Lights, Holiday and Electronics


Earlier in the year Christian and element14 sent me the kit for the IoT Xmas Lights.

I was unable to enter in the challenge due to other commitments, so when I was offered the kit I promised to add something later.




I have an idea for the lights, and require to source some High Power LED's which the Infineon Shield can drive.

Most of the existing strings are already voltage controlled (just stick them across 12 v and they are happy).

There have been some great uses, but mine will be for anytime ... providing I can sort out the LED's I want and mount them properly.

Since the intention is for outdoor use, the proper enclosure is part of the design requirement.




One of the neat ideas to come out of the Challenge was the IoT link that Jan and Frederick came up with.

[Christmas Wreath of Things] Internet of Holiday Lights: part 10 - Secret IoT Team Up

[Christmas Tree] Internet of Holiday Lights - Special Feature

They extended the invitation to anyone else

Internet of Holiday Lights: Join the secret IoT Service - open for all

I was able to join in with a few lines of code, and an ethernet plug, and while it is a simple task to light a LED or LED's, it is a waste of the Arduino YUN to just do that.

I plan to use the YUN at a central point and send the data over a RF link to an micro arduino, that will drive the display.

The YUN will also interface to the Lights and allow remote control using a wireless device from my home network.





Some time ago Shabaz produced a fantastic map showing where challengers were situated.

He did it for In The Air and again for Forget Me Not.


I thought that lighting up the location when the person is online would be a great idea.



A simple print onto A4 later, and the penny struck ... some countries are not very large ... PLUS there are two people in one small country (ignoring the wives, children, cats and minions).


Hence a 5mm RGB or NeoPixel was just not going to work.

Time for another plan.




Fibre Optic

Everyone knows this is the stuff they send the internet down. 


     Photo source

Well yes that is true, but those tend to be glass fibres and are a fixed size.


Wikipedia has a good summary of most uses here.

Optical fiber - Wikipedia, the free encyclopedia


They can be used to illuminate sensitive subjects, since they don't conduct the heat, UV or Infra red and their small size makes them very effective.

Low cost LED technology may have displaced this use in many applications.


Some people may know that fibre optics were used on some older automobiles to show the various lights were working.

For the 1968-71 Chevrolet Corvette they ran from a fitting in the light through the wiring loom to the dash and were probably a salesman's delight at the time.

Corvette questions | stevelinden


I've used Fibre Optics for Lighting effects in three of our Casino's, and some other locations.

We used 'End Glow' fibres to light up square blocks of plastic, or a device that looked like a normal light bulb. There was fascination amongst the builders when these 'light bulbs' changed colour.

We also did a few Starfield simulations complete with 2-3m long shooting stars. (that is a whole other story)


The fibre optic generally used for lighting effects is solid plastic with a coating on the outside, and comes in a range of sizes from 0.75mm to 12mm diameter.

The advantage of the plastic means you can apply heat to the end, which creates a dome or lens shape, and of course you can glue/epoxy it.


If I use fibre optics then I have the means to transmit the light to a very small hole in a very small country.



What colour should I use.

I decided that just having a LED that was ON or OFF, was not going to suffice.

An RGB or even better a NeoPixel LED was the better option.


I chose to use some 5mm diffused NeoPixels that I purchased locally from Hadley at Nicegear (

I'll simply attach the fibre onto the top with expoxy or some other method that I'll finalise later in the hardware build.


How to Light them.

As I said earlier using the Arduino YUN to drive some LED's is a bit of a waste, and with the map fitted to a deep A4 Picture frame, I might not have room.

Instead I'm going to send the data via RF from the YUN to a micro Arduino mounted inside the picture frame.

This also allows for different powering options, so it can be fitted anywhere.



Eric Tsai provided us with some very informative posts about sending data using RFM69 Transceiver modules.

Uber Multi Wireless Sensor - smoke, gas, flame, dog barking, PIR movement, light - sensor


I used this technique to send Hot Water data back to OpenHAB in the Forget Me Not challenge last year.



Data to send

As it stands there are 4 participants in this secret IoT service.

I decided on three different states

Online (Green)

Last 24hrs (Red)

Unknown (Blue)


This could be achived with a single 8 bit number ... BUT what happens if someone else joins.


During the Forget Me Not challenge, the EnOcean modules were solar powered and worked with indoor lighting as low as 100 lux.

In order to work, they needed to conserve the data transmission so it was sent efficently.

For my purpose I have power, but the display could be battery powered (I haven't decided).

If I simply send any change of state, and then send the state every 5 or 10 mins, the RF transmissions will be minimal.

Once the receiver is awake, it only takes a few seconds to process and send the information to the Neopixels, and it can go back to sleep, where it will be saving battery life.

SO I can send more than a single byte of data.

This also means I could use the YUN for other indication ideas ....

Now that I've formulated the overall concept, and decided on a few of the particulars, its time to put the bits together.

In my next blog, I hope to sort out the RF data transfer protocol and drive the NeoPixels.

I should have sorted out the picture frame, and decided how to get two fibres into this country.