TwinkleTie

Arduino code for runnng an RGB LED light show on a holiday necktie remote controlled via bluetooth. TL/DR: Rudolph with your tie so bright, turn that thing down before you harm someone's retina.

Demonstration

-Short demo of overall functionality and basic parts:

-Overview of the LED Patterns:

-Stranger Lights Pattern:

Schematic

This schematic shows an older version that used 2 strips but the concept is the same. The latest iteration uses just 1 LED strip.

Parts List:

• LED strip. 1m, 144LEDS. See notes below on differences and choosing. The video demo shows a generic brand strip without waterproofing.
  • first choice: generic brand WS2812 144/m strip - with adhesive
  • alternate: Adafruit NeoPixel 144/m strip - no adhesive
  • alternate: Adafruit NeoPixel 144/m mini skinny strip - no adhesive
• Microcontroller Adafruit Feather M0 Bluefruit LE
  • Arduino compatible
  • Fast, plenty of memory, lots of pins
  • Builtin bluetooth
  • Builtin connector for battery
  • Recharges battery (slowly) when USB is connected
• Battery 2500mah 3.7v lion battery
• Ridiculous necktie, bowtie, suspenders, hat ...
• (optional) Faster USB lipo charger

Notes

• LED strip waterproof rating and sticky tape backing:
  • IP30 rating means not waterproof. these usually come with a peel and stick backing
  • IP65 rating means waterproof to low pressure spray. These strips usually have a slightly rigid, curved, crystal clear silicone coating on one side and a peel and stick backing
  • IP67 rating means highly waterproof. These strips are usually inside a flexible rectangular silicone case that is not perfectly clear. This form of LED strip does not offer a peel and stick backing. Mounting is usually done with plastic brackets. I have not yet tried to build a tie with an IP67 strip and not sure how mounting would work. Maybe sew it to the tie?
• Microcontroller logic voltage vs LED logic voltage vs LED illumination voltage:
  • Logic voltage on microcontrollers is available in 5V and 3V formats
  • Logic voltage on addressable LEDs (WS2811 and WS2812) is 5v
  • Illumination voltage on addressable LEDS is 5V for this project but 12V is also available
  • A controller board with 5V logic levels is a sure bet when driving these LEDs but in recent years I have had very good results with 3V controllers directly connected to short LED strips
  • In this project I am using a 3V controller and driving the illumination with only 3.7V with great results
  • Having the illumination voltage just 0.7v above the driving voltage of 3V actually makes it more reliable and there is no noticeable sacrifice in brightness from using a driving that is 1.3V less than usual
• Construction tips:
  • The overall durability of a necktie with an LED strip stuck onto it is fairly low. I leave the knot permanently tied and loosen it just enough to pull over my head
  • Use something like a zip tie to anchor the LED control wires firmly to the controller board so the solder joints are not stressed and broken from normal use of the tie
  • Consider IP65 as more likely to survive stains!
  • If the weight of the LED strips causes the tie to lose its shape, you can insert a semi-rigid material such as leather inside of the tie to help retain a nice shape
  • In general, don't hesitate to remove threads holding the back of the tie together and re-sew after parts are in place. None of that will be visible from the front.
  • If you have to solder directly onto the LED strip, the joint can be fragile so it is very helpful to reinforce the solder locations with epoxy to provide durability
  • Best not to solder header pins onto the controller to keep the end result as flat as possible