Housing and sensor glove

Housing and wrist strap

The circuit housing and wrist-strap transform the circuit into a wearable contraption.

Tools

• Craft knife
• Cutting board
• Steel ruler
• Glue gun
• Needle and pins
• Attachment and cutting tools for snap fasteners (usually supplied with snap fastener set)

Materials

• A4 sheet of firm or flexible plastic (e.g. a disused plastic folder)
• 4 sets of heavy duty snap fasteners
• High strength sticky back velcro
• Square of non-conductive foam padding (7.5 x 3.5cm, approx 1cm thickness)
• Thread
• Two long pieces of elastic, approx 28 cm length, 2.5cm width
• Two smaller pieces of elastic, approx 7cm length, 2.5cm width
• 4 D-ring buckles

You also need the assembled circuit, with the Teensy and Ultimate-GPS breakout mounted.

Steps

1. Cut out the sensor housing from the following template, attaching snaps, folding and gluing as instructed.

Download template as pdf

2. Stitch the sensor circuit to the foam padding. On the other side, attach a strip of sticky-back velcro. Attach the opposite velcro piece to the flat inner area of the sensor housing, so the sensor can attach snugly within.
3. Take each strip of elastic, and stitch a small seam at one end.

4. For each long strip of elastic, pull the other end of the elastic around the flat edge of two D-ring buckles, and stitch it approximately 4cm in, which secures the buckles.
5. Attach the two remaining snap fasteners to each of the buckles, about 6.5cm from the D-ring buckles.
6. Fold the edges of the small pieces of elastic apart 0.5cm in, and stitch them to the long piece of elastic - with one seam stitched about 2.5cm from the snap fastener, and the other about 6.5cm from the snap fastener. This creates a support for the USB battery - so adjust if your battery is a different size.
7. Attach the two straps to the sensor housing using the snap fasteners.

Sensor Glove

This glove measures the conductivity of the skin between the index and middle finger, allow the sensor to take a Galvanic Skin Response reading.

Tools

• Scissors
• Needle and pins
• Crimping tool
• Wire cutter
• Wire stripper

Materials

• Gloves (e.g. gardening gloves)
• Velcro (2.5cm width strips)
• Thread
• Elastic (9cm length x 2.5cm width)
• Strippable stranded write
• Copper tape
• Insulation tape
• Strippable stranded wire
• 2-pin male JST connector

Steps

1. Cut off the index and middle finger of the glove, leaving about 5cm of the finger. You can do this for all the fingers and thumb if your prefer.
2. Make a 5cm cut the remaining tube of the index and middle finger on the topside of the glove. Fold over 2cm, and stitch so this is secure. Overstitch the rough edges of the cut so it doesn’t split.
3. Cut two 38cm pieces of wire. Strip 5cm of each wire.
4. Cut a strip of copper tape – the length should be the circumference of one finger, with 2cm width.
5. Place the lower exposed part of one of the wires against the folded part of the index finger. Stick this part of the wire down with the copper tape, but do not entirely push down the tape. Wrap the wire over the copper tape, so the wires go over the middle of the copper tape (meaning they will wrap over the part of the copper tape that will contact the middle finger). Tightly tuck the wires under the tape and fasten.
6. Repeat 4 and 5 for the middle finger.
7. Stitch an elastic strip to the outer edge of the index finger tube so it can wrap around the finger. Do the same for the middle finger. It is best to do this at least 2cm in, so it doesn’t pull off.
8. Stitch the soft side of a velcro strip around the finger tube of the index and middle finger respectively, so it goes all the way around.
9. Stitch a seam into the loose end of each elastic strip. Stitch a hooked velcro strip into the whole inner length of each piece of elastic. This will allow it to wrap round to tighten the sensor.
10. Create a stitch-loop near the wrist to thread the two wires through. Join them with a piece of insulation tape on the other side.
11. Crimp the wires, and fasten them into the 2-pin male JST connector.

Sensor Palm Strap

The palm strap works on similar principles to the sensor glove, reading the conductivity of the skin between two points on the palm. This is a good alternative sensor, as it is useable by people with different hand sizes.

Tools

• Scissors
• Needle and pins
• Crimping tool
• Wire cutter
• Wire stripper

Materials

• Copper tape
• Thread
• Inside padding material
• Elastic strip (approx 38cm length, 2.5cm width)
• 2 D-ring buckles
• Padding material (this can be cardboard, foam, wrapped up gaffer tape etc)

Steps

1. Shape the padding into a small, roughly teardrop shape, approximately 2.5 (width) x 1.5 (length) x 1cm (thickness). Wrap a layer of copper tape around it.
2. Cut two pieces of the threaded wire, to be approx 35cm in length. Strip 5cm of the coating of the wire. Wrap the threaded wire tightly against each copper coated teardrop, and secure it with a small piece of copper tape at the back.
3. Stitch each sensor onto the elastic. They should be close enough together so both sensors can touch a person’s palm at the same time, but far away enough that the sensors will not touch each other (at least 2 cm)
4. Stitch a small amount of the elastic so it sticks up between the sensors, to stop them touching.
5. Stitch up one end of the elastic to make a tidy seam.
6. Pull the other end of the elastic around the flat edge of both D-ring buckles, and stitch it approximately 4cm in, which secures the buckles.
7. Strip the other end of the wires. Crimp them and insert them into the JST connector.
8. Wear it by placing the copper sensors against the palm, and fastening it round the back of the hand using the D-links.

Assembling the sensor

Components

• The sensor circuit in the circuit housing.
• Either the glove or the palm strap.
• A small, narrow USB battery.
• A short micro-USB to USB cable.

Steps

1. Put the battery through the two supports on the wrist strap.
2. Put on the glove or the palm strap.
3. Attach the sensor housing to your wrist using the wrist strips. The female JST connector should face forward towards the hand, the micro-USB board of the Teensy board should face backwards.
4. Connect the glove or palm strap to the sensor circuit using the JST connectors.
5. Connect the battery to the Teensy using the USB cable. The sensor should now boot and run.