7 color led with two leads??

Using Arduino LEDs and Multiplexing
1

I recently came across "Trucking accessory" that claims to glow seven different colors. The accessory is made up of a small lamp with I took apart to find one LED (the accessory itself was turned out to just be an LED glued to a screw and a nut). The weird thing is that the LED only has two leads, unlike other multicolored LEDs which have three. I hooked it up and used the blink sketch, but I only get red. Any chance someone here can help get all the colors going? ill send one of these to the first person who helps me get it working!

Thanks,

Nick

2

It works without microcontroller intervention.
Cycles through colours on its own.
There's a little chip on the die, makes it all happen.
Just apply 3V and it does its thing.
That's all.

3

Runaway Pancake probably has it , but since I want one, I am going to venture another possibility.
It is bidirectional, and their ad that claims

to glow seven different colors

, is really just variations of the two colors.
Can you connect it forward, and backward?

Who gets the led? LOL

4

Runaway Pancake was right! this thing is really cool!!! Ill give you guys both one! pm me and ill send em over.

5

@ Runaway Pancake, great call.
is that 7 different LEDs, or combinations of 3?

6

There are 3 distinct elements (R-B-G).
If you look at it with a microscope or magnifying glass, you can see the little black controller chip.

Emphasising that it's likely a 3V device.
(Diminished MTBF given 5V - just sayin'.)

I have a bag-full, jackwp can have mine.

7

Yah pancakes right, its its rgb and it slows cycles to it get different colors. Its actually really cool...it looks like some sort of cool mood light! heres a pic of it reflecting on my wall: Imgur: The magic of the Internet

8

I too have a bag full - dirt cheap from eBay.

There are two variants; ones that slowly fade through different colours, like (one of) my mice, and the more common ones which fade and flash which get quite annoying after a short time.

A couple of mice I have bought had them wired directly to 5V (or possibly through a resistor) and failed in short order. When I replaced the LED, I added a couple of diodes in series to reduce the voltage and the replacements have been working fine since - mind you, they are the "flashy" sort not the faders.

I am a little concerned about using the "LED tester" on these as it supplies 9V through resistors as an essentially constant-current drive. On these sequenced LEDs, the load continuously varies and if they fade nearly out, the voltage will go towards the full 9V. In fact, since they fade using PWM, the chip must be subjected to the higher voltage every time the LED is turned off.