you can code the tiny12v to do PWM.

Vince.

 

[PaulW]

Gosh, don't the circuit workings sound a little like the yet-to-be-introduced Arc LS4?

 

[Tomas]

I wasn't going to mention that, but, uh, yes. /ubbthreads/images/graemlins/grin.gif

The Arc LS4 is a much more complex control sequence, though, and all done with just the one membrane switch.

Just similar then, not really at all the same, as the Arc will do more than just step up and down in brightness.

 

[PaulW]

Oh yes. The LS4 will be the answer to a lot of needs. /ubbthreads/images/graemlins/smile.gif

 

[Jonathan]

The Speleogroup circuit is also quite similar to one suggested by 'BikeNomad', using the ATTiny15 as the core controller for a switching converter. Ahh, yes:
Smart LS current regulator

Gosh, that was more than 16 months ago. It is good to see that someone has the attiny based circuits working....

Anyhow, the _great_ thing about using such a circuit in the ARC LS-4 is that not only do we get more lamp features, but there is more 'protect-able ' intellectual property.

Since the general circuit concept is out there, _anyone_ could build an LED regulator using the general circuit layout, and ARC couldn't do anything about it. Note: if someone copied the _exact_ circuit layout, then ARC could get them for _copyright_ infringement, but any serious competitor would design their own circuit board and get around this.

But in a microcontroller based circuit, the actual code in the microcontroller is also protected by copyright, meaning that anyone who wanted to copy the ARC LS-4 would need to develop quite a bit on their own, making it a 'fair' competition.

Thanks for finding this circuit; I've been considering just such a circuit for my own bike lighting applications, and I did a PCB layout, but never got around to building one...someone else's success is added incentive since it makes the project more likely to work. I recently discovered a flaw in the library that I used for the PCB layout, so I know that the PCB won't work, but....

-Jon

 

[koala]

Jon, it's also possible to 'copy(decode)' or get around the copy protection of the firmware in a microchip. Best way to protect work is to rub off all markings on the components, paint all components black, cover them up with epoxy. Make multi-layer circuit board, no printings on circuit board. You will be safe that way. /ubbthreads/images/graemlins/grin.gif.

Vince.

 

[Tomas]

Security by obscurity isn't. (Basic maxim.) /ubbthreads/images/graemlins/grin.gif

 

[Gransee]

It's usually not practical to pay for perfect security but nor is always practical to crack good security.

The advantage to code is not so much that is harder to crack. The advantage is that it is easier to copyright and easier to detect in infringing products.

With good protection, the consumer wins more often. Those who innovate are rewarded- which encourages more innovation. Knock-offs and those who support them break the natural cycle of innovation.

One problem to watch for though is when a company patents and idea but then sits on it and doesn't fully exploit it. For example, you could patent a tube. There are a lot of things you could put in a tube. But if all you do with that tube is make a boring incandescent, then you are stifling all the competition that has a better use for the tube. Each case takes close scrutiny to see what is best for continued innovation.

Peter

 

[Wylie]

Okay all this is great but what is 15 lumen really going to do for you in a cave?

 

[Blue_Shift]

As an emergency light, 15 lumens would be ok. For general use, it would suck. /ubbthreads/images/graemlins/icon15.gif

 

[Doug S]

[ QUOTE ]
Wylie said:
Okay all this is great but what is 15 lumen really going to do for you in a cave?

[/ QUOTE ]

I have been caving for close to 40 years. I have always been interested in lighting and pay attention to what other people are using for lights. I would estimate that the median output for the primary light is actually a bit under 15 lumens. I personally don't find that level satisfactory for a primary light and I am in the "more light is better" camp.

 

[Entropy]

[ QUOTE ]
Jonathan said:

Since the general circuit concept is out there, _anyone_ could build an LED regulator using the general circuit layout, and ARC couldn't do anything about it. Note: if someone copied the _exact_ circuit layout, then ARC could get them for _copyright_ infringement, but any serious competitor would design their own circuit board and get around this.

But in a microcontroller based circuit, the actual code in the microcontroller is also protected by copyright, meaning that anyone who wanted to copy the ARC LS-4 would need to develop quite a bit on their own, making it a 'fair' competition.

-Jon

[/ QUOTE ]
Microcontrollers are not that hard to program...

Check out http://instruct1.cit.cornell.edu/courses/ee476/ - Our second lab last year was PWM dimming with single-button control and it took only an hour or two to code.

 

[Jonathan]

Hey,

Did anyone happen to archive the Speleogroup pages? I'd actually like to build this circuit, and while I have my own schematic and PCB layout already mostly finished, I'd like to compare for clues.

But it appears that the site is down /ubbthreads/images/graemlins/frown.gif

-Jon

 

[Tweek]

I saved the two circuit pages, if you'd like. Right here...


Chris

 

[tonyb]

I have a much simpler way of dimming with the ZLT circuit. I'm working on it right now, I,m about to etch a test board.

 

[Jonathan]

[ QUOTE ]
Tweek said:
I saved the two circuit pages, if you'd like. Right here...

Yes, Thanks!

-Jon


Chris

[/ QUOTE ]

 

[mfc]

> who solders this stuff

I did. In my late forties, and I'm a convert -- much quicker and less fiddly than through-hole. And one side of the completed board is insulation all over .. much nicer in confined spaces... :-)

Mike Cowlishaw [sorry about delay in response, was away caving in Spain.]