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Back-lit Picture Frame Guidance
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Please be positive and constructive with your questions and comments.

Back-lit Picture Frame Guidance

by Driagan on Mon Jan 13, 2020 8:32 pm

Hello,

I'm rather new to building electronics, so I was hoping to get some guidance or maybe pointed in the right direction for how to do what I'm thinking of (maybe an online tutorial of you know of one similar!)

I have a 3d printer and I'm planning on printing a 3d lithograph of an image of my partners mother and father together as a gift. I'd like to put it into a picture frame and have a switch on the side that turns LEDs behind the lithograph on/off.

For the physical setup of building the lithograph and frame, I'm pretty good with that, I can design and 3d print it as needed.

The part I'm having issues/concerns with is how to do the electronics part. Since I really only need a switch and LEDs, I'm thinking of going with the Trinket M0 (https://www.adafruit.com/product/3500), which appears to be the smallest microcontroller. For the lights, I just need to light up a picture from behind with uniform white light, a lot of the LED strips seem to offer setting the color of individual LEDs and changing color. A lot of things I don't need for my goal.

So, my questions are:
* Would the Trinket M0 be a good board choice for this?
* What LEDs would you recommend for lighting?
* How would I go about powering the Trinket?
* Would just providing power to the Trinket be enough, or do a need a separate power source for the LEDs?

Driagan
 
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Re: Back-lit Picture Frame Guidance

by adafruit_support_bill on Mon Jan 13, 2020 8:56 pm

If you just need to turn the lights on and off, there is no need for a microprocessor. You can just use a switch, a 12v power supply and some analog LED strips. We have both cool and warm white versions:

https://www.adafruit.com/product/887
https://www.adafruit.com/product/357

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Re: Back-lit Picture Frame Guidance

by franklin97355 on Mon Jan 13, 2020 9:04 pm

You could use plain LEDs or strips like this https://www.adafruit.com/product/887?length=1 a switch and a power supply of 5 to 12 volts depending on the brightness you are looking for. No processor or programming needed.

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Re: Back-lit Picture Frame Guidance

by Driagan on Tue Jan 14, 2020 12:57 pm

Thank you both!

So it sounds like I could just use a power supply connected to LEDs, so I'm thinking of going with this power supply: 12V DC 1000mA (1A) regulated switching power adapter - UL listed

Then this switch, as it would be easy to connect on the power line: In-line power switch for 2.1mm barrel jack

And these lights: Cool White LED Weatherproof Flexi-Strip 60 LED

So, my last question (probably) is how do I connect the barrel jack from the power/switch to the lights? The closest connector I can see is something like this 2.1mm DC Barrel Plug to Alligator Cips, but I don't need alligator clips when I'm finished, so probably just strip the wires and solder them to the lights?

Driagan
 
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Re: Back-lit Picture Frame Guidance

by adafruit_support_bill on Tue Jan 14, 2020 1:33 pm

Each 3-pixel segment takes about 60mA. If you use all 60 pixels, the strip will try to pull about 1.2A. So you would need a power supply capable of at least that. The next size up we carry is 5A. https://www.adafruit.com/product/352 You can probably find a 2A supply online somewhere.

But if you don't need the full strip, you could cut it at 5cm (3 pixel) increments. The 1A supply would power up to 48 pixels.

This barrel adapter an easy way to connect: https://www.adafruit.com/product/368
We also have a panel-mount jack: https://www.adafruit.com/product/610

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Re: Back-lit Picture Frame Guidance

by Driagan on Tue Jan 14, 2020 2:24 pm

Perfect, thank you very much! I have a pretty good idea what I'll buy/use!

Driagan
 
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Joined: Thu Sep 05, 2019 4:56 pm

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