NeckLight V2 : Glow-In-The-Dark Necklaces With Shapes, Colors and LIGHTS

Hi everyone,

After the first Instructables: NeckLight I posted which was a great success for me, I choose to make the V2 of it.

The idea behind this V2 is to correct some mistake of the V1 and to have more visual option.

In this Instructables I will explain how I made my 6 necklaces and how you can make new ones.

What is NeckLight ? The idea being NeckLight is to use the PCB manufacturing process to make it into something aesthetic and innovative. As the title says, NeckLight is a glow-in-the-dark necklace operating with a simple battery + led circuit.

The design of the six necklaces is inspired by gemstone cutouts :

• DIAMOND : White PCB & 8 White LED
• RUBY : Red PCB & 10 Red LED
• AMBER : Yellow PCB & 8 Yellow LED
• ONYX : Black PCB & 6 Yellow-Green LED
• SAPPHIRE : Blue PCB & 8 Blue LED
• EMERALD : Green PCB & 8 Green LED

How does NeckLight work ? Just insert a flat cell CR2032 and the necklace start to glow.

Why 6 designs ? Because my goal was to use all the colors made available by JLCPCB.

To make one NeckLight you will need :

• 1x Custom PCB made by JLCPCB (check steps below for GERBER files)
• 1x SMD 0603 resistor (It's better to have the resistor sample book to be able to adjust the brightness)
• 1x CR2032 battery holder
• 1x CR2032 battery
• 6-10x SMD1206 LED (Choose your color)
• 1 meter of black string

Required tools :

• A soldering iron
• Tweezers
• Soldering tin

Optional tools :

• A multimeter
• A 3rd hand
• An old toothbrush and some Isopropylic Alcohol to clean the PCB

The first step if you want to make a new kind of necklace is to design it.

I use the software Fusion360 to create the .DXF who is import in EasyEDA.

Here are few tips (All the informations are on the two pictures );

• The hole to insert the rope is a 5mm half circle
• A great size for a 1206 LED is 3.5x2mm
• Be sure that the battery holder fits (picture 2)
• Add a filet of 0.3mm on all angles

What are the constraints ?

• The GND must be in the middle of the necklace
• All the LED GND must be facing the middle
• The battery holder determine the minimum width of the pendant (23.5mm)

As I say before, I ordered the 6 different pcb on JLCPCB with the caracteristic below :

• PCB Thickness : 1.6mm
• Surface Finish : HASL(with lead)
• Copper Weight : 1 oz
• Remove Order Number : Specify a location

To solder one pendant is pretty straightforward, just follow the 3 steps below :

• Solder the battery holder
• Solder the resistor
• Solder the LED (check the direction carefully)

The resistor value change between each necklace, to know more details go to the further steps.

Make the necklace is pretty simple just follow this tutorial, a length of 1 meter of string seems good.

Characteristics :

• 8 green LED
• Resistor of 390 Ohm
• Current consumption 1.89mAh
• Autonomy of 200/1.89 = 106 hours with one CR2032 cell
• Size : 28mm height x 24mm width

Files :

• NeckLight_V2_Emerald_GERBER.rar -> Import it on JLCPCB or other to order PCB

• NeckLight_V2_Emerald_PCB.rar -> Import it on EasyEDA or other to modify the PCB

Characteristics :

• 10 red LED
• Resistor of 200 Ohm
• Current consumption 6.06mAh
• Autonomy of 200/6.06 = 33 hours with one CR2032 cell
• Size : 43mm height x 24mm width

Files :

• NeckLight_V2_Ruby_GERBER.rar -> Import it on JLCPCB or other to order PCB

• NeckLight_V2_Ruby_PCB.rar -> Import it on EasyEDA or other to modify the PCB

Characteristics :

• 8 blue LED
• Resistor of 200 Ohm
• Current consumption 1.58mAh
• Autonomy of 200/1.58 = 127 hours with one CR2032 cell
• Size : 45mm height x 25mm width

Files :

• NeckLight_V2_Sapphire_GERBER.rar -> Import it on JLCPCB or other to order PCB

• NeckLight_V2_Sapphire_PCB.rar -> Import it on EasyEDA or other to modify the PCB

Characteristics :

• 8 yellow-green LED
• Resistor of 100 Ohm
• Current consumption 8.64mAh
• Autonomy of 200/8.64 = 23 hours with one CR2032 cell
• Size : 32mm height x 24mm width

Files :

• NeckLight_V2_Onyx_GERBER.rar -> Import it on JLCPCB or other to order PCB

• NeckLight_V2_Onyx_PCB.rar -> Import it on EasyEDA or other to modify the PCB

Characteristics :

• 8 white LED
• Resistor of 270 Ohm
• Current consumption 1,59mAh
• Autonomy of 200/1.89 = 126 hours with one CR2032 cell
• Size : 31mm height x 39mm width

Files :

• NeckLight_V2_Diamond_GERBER.rar -> Import it on JLCPCB or other to order PCB

• NeckLight_V2_Diamond_PCB.rar -> Import it on EasyEDA or other to modify the PCB

Characteristics :

• 8 yellow LED
• Resistor of 100 Ohm
• Current consumption 8.96mAh
• Autonomy of 200/8.96 = 22 hours with one CR2032 cell
• Size : 30mm height x 26mm width

Files :

• NeckLight_V2_Amber_GERBER.rar -> Import it on JLCPCB or other to order PCB

• NeckLight_V2_Amber_PCB.rar -> Import it on EasyEDA or other to modify the PCB

Now the last steps before going to a party is to take your NeckLight insert a battery and start enjoying ^^.

In my case this necklace will make a great Christmas gifts for my family.

If you want to support me or if you want to have a necklace without making it, I sell the 6 designs on my ETSY page.

If you make other design, please comment with a picture of your unique design I would love to see it.

Have a great day !