Multi Color LED Array for Conspicuosity and State Indication / General Science and Electronics / Forums

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Multi Color LED Array for Conspicuosity and State Indication

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Patrick

Tue Oct 02 2012, 07:31AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Hey All,

I need a 1 x 1.5 inch area square (or about) of brightly colored light. its for safety and machine state indication for those standing 5 to 25 feet away from my drone. Now i can know for sure if my machines props are ready to chop, without approaching.

im thinking of the below pic as a solution:

Obviousley, im mostly wanting a PIC like microcontroller to be able to select solid or blinking colors of Red, Green and Blue. I have the small 2.2 x 1.4 mm SMT LEDs... A whole bunch of them. (The mixing of colors is not needed at this time.)

the LEDs themselves are super bright pin-points that cant be ignored, and quickly become quite annoying
when in your face at 10 inches.

By staggering them im hoping the individual point blur into more or less a small rectangularish light source.

Do others know of a better way of accomplishing my goal? Im open to suggestions and physical changes to the layout, if others find a better way. I looked in all the places i could think of, to find industry standard type designs for this situation, (like traffic and room lighting) but i didnt find anything useful...

Once i find a practical layout, ill encapsulate the final devices in crystal clear casting epoxy for enviromental ruggedness.

On a related note, if im not mistaken:

for safety aircraft and surface vessels, customarily have:
a white light in their nose and tail.
a red light on the left.
and a green light on the right.

do i remember that right?

For UAV orientation Im hoping for:
left = red
right = green
in the tail a blue light.
I want this to be standardised, becuase ive seen ACE pilots better than me auger in there most favorite machines becuase they lost orientation. so if they can crash it in, so can i.

Shrad

Tue Oct 02 2012, 07:55AM

Registered Member #3215 Joined: Sun Sept 19 2010, 08:42PM
Location:
Posts: 780

sanded perspex or plexiglass over leds will diffuse brightness and be a bit like what you need, it will especially mix the colours if you draw a matric which is arranged like a CRT pattern

you can also use some RGB led ribbon

Patrick

Tue Oct 02 2012, 07:59AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Shrad wrote ...

sanded perspex or plexiglass over leds will diffuse brightness and be a bit like what you need, it will especially mix the colours if you draw a matric which is arranged like a CRT pattern

I may sand/fog up the epoxy coating for this purpose.

Shrad wrote ...
you can also use some RGB led ribbon

Can i get a source on this, please?

Shrad

Tue Oct 02 2012, 09:46AM

Registered Member #3215 Joined: Sun Sept 19 2010, 08:42PM
Location:
Posts: 780

this one, for instance

it seems simple enough to be glued on each side of your machine

there are many other models and I'm sure you could find other led densities and/or brightness

main advantage is they are already mounted and all you have to do is PWM three power lines

Ash Small

Tue Oct 02 2012, 12:07PM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Patrick wrote ...

for safety aircraft and surface vessels, customarily have:
a white light in their nose and tail.
a red light on the left.
and a green light on the right.

do i remember that right?

The regulations for surface vessels are as follows:

1349179652 3414 FT145077 Navigation Lights

I think that aircraft have a flashing white light instead of an 'all round' masthead light.

EDIT: Wikipedia says this:

Sulaiman

Tue Oct 02 2012, 12:15PM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140

Flashing leds are much more conspicuous than steady
so irrespective of the leds used have them flashing at 7Hz to 15 Hz.
Flashing also allows higher peak intensity/current for a given temperature rise.

Steve Conner

Tue Oct 02 2012, 01:24PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

The last surface vessel I was in had a white LED bike light taped to the stern, a red one taped to the bow, and a guy with a head torch.

Ash Small

Tue Oct 02 2012, 02:31PM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Steve Conner wrote ...

The last surface vessel I was in had a white LED bike light taped to the stern, a red one taped to the bow, and a guy with a head torch.

Was it a pedalo?

Seriously, though, Patrick's 'drone' could be lit with three LED's. A white one underneath, showing all round, a red one for port, placed on the side with appropriate shielding, and a similar arrangement with a green one on the starboard side. I'd probably make them all flash, certainly the white one.

Conundrum

Tue Oct 02 2012, 04:23PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

Use the ones found in modern LED backlights on LCD screens, they are bright as a distress flare and come in neat little sections.
Put one along each edge with a brightness flare if someone walks too close using a PIR sensor.

Steve Conner

Tue Oct 02 2012, 04:36PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

No, a quad scull.

Are the three LEDs enough to indicate which way the thing is facing? I guess they must be, unless the craft turns upside down somehow.

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