Motion activated LED lamp, noob may have bitten off more tha

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punyhumans
 
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Motion activated LED lamp, noob may have bitten off more tha

Post by punyhumans »

I am trying to reproduce an object described in Scott Lynch's Gentlemen Bastards books, called an "alchemical lamp". Basically, it's a ball that lights up like a light bulb when shaken, and will fade after a few minutes.

I found the attached design http://www.instructables.com/id/3D-prin ... on-sensor/ that is really close to what I want, consisting of:

- 3.3v Trinket https://www.adafruit.com/products/1500
- segment of 19 LEDs from https://www.adafruit.com/products/1507
- 100mAh lipo battery https://www.adafruit.com/products/1570
- Flora accelerometer https://www.adafruit.com/products/1247

Now, the demo video looks ok, but I want just warm white light, and I feel that the 5v LEDs would be under-powered for that purpose.

so what if I tried:

- 5v Trinket https://www.adafruit.com/products/1501
- 5v lipo booster https://www.adafruit.com/products/2465
- 4400mAh Lion battery https://www.adafruit.com/products/354
- segment of 28 NeoPixel LEDs https://www.adafruit.com/products/1507
- Flora accelerometer https://www.adafruit.com/products/1247

I realize the code would have to be rewritten to account for the warm light and the timing, but could this even work the way I'm imagining it to supply 5v to the LEDs? How would the wiring incorporate the 5v booster? Should I stick with original components?
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adafruit_support_bill
 
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Re: Motion activated LED lamp, noob may have bitten off more

Post by adafruit_support_bill »

That should work. The battery plugs into the booster and the 5v output of the booster goes to the GND and BAT pins of the 5v Trinket and the Pixels. The Trinket itself has enough memory for up to about 100 pixels.

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punyhumans
 
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Re: Motion activated LED lamp, noob may have bitten off more

Post by punyhumans »

Thank you the advice! It occurs to me that the accelerometer is rated for 3v, and the trinket I'm using is 5v, will that be a problem when I want to solder them together?

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Re: Motion activated LED lamp, noob may have bitten off more

Post by adafruit_support_bill »

That would be a problem. You really should use a 3.3v Trinket. The 5v logic levels from the 5V trinket will damage the Accelerometer which is designed to work at 3.3v.

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punyhumans
 
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Re: Motion activated LED lamp, noob may have bitten off more

Post by punyhumans »

That makes sense, thanks! I switched to a 5v Trinket (and added the 5v Li-Po booster) because I wanted to be able to power the LEDs at full brightness, If only briefly. Feel like a waste not to let them do their thing.

If I switch back to a 3.3v Trinket, will that still work properly with the voltage booster? Or should I just stick to the schematic?

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Re: Motion activated LED lamp, noob may have bitten off more

Post by adafruit_support_bill »

Probably best to stick with the schematics. Trying to drive pixels runing at 5v with a 3v processor doesn't work so reliably. You would need to add a level shifter for the control signal also. The difference in brightness between 3.3v and 5v is nt really noticeable.

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