Busy hands | Disquiet mind

Accelerometer data to RGB

Sat, 25 Jul 2020 09:16:01 GMT

The LilyPad Accelerometer (ADXL335). I've been trying to use this for over ten years. Turns out I've misunderstood what it measures for 10 years. I had partial success with just the x-axis using Leah Buechley's code, but it has since disappeared, so I can't even be sure what it did.

I was trying to do something else, and the numbers, very strangely kept coming out to an exact 100.0, which is very wrong. So I went back to make sure the accelerometer was giving me a full value range. Which it didn't seem to be, so I went researching and found this excellent tutorial.

Although the accelerometer gives you raw values between 0 and 1023 on an analog read, it actually measures gravity acting on it as it moves around in 3D space. Converting the raw to Gs is straight-forward;
long xAcceleration = map(xRawPinValue, 0, 1023, -3.0, 3.0);

To then turn this into a colour, simply, you could map the range onto -255 to +255 (the polarity demonstrating direction of change), and then reducing that to just value of change;

int xRed = map(xAcceleration, -3.0, 3.0, -255, 255);
int absoluteXRed = abs(xRed);

Do the same for the y and z. Write to RGB LED/pixel of your choice. (Warning; movement in video is quite sudden.)

( Short video )

Sorry for the rough prototype version, I dismantled the version I made up for parts to make my tiara.

Other than light-up gloves, this could be used for rough gesture control, but doesn't give me the kind of information I needed for the thing I was trying to do as is.

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SciHackDay project; Temperature reading face mask

Sun, 08 Mar 2020 21:48:56 GMT

Science Hack Day 2020 began as has become tradition, with tiny food. Excellent.

Tiny food
Photo by chebe

Then the introductions, the pitches, the socialising, before settling down to work on projects. I came into SciHackDay with three pre-existing projects to work on. But one brand new one, barely 12 hours old, just for SciHackDay.

With COVID-19 doing the rounds there has been a lot in the media about face mask shortages, of border guards checking people for fever, and of people doxing sick children because of the perception that they deserve to know.

So I wanted to make a face mask, that reads your body temperature, and displays it to the world, while you yourself can't see it, because it's not for your benefit.

( Details )

Wear with cynicism.
Photo by chebe

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RGB Colour-Mixing Hat

Sun, 13 Jan 2019 15:22:17 GMT

A long time ago I acquired a hat. Some time after that, still a long time ago, I added a blue LED strip to the band. Later again I replaced the silver ribbon with a black ribbon, removed the original hat band (cutting the glue off the hat), hot-glued a felt pocket to the inside to hold the battery, and cut a slit so the wires could pass through.

But single colour LEDs? Running off a 9 volt battery? Not good enough nowadays. Enamoured with potentiometers of late, I got the idea of doing a red-green-blue plus brightness mixing board. (Bonus points for not using radio, meaning it would remain functional at maker/hacker meetups where radio frequencies are often saturated.) I found myself in Makevember so I did up a quick breadboard prototype.

( images )

But once I had that done I wanted to add extra modes, controllable by pressing the push button a number of times. The first one I added was Rainbow Cycle (I'm using the Adafruit Neopixel library rather than FastLED here).

Rainbow pattern
Photo by chebe

( Videos )

Parts;
Hat
Adafruit Mini Skinny NeoPixel Digital RGB LED Strip, 60 LED/m
Adafruit Flora
Bakelite Perfboard
Potentiometers
10K ohm resistor
Momentary push button
Headers
Various jump leads
LiPo battery

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Colour Stealing+ Cyberpunk Headpiece

Sun, 02 Sep 2018 15:28:29 GMT

Somehow, while making my Colour Stealing Skirt, I got the idea that I would like a headpiece to go with it. I mean, it's for EMFcamp, so go big or stay home, right? (Not at all, but I wanted to so I made excuses.) I wandered down a path of cybergoth falls for a little, but wanted something a bit more cyberpunk, and what is more punk than outrageous mohawks? But I don't have a 3D printer, or laser cutter, or CNC. How was I going to get something strong enough to stand upright, but translucent enough to light up nicely? I had an idea in my head of circles, inspired by CDs and hair rollers, but nothing else. So I took myself on a tour of hardware shops and wandered aimlessly. Eventually I found these. They come in different diameters and different heights, but these seemed just right for me.

