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Asked — Edited

Wall-E Led

How did DJ connect wall-e's led for his eye to the ez-b?


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I assume he used the darlington transistor switching circuit and used one of the digital ports to enable/disable the light.

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ok is there a simpler method to this(limited abilities cause i'm 12)
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In short, no.

The circuit I posted is very simple, you wont find simpler short of wiring the signal wire to the LED - which is not advised as the signal wire doesn't carry anywhere near enough current to power anything.

You can do the circuit either in line (how I did mine), on a prototype board or on a breadboard (solderless).

Why do you want it simpler? If you let me know what you want to avoid doing I may be able to tell you the best way to go about it.
hold on for a sec im trying to answer my own question(tired from sledding)
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Here is another wiring diagram which may make it look simpler.

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And my in line version (however the resistor is hidden by heat shrink)

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ok so E connects to the C wire. C is the negative. positive is ? seems similar to a motor controllor set up.
that thing with the hole in the end is the transistor which manages the power? or what purpose does it serve?(sorry. not good with electrical)
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Quick and easy 7 step guide to wiring it up;

1. Snip off the female end of a servo extension
2. Solder the resistor to the base of the transistor (left hand pin)
3. Solder the white wire of a servo extension to the other side of the resistor
4. Solder the red wire of a servo extension to the positive of the LED or lamp holder
5. Solder the black wire of a servo extension to the Emitter of the transistor (right hand pin)
6. Solder a short piece of wire from the Collector of the transistor (middle pin)
7. Solder the other end of the wire to the negative/ground of the LED or lamp holder

Then just connect the servo extension on to a digital port of the EZB. For instance D0

Now, in ARC add a Set Digital control (add, digital, set digital), assign D0 in the config and click the button to turn on and off.
ok thanks.

found a skimatic to blinkM. seem simpler and offers a bit more but then i have to pay money which i used to buy the wall-e toy and ez-kit.
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Do not use a resistor or transistor for an LED with the EZ-B.

If you are powering an LED, connect one wire to a EZ-B Digital port and connect the other to GND.

When you enable the port, the LED will glow. Use a Digital Control to turn ON and OFF the port that you connect the LED to.

LED's require the polarity to be correct. The longer wire of the LED is + and the short wire is -

You can also look inside the LED and notice the electrical connections. You can look and recognize which is - and which is +

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ok thanks Dj i thought about that for a sec. For the blinkM though...
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The BlinkM would need 4 wires soldered to it, the TIP transistor circuit needs 4 wires soldered.

BlinkM is great as you can change the colour of the LED, fade from one colour to another and a lot more but it costs more and is bigger. If your Wall-E is the same size as the one I have waiting to be hacked then there isn't much room in the eye. You could probably make it fit but it would be easier to make the TIP circuit.

I've been meaning to do a good tutorial for the TIP circuit for a while, if I get chance tomorrow (and if I can manage to de-solder one of the TIP transistors I soldered to a proto board which I never used in the end) I will knock one up.
sure i guess. i think that will help future roboteers like me with this topic.
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I still learn something new every day, I didn't realise that you can power an LED from the signal wire.

So yes, DJ has a much simpler solution. Snip off a servo extension, wire the LED directly to the black and the white wires just like in DJ's pictures.
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Yep, they will do.
k i was getting skeptical about thoughs wondering if they were right or not.

Thanks. when i start my project in the project showcase in march ill give you and Dj a shout out.
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On the I2C BlinkM, you seem a little confused on how to wire it up. It connects to the I2C port not to the Digital ports. So it has 4 wires from the I2C header on the EZB to the 4 connections on the BlinkM. Just marry up the connections on both... that's if you go down that route.