ic Handbag Project

workshops showcase starter kit coding & technical
earlier steps
Step 3. Connect the LED lights (NeoPixels)

We like to keep the Gemma and the battery as a detachable unit so that we can use them in multiple projects. To achieve that we always 'wire' the LED lights back to three 'snaps' that are in a convenient place. Here they are located near to where the flap of the bag starts (about midway up the picture).

The LEDs are at the top of the picture, on the other side of the leather.

1. The two tracks running in parallel up the righthand side carry the power.

2. The track running up the middle sends signals to the LEDs. It goes to the first LED only. Separate connections join LED 1 and 2, and LED 2 and 3.

sewing inside electronic handbag
The diagram below shows what we are trying to achieve. For your first project you may wish to connect the Gemma directly - but doing it this way makes all of your future projects a lot quicker. It also makes is easier to stay safe, by removing the Gemma and its batteries when not in use to amaze (or amuse) your friends.

diagram of how to connect the Neopixels and gemma in an electronic handbag

Note that you need to put the sewable snaps on the back of the material the Gemma is sewn to, so that the Gemma is still easy to get to once snapped into place. Once you try this for yourself you'll also realise that it needs careful planning to avoid the conducting threads from touching - which could cause lots of problems (including in the extreme, burns to your bag and even a danger of fire). DO NOT LEAVE BATTERIES/POWER CONNECTED WHEN YOU ARE NOT THERE.

You do not need a USB cable connected to have everything work. It has two uses that we will explain more later, but in summary, the USB cable can be a good temp power source when testing, and it is also essential if you wish to upload code to the Gemma when you get to the stage that you want to make your own patterns of lights.

The rather unattractive item on the right was an early attempt on our part to create a detachable Gemma.

Luckily it is out of sight whenever we deploy it on a project so we don't have to worry too much.

Those of you will great sewing skills will want to make something more attractive, maybe with a little pocket to hold the battery etc.

what happens when poor sewing skills meet tech

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