Wearable Mini Voltage Meter - Debugging Tool

The wearable (or rather attachable) voltage meter is a measurement device that can be added to any fabric or metal surface. A regular multimeter can be difficult to use while your wearable or e-textile is on your body or in movement, this device solves that issue by being a lightweight and dependable voltage meter that can be easily added to most projects. The meter has a magnet on the back so that when you want to attach it to a piece of fabric, you need to use another magnet or a metallic object to secure it.

This material is based upon work supported by the National Science Foundation under Award #1742081. The project page can be found here.

This project was developed in the Craft Tech Lab and ATLAS Institute at The University of Colorado, Boulder.

If you want to keep up with my work, or just toss around ideas, please do so on my Twitter: @4Eyes6Senses. Thanks!

Step 1: Materials

1x Custom PCB - while this project can be done with a regular protoboard, if you want to order the custom PCB you need to upload the "VM_GBR.zip" to any PCB manufacturer. I used JLCPCB and it costs about $4 for 5 boards.

2x Different color paracord

2x Thin silicone jumper wire

2x Alligator clamps

1x Heat shrink tubing (3.5mm)

1x lipo battery (35mm x 25mm)

1x three-wire voltmeter

1x Small switch

1x JST 2-pin connector

Step 2: Print Housing

I suggest printing the housing and needle grip first as they are essential for the following steps and take longer to print. You can also create the logic probe without the housing, but you will need to skip some of the steps later on.

Step 3: Create Clips

- Cut a piece of paracord so that it is about 8 inches, and remove the inner white nylon insert (Figure 1).

- Take the two silicon wires and strip them (Figure 2).

- Carefully thread the silicon wires through the inside of the paracord (Figure 3).

- Crimp the alligator clips the exposed sections of the wires (make sure the wire is making good contact with the alligator clips) (Figure 4).

- Place the 3mm heat shrink tube so that it is covering both the paracord and alligator clips. Then shrink the tubing (Figure 5).

- You should now have two clips that look similar to figure 6.

Step 4: Populate PCB

JP1: 2-pin JST

JP2: Three-wire voltmeter - I completely strip the voltmeter's wires then solder them to the PCB (Figure 2). I also add some hot glue to the bottom of the meter to hold it in place

S1: Small Switch.

First hole above S1: This via is for the common ground, solder one of your clips to it and secure the paracord with hot glue.

Second hole above S1: This via is for measurement, solder one of your clips to it and secure the paracord with hot glue.

- Your PCB should like similar to figure 3.

Step 5: Attach Housing

- Place the completed PCB in the main housing (Figure 1).

- For the backing, glue a 12mm diameter magnet to the imprint (Figure 2).

- Carefully hot glue the backing to the main housing (Figure 3).

Step 6: Done!

You now have your very own wearable voltmeter! Happy debugging!