Make your own LED lighting

For discussions about bikes and equipment.
james01
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Postby james01 » 27 Oct 2008, 2:11pm

insanityideas wrote:I love commuting by bike, you get to talk to people.

Yes, and you learn all those wonderful new words shouted by those nice motorists out of their car windows :D

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lauriematt
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Postby lauriematt » 27 Oct 2008, 2:12pm

james01 wrote:
insanityideas wrote:I love commuting by bike, you get to talk to people.

Yes, and you learn all those wonderful new words shouted by those nice motorists out of their car windows :D

off topic now...but i always wondered if car drivers could hear the abuse i shouted at them as they cut me up

....turns out they can - as one gave me the two fingred salute! :lol:
WHAT DOESNT KILL YOU .... CAN ONLY MAKE YOU STRONGER

insanityideas
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Postby insanityideas » 27 Oct 2008, 10:10pm

Having had a nights sleep following my impulse buy last night I thought I should post a slightly less vague explanation.

I have bought myself a microcontroller on a development board, something I have been tempted to do for a while but have have stayed away from on the grounds of cost and or complexity (nice idea but probably never get it to work stuff).

I changed my mind because I discovered one designed to be easy to use by hobbists and also cheap. Loads of people are using them to make cool little electronic toys and robots. You can find the details here: http://arduino.cc/en/Main/ArduinoBoardDiecimila and buy them from a UK supplier here: http://www.coolcomponents.co.uk/catalog/index.php

The really high end bike lights that you see with funky little fuel guages or other fancy features or that claim to be microprocessor controlled are using something either identical or very similar to this with their own software running on it. I have linked to the larger development board version, but you can get a super miniature one as well.

Out of the box this has digital input/output pins (for switches and LED's) including some that have built in PWM capability (very useful for dimming things). And some analog sensor inputs (useful for measuring things like battery voltage or temperature). It can also communicate with your PC or run standalone. You can also get all sorts of sensors including a GPS and accelerometer.

I am waiting for mine to be delivered so I can do some experimenting... doing anything more to my bike lights is not my aim right now, but it would be tempting in the future. But I will be able to use it to datalog battery discharge while testing my lights, to get an accurate runtime figure.

I am sure I will do some small scale experimenting with flashing and dimming LED's, but thats about all you can expect from me in the short term.

If anyone else thinks this is cool and wants to have a go and post their results that would be great! The actual software coding to make lights work on this is pretty trivial. You would need a FET to drive high power LED's off the digital outputs of this device though (something I already do in my 555 timer circuit that currently flashes my LED's).

insanityideas
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Postby insanityideas » 27 Oct 2008, 10:50pm

Somewhere on here a while back some comments were made about the legality of flashing lights, high powered lights etc. Thanks to another thread on this Forum I now have a better understanding of the law!!!

For the most part fit BS approved lights, and do whatever the hell you like... but you can also check your lights conform to the relevant BS, mark them as such, and use them!!! (well in theory anyway) Unfortunately as the BSI charge £80 for a copy of the document I can't check all the details, but I am sure I exceed 4 candela.

Interestingly most bike lights you can buy in the shop arn't BSI approved either, so they clearly can't afford £80 for the book.

If your lights only flash, current legislation says they don't need to be BS compliant, but thats only until they update the relevant BS.

http://www.dft.gov.uk/pgr/roads/vehicles/vssafety/guidanceaboutlightsonpedalbi4556

The dft seem concerned that lights are fitted and bright enough, and then that they are BSI compliant, so building your own light satisfies most of that.

GeoffL
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Postby GeoffL » 28 Oct 2008, 8:01am

Also, the 2005 amendment that permits flashing front and rear lights requires that the flashes be of equal duration, the intervals between flashes be of equal duration, and the flash rate between 60 and 240 flashes per minute. IOW a constant "single" flash pattern.

Geoff

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Phil_Lee
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Postby Phil_Lee » 28 Oct 2008, 5:52pm

GeoffL wrote:Also, the 2005 amendment that permits flashing front and rear lights requires that the flashes be of equal duration, the intervals between flashes be of equal duration, and the flash rate between 60 and 240 flashes per minute. IOW a constant "single" flash pattern.

Geoff


However, it doesn't say that all lights that are fitted need to be flashing at the same rate, so patterns are possible with multiple emitters, as long as each emitter has a steady flash rate between 1 and 4 hz :twisted:

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EdinburghFixed
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Postby EdinburghFixed » 29 Oct 2008, 9:24am

My Cateye LD1100 has two independent banks of lights, which can do all sorts of things but the problem is when the banks "de-sync" completely, motorists simply see a 50% brightness solid light, which seems a bit pointless.

Only the steady mode actually shines full brightness at oncoming drivers - but there are two buttons and a total of 10-ish modes to toggle!

Doh!

texteditor
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Rear light

Postby texteditor » 29 Oct 2008, 1:01pm

Bought a string of 20 red LED's from the pound shop, they jast 36 hours before substantially dimming on 2 AA rechargeable batteries.
texteditor.

insanityideas
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Postby insanityideas » 29 Oct 2008, 9:18pm

Well emergency vehicle (and AA vans) strobe lights all work on an irregular flash pattern... so if its good enough for them, I want some of it.

I have also noticed quite a few of the newer bike lights on other people's bikes have an irregular pattern to them.

Judging by the news reports from Oxford the police are concentrating on enforcing actually having lights right now (a good thing).

I just want to be as visible as possible, without causing undue offense to other road users. And if you squint enough it looks like a slow on-off flash, its just the on bit has a strobing flicker to it.

I should really do something useful and post up some pictures and a description of how I made my lights, for other people to use or learn from.

rjb
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Re: Make your own LED lighting

Postby rjb » 16 Aug 2017, 7:50am

Link here to using a GU10 bulb as a dynamo headlight. viewtopic.php?f=5&t=116628
:wink:
At the last count:- Focus Variado, Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin, Raleigh 20, Falcon K2 MTB dropped bar tourer, Longstaff trike conversion on a Falcon corsa. :D