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Question: RGB Light Strips and Battery Pack... do I need a r
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Question: RGB Light Strips and Battery Pack... do I need a r

by cassnat on Sun May 18, 2014 8:37 pm

This is my first project with Arduino and RGB light strips. I am working on making cylon lights for our Airstream Basecamp! So close!!

So, everything is programmed up and I was just trying to connect it to the battery pack. The plan was to wire both the Arduino and the light strip to the battery pack. I have soldered a diode in place after the battery pack.

Since I plan on using 4 AAA alkaline batteries, the voltage is 6V. Everything I have read says not to exceed 5V on the strip and I believe the Arduino also uses around 5.5V.

So, do I need to put a resistor between the power and the strip?

Could I solder a DC jack to the battery pack and run everything that way? Right now when plugged through the USB it is being powered that way (I put the 5V wire into the 5V pin on the board.)

Please let me know if you need any more information.

Specs:

OSEPP Uno R3 Plus (http://osepp.com/products/arduino-compa ... o-r3-plus/) - Bought this before I knew about you guys!
Digital RGB LED Weatherproof Strip LPD8806 (https://www.adafruit.com/products/306)
Battery Pack (https://www.adafruit.com/products/830)

BTW, love your tutorials!! I especially learned a lot from the soldering one since this is my first time!
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cassnat
 
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Re: Question: RGB Light Strips and Battery Pack... do I need

by adafruit_support_bill on Mon May 19, 2014 6:01 am

There are a few options for powering strips by battery. See this tutorial for details: https://learn.adafruit.com/battery-powe ... and-strips

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Re: Question: RGB Light Strips and Battery Pack... do I need

by cassnat on Mon May 19, 2014 10:21 am

Thanks. I have looked at all of those tutorials in depth. That is how I knew to put the diode in place.

It still does not address my question about reducing the voltage or using the dc jack.

Can you please review my question again?
cassnat
 
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Re: Question: RGB Light Strips and Battery Pack... do I need

by cassnat on Mon May 19, 2014 10:24 am

Let me explain a bit better... the diode is not dropping the voltage down. I am still registering 6V after the diode was put into place. I can send you a pic of that if you like :)
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Re: Question: RGB Light Strips and Battery Pack... do I need

by adafruit_support_bill on Mon May 19, 2014 10:33 am

What kind of diode are you using? Are you measuring it under load? At zero current, the voltage drop will be negligible.
http://en.wikipedia.org/wiki/Diode
Image

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Re: Question: RGB Light Strips and Battery Pack... do I need

by cassnat on Mon May 19, 2014 10:48 am

I'm using the diode from that tutorial. I purchased it from your site.

I was not testing with any load because I did not want to burn the strip out. So, if I understand correctly, I just need to wire everything up now like in the diagram and I will be fine?

What about the battery to the arduino dc jack, then wire the strip to the arduino? Would that work to power just a couple meters?
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Re: Question: RGB Light Strips and Battery Pack... do I need

by cassnat on Mon May 19, 2014 10:53 am

And by load, I hope you meant with everything attached. I only tested it with the battery pack and diode.

Noob question, I understand :)
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Re: Question: RGB Light Strips and Battery Pack... do I need

by adafruit_support_bill on Mon May 19, 2014 10:58 am

I just need to wire everything up now like in the diagram and I will be fine?

Yes. That should be fine. As soon as the leds start drawing current, the voltage should drop across the diode.

What about the battery to the arduino dc jack, then wire the strip to the arduino? Would that work to power just a couple meters?

No, for 2 reasons:
1 - The Arduino needs at least 7v at the dc jack to properly regulate.
2 - The Arduino's voltage regulator can't handle the load of that many leds

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Re: Question: RGB Light Strips and Battery Pack... do I need

by cassnat on Mon May 19, 2014 11:53 am

Ok... Great! Thank you for your help!
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