Ever since I saw the Draper 2.0 by ChrisSmolinksi on Instructables I've wanted to make something similar. Well, my chance finally came when my wife and I were invited to an MFA Gala in Boston with 'Creative Black Tie' as the dress code. That was the go ahead I needed to create my own version of LED pocket square.

My goals for this pocket square were to create something that had an easy to reach on/off switch, a custom circuit board, programmable/addressable LEDs, and adjustable pocket depth. All code, Eagle files, and links to components are attached or linked, but if there is something I've missed please let me know in the comments. Now let's get started.

Materials

1x Adafruit Pushbutton Power Switch Breakout
1x Adafruit MetroMini
1x Adafruit Powerboost 1000 Charger
1x LiPo battery
1x 8x1 Neopixel Stick
1x Single Sided Copper PCB (to fit into Bantam Tools PCB Mill)
Solder
Breadboard
Jumper Wires
48x Header Pins
2x 2.0M x 10 screw (OPTIONAL)
5x 2.0M nut (OPTIONAL)
Double sided tape
1x Tuxedo and Pocket Square

Tools

Soldering Iron
Bantam Tools PCB Mill
Wire Strippers
Felt Point Pen
Drill with

Software

Step 1: Test Your Circuit

The circuit introduces power via a LiPo battery to the Powerboost module. This in turn goes to the Soft Power Switch, which allows current to flow to the LED stick and MetroMini when pressed, and stops the flow of current when pressed again. I began the design by testing it on a breadboard. Even though the final .brd file is provided, I highly recommend you complete this step before going forward with cutting a PCB board and soldering components together. The schematic for the circuit, I accidentally left out the battery, which connects to the Powerboost module. You can follow the schematic and the breadboard images in this step, but I will also write out how to connect the circuit for those who have not worked with circuits much (myself included!)

I'm assuming you are familiar with how a breadboard works here, if not, there are plenty of helpful links on the internet. Use jumpers to make the following connections.

Connect the 5V pin on the Powerboost connects to Positive Rail, and the GND pin to the Negative Rail.
Next, connect the Vin and GND on the Push Button the the Positive and Negative rails.
On the opposite side of the button, connect Vout to the 5V pin on the Metro Mini.
Connect the GND pin on the MetroMini to the Negative Rail.
Use a second jumper in the same row as the 5V pin on the MetroMini and connect it to the 5V pin on the LED stick.
Connect the GND on the LED stick to the Negative Rail. Lastly, connect Pin 6 on the MetroMini to the Din on the Led Stick

Use a MicroUSB and connect the MetroMini to the Arduino IDE. If you are unsure how to use the Arduino IDE, there are plenty of tutorials out there on the internets. When programming you can select Arduino Uno as your board. Additionally, there is plenty of Neopixel code out there, so you do not have to write code from scratch. Here is a link to the code used in the videos found in this 'ible. (Note - the video in the intro section used a Knight Rider style code, however, the linked code files is a fade. I used this fade code in the end and you can see video of it in the last section of this instructable).

Upload your code and make sure everything is working as expected.

Step 2: Cut Your PCB

I recognize that not everybody will have access to a PCB milling machine. This project can certainly be done soldering components to a prototyping board, howoever, my goal was to create an easily reproducible PCB, and to learn how to use Eagle in the process. You can also send .brd files created in Eagle off to be manufactured by somebody else. Check out this list from Ladyada for more info on that. I've linked my .brd file to this instructable, feel free to use and modify as you wish. I will briefly go about how to cut this if you do happen to have a Bantam Tools PCB Mill.

If using the Autorouter in Eagle, be sure you are routing the BOTTOM of the board. Additionally, make sure you have the Bantam Tools DRC file for a 1/32" drill bit. You can download it here. When transferring from Eagle to the Bantam Tools software the board should look mirrored because we are cutting the bottom, which is the copper side of the board. When happy with your board design in Eagle you can simply save the .brd file and open it in the Bantam Tools software. Be sure you have the correct drill bit set and all traces, holes, and outlines, are selected in menu on the right hand side of the screen. All the other settings on the right hand side of the screen should look similar to the image above.

Step 3: Add Screw Holes (OPTIONAL)

Place your components onto the front face of the PCB board as in the image above. I decided to add a 2.0M screw and nut to the Powerboost module and the LED stick to relive stress on the solder joints. With the components on the board, mark the bottom right screw hole with a felt tip pen. Additionally, mark the far right hole on the LED stick (farthese from the solder joint). Drill through the board in those two spots. Put a screw through the screw hole on the Powerboost, then tighten a nut to it before place it on the PCB. The nut will act as a standoff for the Powerboost module. Use a second nut to secure the screw from the underside of the PCB board. I used two nuts as standoffs for the LED stick, but one is probably enough. Now we are ready to solder. Solder the pins on the back side, copper side. I only solder the pins connected to vias, which helps limit chances of solder creating an unwanted grounding connection, and just seems more efficient to me. You may be wondering why the image of the back of the PCB has a green wire soldered into it. Well, mistakes happen. My initial schemtic design in Eagle had a mistake which tranlated to the .brd file. I was able to correct the issue by adding this green wire. I've since gone back and updated the schematic and .brd files in Eagle, and the correct files are attached to this Instructable. I'll probably go ahead and cut a new board in the near future, but I did not feel like wasting boards with such an easy fix available.

Step 4: Time to Solder

Solder the pins on the back side, copper side. I only solder the pins connected to vias, which helps limit chances of solder creating an unwanted grounding connection, and just seems more efficient to me. You may be wondering why the image of the back of the PCB has a green wire soldered into it. Well, mistakes happen. My initial schemtic design in Eagle had a mistake which tranlated to the .brd file. I was able to correct the issue by adding this green wire. I've since gone back and updated the schematic and .brd files in Eagle, and the correct files are attached to this Instructable. I'll probably go ahead and cut a new board in the near future, but I did not feel like wasting boards with such an easy fix available.

When you are done soldering, attach the battery to the board next to the Powerboost module using double sided tape. Plug the battery cable into the Powerboost module, the blue

Step 5: Fire It Up!

When you are done soldering, attach the battery to the board next to the Powerboost module using double sided tape. Plug the battery cable into the Powerboost module, you should see a blue LED turn on. Press the power button, which has a red led below it turn on when pressed. The LED stick should start working at this point. Push the button again and the LED stick should turn off. The blue LED on the Powerboost module will remain on while a battery is connected.

By plugging a micro USB into the PowerBoost module you can charge the battery. Use the MetroMini to upload code to get the LEDs to operate as you desire. I've tried several different types of code with this project. My initial outing with it used the code that it attached to this 'ible, which is a sublte fade in and out, almost like breathing. The LEDS get bright, fade, and repeat - shown in the videos in this section. In the Introduction section, however, I had started off with a more Knight Rider effect. Questions? Leave them in the comments.