144 Neopixel powering setup

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orionlogic
 
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144 Neopixel powering setup

Post by orionlogic »

Hi,

I bought 144 Neopixel #1506. i try to connect but nothing happens. Whats wrong with my connections?
144led.jpg
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Thanks.

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adafruit_support_bill
 
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Re: 144 Neopixel powering setup

Post by adafruit_support_bill »

I don't see any connection to the Arduino ground. This should be the first connection you make.

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orionlogic
 
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Re: 144 Neopixel powering setup

Post by orionlogic »

Hi there,

Actually Arduino breadboard rail is powered both 5v and ground. It is not seen in this picture.

Any more ground connection need? Lie from the green jack ground (-) to arduino ground?

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adafruit_support_bill
 
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Re: 144 Neopixel powering setup

Post by adafruit_support_bill »

The strip must be connected to the Arduino ground. The more direct the connection the better. As noted, this should be the first connection made. Providing power and signal with no common ground reference can damage the strip.

http://learn.adafruit.com/adafruit-neop ... -practices

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orionlogic
 
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Re: 144 Neopixel powering setup

Post by orionlogic »

So you mean connecting - sign of the green jack with capacitor to Arduino ground? I did it and nothing happens.

Can i understand if the strip is damaged?

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Re: 144 Neopixel powering setup

Post by adafruit_support_bill »

Typically, if a strip is damaged, it will only affect the first pixel or two. After making sure you have solid ground and power connections, you can try running a jumper directly from the Arduino to the input of the second or third pixel.

This is a little tricky on the 144 pixel strips. the pixels are very closely spaced, so you have to touch your jumper wire directly to the input pin on the pixel.
The input pin "DIN" is pin 4. See the diagram on page 2 of the data sheet and note the position of pin 4 relative to the notch on one corner of the pixel.
http://www.adafruit.com/datasheets/WS2812B.pdf
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orionlogic
 
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Re: 144 Neopixel powering setup

Post by orionlogic »

Ok but my first question was something else.

I attach my updated setup. Is this set up look OK?
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adafruit_support_bill
 
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Re: 144 Neopixel powering setup

Post by adafruit_support_bill »

Is this set up look OK?
As I said earlier, the ground connection from the Arduino should go directly to the strip. As you have it, the Arduino ground is is connected to the power ground at the breadboard and then through a jumper to the strip. With a 144 pixel strip, there is a lot of current going through this path so there will likely be a considerable voltage drop. That will cause a 'ground bounce' at the strip, making the signal LOW actually lower than the ground. This is not good for the strip.

Also, your resistor should be at the strip end of the wire as described in the tutorial: http://learn.adafruit.com/adafruit-neop ... -practices
Place a 300 to 500 Ohm resistor between the Arduino data output pin and the input to the first NeoPixel. This resistor must be at the NeoPixel end of the wire to be effective!

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orionlogic
 
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Re: 144 Neopixel powering setup

Post by orionlogic »

I am so sorry, i am newbie in this, excuse my questions.

Here is my new setup. Ground connections from directly Arduino GND.
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Re: 144 Neopixel powering setup

Post by adafruit_support_bill »

OK. So now you are powering from one end and connecting the signal to the other end. That is OK. Just make sure that the signal is going to the input end of the strip. They should be small arrows printed on the side of the strip indicating the direction of signal flow.

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orionlogic
 
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Re: 144 Neopixel powering setup

Post by orionlogic »

Ok this is my last picture i guess.

Here i put the arrows on the strip.
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Re: 144 Neopixel powering setup

Post by adafruit_support_bill »

OK. That should be the right end for the signal. Have you tried the second or third pixel?

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orionlogic
 
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Re: 144 Neopixel powering setup

Post by orionlogic »

Ok, i managed to setup and i think there is a problem in googles sketch but strand test sketch is working properly. No dead leds.

Thanks for everything. However connecting this setup required 4 hands :)
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Re: 144 Neopixel powering setup

Post by adafruit_support_bill »

Great! Glad you got it working.

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