Introduction: Silver RFID Ring
This guide will demonstrate how to make a silver ring that holds a glass RFID tag. It's the same kind folks get implanted in their hands to unlock things like door, computers, or vehicles. I'm not quite brave enough to get the implant but I do like making jewelry and wearing rings, so this solution is perfect for me.
I got these tiny glass ampoule tags and RFID reader from Trossen Robotics-- they are the daintiest tags I could find. Normally when mounting a stone on a ring, it's surrounded on at least one side by metal. I was worried the standard bezel would impact the tag readability, so I wanted to create a design that would allow the most possible open space around the tag. I prototyped the design without a tag, just to see how comfortable it was before scaling up to add the extra pieces and figure out the construction.
To make this project, you will need:
- Silver soldering and forming jewelry supplies as outlined in my Simple Silver Ring tutorial
- Hollow silver tubing
- Arduino or compatible with classic header pin layout, recommend 32u4 for application as keyboard input
- RFIDuino shield
- Extra small glass ampoule RFID tags
- Computer with Arduino software
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Step 1: Cut and Solder Silver Rings
I used a technique here to make multiple rings at once by winding the wire around my ring mandrel several times. then cutting through the rings with a saw, similar to the way you'd make jump rings.
This ring uses two silver rings connected by more silver wire. This project builds on my previous tutorial about making a simple silver ring with torch soldering, so head over there to make a couple rings about a half size too big and come back here when you've filed and sanded, but not polished, your rings.
Step 2: Solder Posts and Tubing to Each Ring
Cut and file two pieces of straight silver wire to just over the length of your RFID tag.
Using a base station with cross-locking tweezers to support your work, solder one wire to each of two rings, standing up straight while the ring is on the soldering surface (wire perpendicular to ring). Use medium solder so as to not remelt the ring's original solder joint. Alternatively, solder these wires away from the ring's first solder joint, and use hard solder. This has the advantage of giving you more flexibility in how you attach the bits of hollow tubing. Saw two very small sections of silver hollow tubing and file one end slightly with a round file. Solder these pieces to the rings at the same time as the wires mentioned above, or afterwards-- your choice. Use the next level of softness in solder for each stage of soldering, pickling and washing off in between.
Step 3: Assemble Halves Into a Whole
Use easy solder to connect the remaining uprights to their companion rings, aligning the tubing pieces with one another.
Step 4: Prepare Setting and Polish
Open up the setting a bit using a rotary tool and small round burr. The goal is to fit the RFID tag into the setting, far enough so it won't easily fall out. Test fit until this objective is achieved.
Next it's time to file, sand, and polish the ring. Take your time getting into all the nooks but be careful with the rotary tool and never put your finger through the ring at the same time as the rotary tool (protect yourself from getting caught/injured).
Step 5: Install RFID Tag
After polishing, thoroughly clean the silver ring and apply any finishing wax or tarnish retardant that you may want. Then install the RFID tag for the final time. You may need to gently hammer the settings together to pinch the tag.
I've worn my ring around town for a few weeks and the tag hasn't fallen out, but that doesn't mean it won't. So please don't make anything that relies mission-critical on this tag-- I'm expecting to have to replace it at some point.
Step 6: Use It!
To test out the ring, I'm using an RFID Arduino shield with a sample sketch that prints to the serial monitor. Next I think I'll try to get it working as a password helper using an Arduino that acts like a keyboard. Looking for more RFID project inspiration? Check out the comments on my Instagram post about this ring, and for postulations on the ring's affect on the readability of the tag, go check out the Hackaday comments.
Congratulations, you've made it to the end! If you enjoyed your experience, please share this guide with a friend. If you make this ring or something similar, I'd love to see it in the I Made It section below!
If you like this project, you may be interested in some of my others:
- Sheet Metal Jewelry Basics - Saw, File, Sand, & Polish
- Silver and Amber Ring
- Mash Up Arduino Code Samples
- Solar Engraving
- Workbench Storage Upgrade
- Wedding Portrait Embroidery