NeoPixel Rings problems

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Tsuguto
 
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NeoPixel Rings problems

Post by Tsuguto »

Hello,

I try to use NeoPixel Rings (24 and 16 x 2) with trinket but it doesn't work.
When I receive it I've try the goggle projet with the 2 16 pixel rings and this work but not perfectly.
Two days later I've tried again and this time it doesn't work at all.
There is just one LED who work when I disconnect the ground from the ring.
I've see the signal from the trinket in a scope and there is some mistake on pin #0 & #1 it's not very squared. Maybe I do something wrong who damage pin #0 & #1 and the NeoPixel rings ?

Can you help me?

I'm sorry for my poor english =/

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adafruit_support_bill
 
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Re: NeoPixel Rings problems

Post by adafruit_support_bill »

When I receive it I've try the goggle projet with the 2 16 pixel rings and this work but not perfectly.
What part did not work? If you post photos we can check your wiring.
There is just one LED who work when I disconnect the ground from the ring.
Do not disconnect the ground from the ring while there is power still applied! This will damage the ring. The ground should always be the first wire connected. See this guide: http://learn.adafruit.com/adafruit-neop ... -practices

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Tsuguto
 
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Re: NeoPixel Rings problems

Post by Tsuguto »

Some pixels weren't bliking but it doesn't work anymore so I can't post photos.

Image
I use this wiring without the batery because I use USB for prog.

Maybe I've done something wrong because I don't use cap & resistor like the photo. Is it very usefull?
Does the trinket is damage too?

I try to use 4 neopixels V2 with gemma and a 3.7V LiPo (2500mAh) and it work. Should I add cap & resistor? (and witch type?) I'm afraid to damage it too.

Thanks.

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adafruit_support_bill
 
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Re: NeoPixel Rings problems

Post by adafruit_support_bill »

I use this wiring without the batery because I use USB for prog
There is no power on the BATT pin when powered by USB, so that wiring will not work.

A capacitor should not be necessary with battery power. The resistor (~330 ohm) on the data line is good protection against damage due to noise on the data line).

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Tsuguto
 
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Re: NeoPixel Rings problems

Post by Tsuguto »

I made a mistake, I'm connected on the USB+...
But I'm sure that I have 5V on Bat+

What can I do with my rings if they weren't working at all?

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adafruit_support_bill
 
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Re: NeoPixel Rings problems

Post by adafruit_support_bill »

Damage typically affects the first pixel. You can try connecting the signal wire to the input pin of the second pixel in the ring. Often, the rest of the ring will light up.

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Tsuguto
 
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Re: NeoPixel Rings problems

Post by Tsuguto »

20140124_144529.jpg
20140124_144529.jpg (79.06 KiB) Viewed 1530 times
It still not work =(
I've tried everything I can do ....

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adafruit_support_bill
 
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Re: NeoPixel Rings problems

Post by adafruit_support_bill »

If you contact [email protected] with a link to this thread we can send a replacement. Please follow the best practices in this guide to avoid problems in the future:
http://learn.adafruit.com/adafruit-neop ... -practices

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Tsuguto
 
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Re: NeoPixel Rings problems

Post by Tsuguto »

Hello,

I have an other question, I use a 3V Trinket with a 3.7V LiPo like the picture that I've posted before.
You say that neopixel use a 5V logic command (http://learn.adafruit.com/adafruit-neop ... -practices) but the tutorial (http://learn.adafruit.com/kaleidoscope- ... nket-gemma) say that will work with the 3V.
What I have to do? - Trinket 3V + 3.7V Lipo (better)?
- Trinket 5V + 3.7V Lipo?
- Trinket 3V + 3.7V Lipo + logic level converter (worst for me)?
- Trinket 5V + 5V source (no idea ton make this source)?

Sorry for my poor english.

Thanks

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pburgess
 
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Re: NeoPixel Rings problems

Post by pburgess »

The "5V logic" is a simplification, for the sake of brevity in the tutorials. This is assuming a 5V power supply for the pixels.

More accurately, the logic voltage must be at least 0.7 * Vdd. With a 5V power source, that means 3.5V or better, which is why 3.3V devices won't work.

If Vdd into the pixels is lower (the datasheet says they're good down to 3.5V), the logic threshold is correspondingly lower and may be reasonable for a 3.3V device, in which case no level shifting is needed. For example, 3.7V LiPo = = ~2.6V minimum logic level (but anything up to Vdd -- 3.7V --is also acceptable).

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