LEDs: 4 and GND

Vibration: 2 and GND

Piezo: 0(-) 1(+)


LiPoly backpack:

5v to USB+

G to GND



LEDs: 0(-) 1(+)

Vibration: 2 and GND

Piezo: 0 (-) 1 (+)


LiPoly backpack

5v to Vout

G to GND

BAT to 3vo

This guide was written for the Trinket Mini 5v board. The pins used are different for the Trinket M0 (see the second diagram). We recommend the Trinket M0 as it is easier to use and is more compatible with modern computers!

Trinket Mini 5v Circuit Diagram

Trinket M0 Circuit Diagram

The images below depict the Trinket 5v configuration being soldered and assembled. Note the pin changes for the Trinket M0 in the circuit diagram above when soldering.

Two connections will be made on the back of the Trinket, using one of the pads for the optional JST connector.

Measure Wires

Lay the LiPoly backpack on top of the Trinket and cut each wire so that they are just long enough reach the through-holes on the Trinket.

Prepare LiPoly backpack

Use a filing tool to remove the trace to the battery output line to enable use with a slide switch.

Solder LiPoly wires

Add a slide switch to each pin of the battery output line. Tin the pins for the LiPoly backpack and add the wires that will connect it to the Trinket.

Prepare Vibration sensor

Bend the thicker pin of the vibration sensor so that it curves level to the outer cylinder.

Align Vibration sensor to Trinket

Use a small amount of tac to hold the vibration sensor in place while aligning the pins to the pads on the back of the Trinket.

Vibration sensor thinner pin

Bend back the thinner pin so that it reaches into pin #2.

LiPoly backpack wires

Use tweezers to help align each wire into the Trinket through-holes.

LiPoly ground

Share the ground with the vibration sensor on the back pad of the Trinket.

This makes it easier to solder the LED wires on top of the Trinket.

(Photo shows a single LED…later it was decided that two LEDs in parallel worked better. See diagram at the top of this page for wiring. Later photos show placement of two LEDs.)

Solder LEDs

Measure the length needed to fully diffuse the insde of the case. LEDs have a specific polarity…+ should go to pin #4, – should go to GND. Two should be used in parallel (see diagram at the top of this page)…it should be possible to fit two wires into each hole on the Trinket.

Trinket tac

Use a small amount of tac to help secure the LiPoly backpack to the top of the Trinket.

Light pollution

Use strips of black tape to help clear the enclosure of any red or green lights from the LiPoly and Trinket LEDs.

Don't solder the piezo to the Trinket until the wires are threaded through the back of the enclosure!

Mount Piezo 

Use two #2 56 phillip screws to mount the piezo to the back of the enclosure.

Coil piezo wires

To fit the circuit inside the tight space, coil the the piezo wires inside of the standoffs for the Trinket. 

Mount Trinket

Use one more #2 56 phillips screw to securly mount the Trinket to inside of the enclosure.

Insert slide switch

Use curved tipped tweezers to insert the slide switch into the two clips near the top.


Snap the diffsuer inside of the top cover part to help soften the light from the LEDs.

Position LEDs

Test that the diffustion is even by moving the two LEDs around in the enslosure until the lighting is even.

Wear it!

Attach a split ring and necklace to rock out with an audible bling to your step!

This guide was first published on Nov 20, 2014. It was last updated on Nov 20, 2014. This page (Assembly) was last updated on Jul 25, 2019.