Laser Engraved QR & NFC WiFi Access Card

Quick, name the worst thing about having guests over to your house. Nope, it's not people touching your stuff or putting their disgusting feet on the cruelty-free, hand-stitched, Himalayan yak-leather ottoman. It's having to tell every single one of them the convoluted password to your WiFi so you all can happily ignore each other while browsing your twitter feeds to revel in the glow of other people with more interesting lives than yourselves.
Admittedly, that got a little cynical but if you've ever said something like "That's 'b4', the letter 'b', the number '4', no spaces, and all caps on ptarmigan." "No... No, p..t..a..r..m..i..g..a..n." "Yes, I know it's confusing grandma but writing me out of the will seems a little rash." then you know where I'm coming from. Luckily technology has provided a solution, actually two solutions, to this most dire of situations. We're talking about QR codes (Quick Response codes) and NFC (Near Field Communication).
By combining these technologies into a simple card or plaque, every smartphone toting guest, regardless of OS, will be able to easily sign themselves into the network.

P.S. Don't worry if you don't have access to a laser engraver. You can get the same functionality with a printer and some tape.

Materials

• Wood Blanks - Mine are 3/16" thick but anything down to 1/8" should work fine. The final size is 1.625" x 2.25" but you can scale as necessary. I got mine at a local craft store.
• NFC Tag - You can find these in consumer bulk (10+) at all the usual places (Amazon.com or eBay.com). Mine are these.
• Clear Paint (Optional) - Just something to protect it and make it look a little more "finished". Highly recommended for those using a laser engraver/burner.
• Wood Filler (Optional) - For filling in over the NFC tag.
• Instructables Sticker (Very Optional) - An aesthetic covering for the back and a deserved shout out for your favorite DIY website.

Tools

• Laser Engraver/Burner - I used a NEJE DK-8 Pro-5 provided by GearBest which is an inexpensive mini laser engraver. The small (3cmx3cm) cutting size means that some creative setups are necessary for bigger projects but it was very easy to get going and seems to be pretty precise for the cost.
• Saw - Anything to trim the blanks to size. A table or band saw probably are the best bet but anything, even a rotary tool, can get the job done.
• Rotary Tool - This is what I used to hollow the back but any way you can manage to get it done is perfectly acceptable.
• Sandpaper - A pretty obvious inclusion most any time you work with wood.
• Masking Tape - For protecting finished areas while working on others.
• QR Code Generator - There are plenty of free ones online.
• NFC-Enabled Android Device- All of this may be possible on iOS but I'm in no way qualified to state that as a fact.

There are a number of websites, and apps probably, that will work to generate your QR Code. I used THIS one and it worked fine but feel free to use your favorite, as long as generating WiFi credentials is among its functionality.
Once you choose a method then simply enter your SSID, password, and encryption type. Be sure to scan the generated code with a bar code scanner, I use THIS one, to verify that it works and if it does, save the code as an image and move on.

The NEJE engraver I used has its own software that accepts a single image as its input. This means I had to do a little manipulation before setting it on its marry way. For this I use Paint.NET, which is a good, free, and expandable, Photoshop alternative for mid level work.
The real limiting factor for the engraver is the small size, using images with resolutions of 512x512. To keep everything a readable size I had to break the face into two images and cut them in two separate sessions.
Using Paint.NET I shrunk the images and added text, making sure my orientation was correct for the engraver.

With the images ready it's time to light it up. Orient a wood blank, transmit the image, dawn your filtered glasses (safety first, remember this is a laser capable of sublimating wood), and let it burn.
Once the first image is done, re-position and repeat for the second image (of course if your engraver is bigger than mine this may not be necessary). Orienting for the second image can be a little tricky, even with the preview function on my machine, which traces the outer boundaries of the image, but as long as you're close it will look fine.

While the laser runs, get your NFC tag ready to go. If you have Android Marshmallow then you can use the built in WiFi manager to write the info to a tag. If you don't then you will need a third party app, like NFC Tools, to write it. You can see both methods in the video above or steps below.

Marshmallow

1. Open Settings... WiFi.
2. Long press on the network you want to save.
3. Select "Write to NFC Tag".
4. Enter the network password and confirm. Place your phone over a NFC Tag to write.

NFC Tools

1. Launch the app.
2. Go to Write... Add Record.
3. Scroll down and select "WiFi network".
4. Enter your networks information and confirm.
5. Select Write and place your phone over a NFC Tag.

With the engraving complete the next thing you'll want to do is use some clear paint to protect the images. This is technically an optional step but the engraving leaves some carbon build up that can smudge onto the surface of your wood. This is also why it's important to do this as the first step after engraving.
Once the paint is dry it's time to cut the large blank down to its final size using whatever means available. Be sure that you leave enough room for your NFC tag and be aware of which way your blade is running if you are using a powered saw of any type as to not ruin the front face (face up on table saws, face down on chop saws).
Use the sand paper to clean up any rough edges and consider rounding the corners a little for aesthetic and safety reasons. At this point I hit it all with another coat of paint just for good measure.

Now it is time to insert the NFC tag into the card. Mark out the perimeter of the tag on the back of the card on the same side that the NFC symbol is engraved. I used a rotary tool with a grinder bit to clear the area, which was ugly but worked. As long as you don't break through the face or an edge and the tag sits flush in the pocket then ugly is ok. We're going to cover it all up later anyways.

Once the pocket is cleared and cleaned the tag will need to be secured inside. Mine, and most I've encountered, come with a sticky backing so it's as easy as removing the film and sticking it in. If yours don't then simply apply some sort of general use glue.

The final few steps just get everything looking nice and presentable. Before starting I suggest covering your nice clean face (of the card, get that off of your nose john) with masking tape to protect it from scuffs and dust.

Use the wood filler to completely cover the tag and fill its hole. It doesn't matter if piling it up is the only way to get it to stay on because the next step is...

Sand the back until it is all flush, once the filler dries completely. Clean up the dust and then hit the back with some more of the clear paint to seal and protect. At this point you could be done but I took it one step further and trimmed an Instructables sticker to fit and slapped it on.

Uses

Obviously easing access to your home network is a given. Consider Putting one in a common area and in each guest bedroom. These would be especially handy for anyone who has a condo or house they rent on a short term basis (e.g. airbnb). I could see this also being helpful for small business owners or other such "public" WiFi access points. It's more secure than an open hotspot but doesn't actually revel the password to most casual users.

Where will, or would, you be using one? Are there other features I should have included? Feel free to post along with any other questions or comments and be sure to post photos if you make one, even if it uses an alternative method (I realize a laser engraver is not what you'd call a "common" household machine).

NEJE DK-8 Pro-5 500mW Laser Engraver

This was my first experience with laser engraving or cutting on a consumer level and I must say it's been mostly smooth. Obviously the first thing about this machine is it's very small, the engraving area is 3cm x 3cm, so you can't fit larger pieces in whole and larger images will need to be done in multiple sections. There is a neat feature that traces the bounding box for the image with the laser on low power which helps make alignment a little easier but it's not perfect. That said it worked straight from the box, is quick, seems precise, and looks to be well priced. It's a good little machine for getting into CNC or laser engraving and quite possibly could be upgraded to a larger form factor without a lot of the work of building one from the ground up.

Disclosure

The laser engraver used in this Instructable was provided by GearBest. Any opinions expressed in the proceeding tutorial are mine alone and have not been moderated in any way by GearBest or any of it's employees.