Recommended high density RGB LED strips - Page 1
Forum section: electronics / beginners

author: Youkai
author_rank: Regular Contributor
timestamp: May 09, 2022, 01:29:49 am
content: I'm working on a video game prop project that will have some lighting elements. I've looked at a couple youtube videos recently talking about putting LED's behind a diffuser and they recommend having a high LED density (100/meter) so the distinct LED aren't visible.Looking at Adafruit's site they have a 60 and 144/m neopixel strips. Those have warnings on them about the power consumption and "very very timing-specific" nature of the strips. Is that specific to these or are they just trying to keep people from making careless mistakes?For the whole project I'll probably need about a meter of LED which will be cut into various sections. I plan on chaining the sections together such that I can run it all off of one pin (assuming that makes sense in the final circuit with power consumption and all). The project itself will be somewhat space constrained but I'll be running half a dozen servos and the LED's and sound effects (though I have no idea how I'm gonna accomplish that yet). So I'll probably need a relatively powerful micro-controller; in case that matters as far as the clock regularity/timing.Does anybody have other recommendations on good RGB LED strips for this type of application?The Adafruit product:https://www.adafruit.com/product/1507

author: mon2
author_rank: Frequent Contributor
timestamp: May 09, 2022, 02:15:07 am
content: Just a comment on the LEDs. The inventor for this rgb led and communication is from the US. The first rgb LEDs (APA102) started at APA NEON in Taipei. The rest of the parts including this one is a clone of the original product. The timing is funky and not easy to implement on low end micros.Consider to use the pico pi or the micro RP2040 from the kit since it can support hardware state machine interfaces. This is like having a FPGA onboard so timing like this led requires is a breeze.Google 'neopixels pico pi' for ideas. Code support examples should be helpful.See the following for the real product:www.neon-world.com

author: themadhippy
author_rank: Super Contributor
timestamp: May 09, 2022, 02:33:18 am
content: QuoteMight be worth while getting a filter swatch book from the likes of lee or rosco,it contains samples of multiple diffusion materials. lee 129(heavy frost) works well a few cm from 30/meter tape,but does cut down the brightness a bit

author: SmallCog
author_rank: Frequent Contributor
timestamp: May 09, 2022, 03:01:55 am
content: Depending upon what you're making you could consider using the neon flex strip style LED, so that the diffusion is built in.https://www.led-shop.com.au/shop/smd5050-ip68-rgb-led-neon-flex-addressable/

author: Kasper
author_rank: Frequent Contributor
timestamp: May 09, 2022, 05:30:05 am
content: Most the strips I've seen have 3 or 4 pins. Power, gnd, data and maybe clock. The ones with the forth pin, clock, cost a bit more and are not as fussy about timing. If you're not buying lots of strips and don't care about a bit of extra cost, I'd go with the 4 pin ones. Adafruits dotstar strips are the easiest ones I've used.

author: Zero999
author_rank: Super Contributor
timestamp: May 09, 2022, 06:12:38 pm
content: Do the individual LEDs in the strip need to be addressable? If not, go with plain old passive 24V RGB LED strip. It's more efficient than the 5V variety and uses less current, so the cables can be much thinner.

author: Youkai
author_rank: Regular Contributor
timestamp: May 09, 2022, 11:15:03 pm
content: Quote from: Zero999 on May 09, 2022, 06:12:38 pmYes I need them to be. It's going to be about a meter total of LED separated into 5 or 6 different sections. Each section needs to be able to be controlled individually at a minimum and ideally I'd like to be able to do some kind of intensity/hue rainbow in each section. If I want to be able to wire them all up in a single strand I need them to be individually addressable. Based on the number of other things I need to control in the project I think IO pins are going to be at a premium.Quote from: SmallCog on May 09, 2022, 03:01:55 amThat's cool but I think too bulky for my needs. In some case the lights will only be providing "halo lighting" like you might see in a backlit keyboard. In those cases diffusion is unnecessary. There are a couple places where the LED will be exposed though and I'll put a simple acrylic diffuser over them.

author: eugene
author_rank: Frequent Contributor
timestamp: May 10, 2022, 04:46:05 pm
content: I'm going to repeat what Kaspar wrote about there being two general types of digitally addressable LEDs. One kind has just a single shared data pin (Adafruit calls them NeoPixels.) The other kind uses two pins on the microcontroller: data and clock. Adafruit calls these DotStars. The difference is described well on the Adafruit web pages.Obviously, the ones without the clock line use one fewer GPIO pins, but behind the scenes they are quite a bit more difficult to use. You can write your own routines to make them work if you enjoy that sort of thing, but most people use the Adafruit libraries, even with LEDs that they sourced somewhere else. It all works fine if you're using a microcontroller with plenty of flash, ram, and cpu cycles. I don't know for sure, but it seems likely that one of your counter/timers will need to be dedicated to the job. The library makes it simple and trouble free if the resources are available.The ones with the clock line require a second GPIO pin, but it's not hard to write your own code to bit bang the data. That may or may not be an advantage depending on the hardware you're using. A counter/timer is still used, but it can usually be shared with other timing code like like delay() and micros().

author: Kasper
author_rank: Frequent Contributor
timestamp: May 10, 2022, 06:29:03 pm
content: Quote from: eugene on May 10, 2022, 04:46:05 pmAdafruit has dotstar libraries also so you don't have to bit bang them.

author: tooki
author_rank: Super Contributor
timestamp: May 10, 2022, 06:51:31 pm
content: Quote from: mon2 on May 09, 2022, 02:15:07 amThis is complete nonsense. The APA102 is not even close to the first addressable LED, nor is it sensitive to timing, since it has a separate clock line.I don’t know whether they were the absolute first addressable LED, but the firstcommonaddressable LEDs were ones using the WS2812 drivers from Worldstar (those being a version of the WS2811 driver IC that was sold as a DIP IC).The APA102 came much later.

author: tooki
author_rank: Super Contributor
timestamp: May 10, 2022, 06:59:56 pm
content: Quote from: Youkai on May 09, 2022, 01:29:49 amI concur with the recommendation of the Dotstar (SPI-like with separate clock line) type of LEDs. The APA102 is the original of this style, but the clones have become more common, and in many cases actually exceed the specs of the original. (The most common clone is the SK9822, which I’ve used, and the HD107, which I haven’t tried but looks awesome.)In lieu of the Adafruit libraries, I suggest trying FastLED, because it supports basically every addressable LED out there. That means you could use Neopixel style LEDs now, later change to Dotstar type for the next production run, etc, with only the tiniest of code changes to tell it which LED type to use.

author: Youkai
author_rank: Regular Contributor
timestamp: May 10, 2022, 10:21:36 pm
content: Alright thanks for the info guys. When I get a little farther into the project I'll look at the specs of the NeoPixel and Dotstar type leds as well as their cost to pick the right one. One extra pin won't be an issue.