Neopixel device code

I got a bit confused looking at the various discussions about neopixel code - what works and what does not. Any suggestions on code that seems to work reliably? I thought I might dabble with some neopixels.

The code doesn’t seem to be the issue… I believe its the voltages for power and clocking. I have never had any issues, but other have. I’ve powered various Neopixels from all of the MakeDeck dev boards using 3.3V, 3.0V, and 3.7V Lithium-ion batteries.

@MakeDeck – I have no problem introducing a voltage level shifter if that helps mitigate the issues. So…your github "Neopixel-Ring-Wearable-Project code seems to work fine? For what I’m thinking about, I’d likely power with a 5VDC adapter and the voltage shifter might smooth the way.

Yes, I have never experienced the problems that others have, but I have only ever used Neopixel boards from Adafruit. I’ve never had to use a voltage shifter. I do have some WS2812 chips to build my own boards, but that project is still on the back burner.

I’ve had no luck with them :frowning:

It’s a pity because I think it somewhere where the imp could really shine

I’ve heard a bit about level shifters and need to investigate seeing whether I can bring my pixels under control.

If there were to be an interface board (either external or with and imp embedded) it would be nice if it supported all the similar devices out there, I understand it’s up to a dozen now! There is even a kickstarter for a usb board for them.


To quote Adafruit:

“NeoPixels powered by 5V require a 5V data signal. If using a 3.3V microcontroller you must use a logic level shifter such as a 74AHCT125 or 74HCT245. (If you are powering your NeoPixels with 3.7v, a 3.3v data signal is OK)”

From learn.adafruit.com/adafruit-neopixel-uberguide/best-practices

I was thinking of using a ready-made shifter board like this sparkfun model

https://www.coolcomponents.co.uk/logic-level-converter-bi-directional.html

What do you think, will it do the trick or am I risking more money?

The reason I didn’t use one at the time is the vibe of the forum at the time was that it wasn’t needed.

For a couple of quid, it seems worth the risk to me. I was going to try one of these:

http://shop.pimoroni.com/products/adafruit-4-channel-i2c-safe-bi-directional-logic-level-converter

I use Adafruit Neopixels, with 5v power and direct drive from the imp, and I have had no problems. I am probably just lucky, I know I should have used a series protection resistor etc, but it just worked, just as well as from a 5v Trinket.

Yeah, but I was always the kid in class that got caught, so I have to do it by the numbers as now even in adulthood if I cut a corner, it always ends up biting me!

Assorted NeoPixels and a level-shifter (see link in my last post, above) arrived in the post today. Soldered 'em up, wired 'em up, loaded some code and the Electric Imp NeoPixel class onto a spare imp and… nothing

And then (ahem) I realised I’d connected MOSI and MISO the wrong way round. A quick swap and now I have a very brightly glowing LED. Works a treat.

NeoPixel is powered at 5V off April’s VIN pin (I’m running off a USB AC adaptor), and the level-shifter boosts the MOSI-fed data line from the imp’s 3.3V to 5V.

I’ve got my shifter too, just need to find that ever elusive time to do it

What which “neopixels” did you get? I was surprised at just how different types and manufacturers of RGB LED there are!

A pack of these from Adafruit

oh, I read meant assorted to mean different ones rather a quantity of the same type.

I’ve also got some rings and other bits and bobs.

So I guess the obvious question would be, which “digital rgb led’s” is there currently code for (other than the WS28xx neopixels) and are all the different library’s expecting the same inputs so you can plug and play?