Plastic furniture leg/wheel coasters, or floor protectors
Photo by chebe

Next step; how do I affix these plastic circles to my head? I wandered around youtube until I found people who use garden wire (for trailing vines and such) to make frames for costume headpieces. The idea is to shape a double-sided U-shape (one for each side of the head) out of the wire. You make the join with duct tape. I added extra supports to the top, by bending the ends to sit along existing wires, and duct tape them together.

Wire frame base
Photo by chebe

Then I continued in the same way down the back of my head. Aiming for a secure fit. I also wrapped the wire with ribbon (secured with super glue), not just to make it nicer, but because the duct tape glue was coming undone and the ribbon keeps pressure on all the joins.

( Many details )

Wear
Photo by Jeffrey_Roe

Parts;
Galvanised Coated Garden Wire, 2mm / 12 Gauge / 5/64"
Ribbon
62mm plastic furniture leg/wheel coasters (floor protectors)
Organza scraps
Wide crinoline tubing

Potentiometer
Adafruit Flora
Adafruit Neopixel strand
3-pin JST SM Plug + Receptacle Cable Set
Adafruit Colour Sensor
LilyPad Button Board
SparkFun Microphone

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Colour Stealing Underskirt

Sun, 02 Sep 2018 15:24:31 GMT

I've had an idea for an elaborate electronic skirt for, literally, years now. And no matter how long I waited progress just wasn't being made. At one point I realised that EMFcamp was fast approaching and I needed something for it. So I scaled back my ambitions, found a white tulle/net skirt on sale, and got to work.

I had a few Neopixel strands laying about the house, and found to my surprise that each 20 pixel (2" pitch) strand was almost exactly the width of my skirt. Two strands would completely encircle it. Rather convenient. And I wanted to be able to set the colour of the Neopixels from things around me, so I needed a colour sensor. I also wanted a potentiometer so I could adjust the brightness depending on ambient light, and would need a button to change between modes. Oh, and a microcontroller to make it all work. Which gave me this circuit.

( Details )

But white is very much not my aesthetic. Which is a large part of why I made this an underskirt. You can use this one underskirt with a variety of overskirts to achieve different effects. Here I've used a black crushed velvet skirt with uneven hem so that some of the glowing tulle/net still peeks out. In dark enough environments, there is a side benefit of seeming to exist in a puddle of light on the ground. (Which can be handy when trying to navigate a campsite.) Overall this skirt is fun, but not the most practical. Though I do foresee it coming in handy from time to time.

Skirt
Photo by chebe

Parts;
Fabric scraps
Petticoat
Skirt

Potentiometer
Adafruit Flora
Adafruit Neopixel strands
3-pin JST SM Plug + Receptacle Cable Set
Adafruit Colour Sensor
LilyPad Button Board

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DeepVR, and the search for a controller

Wed, 13 Apr 2016 19:35:26 GMT

DeepVR is this amazingly beautiful and serene underwater virtual reality that some very talented and extremely dedicated people have been working on for a while now. (It is seriously astounding, check it out if you can.) You are immersed in this other reality with the Rift, or now also the Vive. You navigate the world by controlled breathing. There isn't yet a popular controller to do this, so they have been trying various different configurations and learning from each iteration.

( One such type of belt )

Finished belt outside
Photo by chebe

Apologies for the poor photos, I was so focused on finishing them that I forgot to get decent photographs. The rush was because the belts have flown off with the team to Tribeca, where they will surely be put through their paces. I look forward to finding out how they held up and what didn't work so well.

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All the LEDs; or, Flora/Gemma and SewIOs

Sun, 06 Apr 2014 13:48:54 GMT

If you follow me on twitter you may have noticed that I have been playing with getting the maximum number of LEDs for the minimum amount of microcontroller that I can. Here's a short summary.

( Pictures! Video! Text! )

I have to thank Rob for being very patient in answering all my questions. And also to note that although I'm using the Adafruit wearables, Rob has been using the LilyPad boards (including the Tiny!) with the SewIOs quite successfully. Yay for interoperability! And finally, that they don't have to be regular LEDs, you can connect anything you could normally. I think RGB pixels, and smile.

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