Testing Neopixel Strips

[mrlemon]

Hello from Seattle!

My students and I have begun building a neopixel saber.

We've assembled the paired neopixel strips, as Madcow demonstrates in his excellent video, Plecter Pixel Blade Construction.

One student has wisely asked, "Is there a way to test the pixel strips before we solder the wires to the PCB and assemble the blade?"

Thanks, as always.

Cheers,
- Mike Lemon

[darth_chasm]

This is the little test rig I made for testing the Illumicore crystals sold in the shop. It’s an attiny 85 loaded with a test program and uses pogo pins for quick connection to the pixel pads. Simple, easy, cheap.

[mrlemon]

Thanks, Darth.

What's the voltage? I'm not sure what load to use ...

Best regards,
- Mike

[darth_chasm]

No problem. It’s usb powered. +5v. If programming a tiny is too troublesome, you can always use an arduino pro mini or pro micro. Or even a seeed xiao.

[mrlemon]

Thanks!

We have arduino kits, but I want to avoid any more complicating steps - she's looking at it more simply.

The neopixel strips haven't been soldered to the PCB (she just has the two strips stuck together with the three wires from each strip), so she's considering just clipping a battery or batteries to the positive and negative wires from each strip for a quick check of the connection.

I haven't built a neopixel blade, so I'm not sure what resistance or current to use for a quick check.

Is it possible to use a 7.4V battery to check for illumination?

Thanks, as always!
-Mike

[darth_chasm]

That’s too much voltage for the strips. Ws2812 has an operating voltage of I think 3.8-5V. Plus you need data to see any illumination. That’s why the microcontroller is used. If you have arduino kits you could simply upload the adafruit test sketch and go from there.