Wiring Programmable LEDs

This video demonstrates different approaches to wiring microcontrollers to common "clockless" LED strips (i.e. "Neopixel" WS2811, WS2812, WS2813, WS2815) which all use the same protocol transmitted at 800kHz on a single 5V data line.

For simple circuits and only a short length of LEDs, it may be ok to take the data signal directly from the GPIO pin of an Arduino/ESP8266/ESP32. But for a more robust approach, I'll explain why you should add a series resistor to condition the data signal and protect the GPIO pin, a capacitor to smooth out power fluctuations, and a logic level convertor to step up the output from a 3.3V microcontroller to the 5V logic required by the WS28xx specification.

To carry the data over a greater distance, you could also consider using differential signalling, as demonstrated using a pair of RS485 transceivers. This is much more tolerant of noise, and allows you to transmit a signal 10 metres or more - ideal if your LED strips are located some distance away from your controller, or if you need to introduce a space between consecutive LEDs in the middle of the strip.

Timings
00:00:00 - 00:01:20 Introduction
00:01:21 - 00:02:46 Direct connection
00:02:47 - 00:06:30 A more robust circuit
00:06:31 - 00:10:24 Differential signalling for long distance
00:10:25 - 00:12:14 Backup data line

[pileofstuff]

Thanks for including that bit about the backup line.

[RoterFruchtZwerg]

Great to see someone actually using the correct level-shifter/buffer for that purpose 👍 The HCT125 is available in a small single gate (1G) version, the 74AHCT1G125GW, which makes for a perfect small in-line converter board. Also, if you can't get a 125, basically any AND/OR/XOR gate will do. So any 74xT1G[125, 34, 32, 17] should work.

[koalahamlet]

Fantastic explanation dude! I was just talking to a professional LED engineer the other week and he mentioned this technique about how to smooth out data signals over a great distance. Please keep these incredible videos coming, You have a true gift for making hard things simple.

[lwo]

Another ridiculously useful video for me and my job, thanks dude, I'm happy to be a patron for 1+ years, money well spent.

[ImperialLightandMagic]

Another great practical video, thanks. I used RS485 in kinda the reverse scenario of this on a project recently, and ended up with an arduino mega, with a dmx host shield very close to the very long strip end ( think I ended up around 15m of led) and signaled what it should do by sending dmx from a lighting desk. The mega listened for the dmx value and colour shifted accordingly

[EvaSaulnier-or]

Thanks for sharing and explaining so well !

[mfx]

Many people seem to think that Cat5 etc. twisted pair is good for standard "SPI" signals because that's what's used for data cabling but while it should be used for differential systems like Ethernet and RS485 (Cat5 is RS485 compliant) for standard single ended data it can make things worse due to the higher capacitance of the cable.

[AndrewBrown-xrpn]

I've just stumbled across your channel after wondering about eddy currents in my workplace's maglock door latches. You've got tons of videos relevant to personal projects I've worked on over the years (involving RGBW LEDs, generative AI, OpenSCAD, Arduino, ESP32, RasPi, MQTT, NodeRed...) It's a shame that <i>the algorithm</i> didn't recommend your channel sooner. Your videos are accessible for beginners while still being able to hold my attention for any little bits of knowledge I mightn't have noticed in my own experience on my own projects. Keep up the great work. Cheers!

[ZenHulk]

Thank you, i was going in the wrong direction. So i wasn't using an esp32, but i will now and i was not using a capacitor, never came up. That was a very informative video and now I'll get on the right track i felt like i was in class, Cheetos on my keyboard and the only sound was my labradoodle snoring, was like 1994 in Engineering school minus dog. Ok i'm just starting over after i find the capacitor box.

[jaimeestrella]

there is no such a thing like programmable LED, you program a LED driver NOT a LED