Of course! (You thought e-textiles is not political?)
Just a “quick” hack: (well in the end it will be 2-3 days of work anyway…)
From a discarded party dress, some steppermotor and a distance sensor, together with some flimsy 3D prints with the simple text “Je suis Charlie”. This experimental e-textile group joins in.
The dress from a friend in Bremen is having horizontal strips of fabric. Ideal for the purpose of this idea because these strips can be lifted. If the strips are lifted the backside of the strip is shown, and the text appears.
The hardware to do the lifting is a stepper motor, which is attached to the back. It has to be sturdy to lift all this fabric. A distance sensor is driving the interaction.
First the text on the 3D prints consisting of up to 3 layers of PLA: (they will be all bright yellow in the end result)
The top of the dress is made more smooth for the wire to run over it by a plastic covering, the yellow band is at the moment holding the motor at the back, will be replaced… (lot’s of details even in a quick hack).
All very simple, but for a few details…
The hardware is just hardware, it is not concerned about the world and won’t cooperate. Otherwise stated: if you have an idea thought out, and it has a nice purpose, this doesn’t mean that you (yourself) make the right decisions about the hardware and programming.
So although being politically involved we had to debug. Do you mention the debugging in this kind of posts?
———Skip this part if you are in politics only!————->
The setup was working when hooked up to the laptop for uploading the script. But running from an adaptor the distance sensor got mad and always fired the steppermotor.
Measuring voltage and current a strange thing was noticed: the current consumed by the motor was 0.1A when running, but after stopping it consumed .25A. So the stepper.h (default arduino script) had to be mended:
after “a step” in the function void Stepper::step(int steps_to_move) of the normal Arduino script “Stepper.h“, all the PIN’s must be set to LOW:
to reduce the current to normal levels after stopping. That this is not done in the scrit is surprising. It means that some of the coils in the steppermotor are left with a voltage, and since the coils have a low reistance, the current is high – and waisted!
But mending this first feature didn’t fix the weird behavior of the sensor. So we tried a capacitor over the Voltage from the adaptor. A capacitor of 470 microF solved the problem. Apparently this adaptor (see pictures) is not very stable.
Pictures of the distance sensor, stepper motor, capacitor which saved my day and the wicked adaptor: (all at the back of the dress on the dummy)
The script is a combination of a stepper motor example, combined with a “NewPing” distance sensor. If you are interested, you can download the script and play on:
For printing the flimsy 3D prints I was using a setup described here in Dutch:
This way of making relief printing will be described more in detail in another post.