Rookie Project Advice

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croff110
 
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Rookie Project Advice

Post by croff110 »

Hi everyone this is my first project in this realm and I am looking for a little guidance. I am planning to make a sign consisting of 4 letters lit with LEDs. I have listed the parts that I have selected so far from my loose research. Any feedback would be appreciated. One question I have specifically from comparing this project to similar projects shown on the website is, “Is this overkill?”. I am using the NeoPixel Ring Lamp By Ruiz Broth project as a loose guideline and they only use a USB power supply but the guides I have seen suggest a larger power supply. With the materials that I have listed below would I be able to use the basic wiring layout that is provided in the above mentioned project guide.?

LEDs - Approx 100LEDs of White 30 NeoPixel Digital RGB LED Strip https://www.adafruit.com/product/1376?length=1
Controller - Adafruit Metro Mini 328
https://www.adafruit.com/product/2590
Power - 5V 10Amp Power Supply
https://www.adafruit.com/product/658

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dastels
 
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Re: Rookie Project Advice

Post by dastels »

100 NeoPixels will need at most 6A (3 LEDs per pixel at 20mA if fully on): 60mA per pixel * 100. So you're power is taken care of.

The '328 has 2K of RAM and the NeoPIxels will use 600 bytes (3 bytes for each pixel). That leaves about 1400 bytes for your code to use. That may or may not be a problem, it all depends on what your code wants to use. If it needs more you'll need an MCU with more memory.

If all you need to do is control lights, then that hardware should do the job (with the cavaet about RAM). Make sure you read https://learn.adafruit.com/adafruit-neopixel-uberguide.

Dave

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croff110
 
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Re: Rookie Project Advice

Post by croff110 »

Thanks! If you could could you give some feedback on this first run at the a circuit diagram I'd really appreciate it. I am hoping to power this off one source.
circuit 1.png
circuit 1.png (98.88 KiB) Viewed 106 times

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dastels
 
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Re: Rookie Project Advice

Post by dastels »

Looks good generally, but a couple things:
- Vin can't (due to the NeoPixels) be higher than 5v.
- long runs of neopixels should be powered every meter. to avoid looses along the power traces. They use a lot of current which means that power line losses can add up quickly resulting in pixels at the end of the strip not getting enough voltage. It looks liek you'll have 2 or 4 meters. Only 100 pixels total so I'm thinking you might be able to get away with applying power at each end if that makes it easier. If you do that, you really fat wire to run power to the far end, ideally put the power source at the middle of the strip rather than at one end.

That guide covers powering strips.

Dave

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croff110
 
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Re: Rookie Project Advice

Post by croff110 »

My best route will be to just run a separate power source to the board. Thanks again!

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