Bounding Bandersnatch
Projects, mostly involving electronics, and other burblings.
Monday, September 5, 2011
recirculating snow globe
Apart from the actual figurine to go in the thing, I've mostly got this recirculating snow globe together. I've put an adjustable flow aquarium pump into a separate glass container that has an opening the same size as the gasket for the bottom of the globe. Sealing it all up will be a bit of a trick. I've tested it with nothing but duct tape around the base, though, and apart from a little leaking around the power cord cutout, it worked great!
Meet Professor Fuzzles!
Professor Fuzzles is an animatronic bunny head that looks around and sniffs. Well, a proper bunny sniff would scrunch the nose, but instead it's moving its head a bit up and down. Close enough! This head will get reunited with its body once I mount everything on its display shelf.
Here's the stuffed bunny head I started with. I liked that it had a slightly miffed-looking expression, and thought that might work nicely in the haunted house.
Disapproving bunny disapproves! |
I replaced its eyes with a pair of my slightly larger toy eyes modified to glow by adding a pair of LEDs behind each eye. I put yellow LEDs behind a pair of green eyes.
After eye replacement surgery. |
Here the eyes are lit. |
I've given the Professor a top hat, found in a hobby store. The head is sitting on top of a pair of standard-sized servos in a pan-and-tilt bracket assembly, mounted on a Maker Beam frame. I'd started out using micro servos, which fit better in the head, but the gears stripped out before long. The standard sized servos seem to be plenty tough for Professor Fuzzles' noggin.
Sunday, August 21, 2011
glowing toy eyes
So I want to give my animatronic critters glowing eyes. I've got an eye together now that I think will serve the purpose. It's a toy eye with two LEDs stuck between the eye and the backing piece, with cardboard wrapped in foil around the sides.
Here are the LEDs before they went around the eye. I've soldered a 47 Ohm resistor to one leg of each of the yellow LEDs. The foil-wrapped cardboard piece is taped to one of the LEDs here. I'm using speaker wire to hook it all up.
The painted eye diffuses the LED light well, and the yellow light behind a turquoise-painted eye produces a nice effect. Although not very bright, in the dark of the haunted house these eyes should show up well.
I intend to wire up a matching eye for this one, and mount them both inside a bunny head. The bunny head I want to put on a pan-and-tilt bracket, to make it look around.
Here are the LEDs before they went around the eye. I've soldered a 47 Ohm resistor to one leg of each of the yellow LEDs. The foil-wrapped cardboard piece is taped to one of the LEDs here. I'm using speaker wire to hook it all up.
The painted eye diffuses the LED light well, and the yellow light behind a turquoise-painted eye produces a nice effect. Although not very bright, in the dark of the haunted house these eyes should show up well.
I intend to wire up a matching eye for this one, and mount them both inside a bunny head. The bunny head I want to put on a pan-and-tilt bracket, to make it look around.
Hullabaloo, the flapping monkey
Update to the flapping monkey project: it flaps, and it has a name, Hullabaloo. There's still work to do to get it looking better. The body can be arranged around the frame to hide the shoulder joints a bit better. Also, the fabric from the head is just sitting loose on top at the moment. I'm considering giving Hullabaloo a different head, from another animal.
Here I'm using an Arduino Mega to send commands to the SSC-32 servo controller, so it's nice to have that working. I'll likely use the SSC-32 to run multiple toys.
Tuesday, August 16, 2011
purple flappy monkey, mostly there
Here is the framework for it with one flapping arm attached.
Clothespin hinge |
I'm controlling it right now with an SSC-32 servo controller.
At the moment I've got the second arm attached and the base inside the monkey. I just need to cut some holes behind the ears to accomodate the fishing line moving up and down, and get the head situated around the frame. Then it's flappy monkey time!
Saturday, August 13, 2011
blinking cabbage patch doll
Here I've connected the eyes of a cabbage patch doll to a servo, so I can control opening and shutting her peepers. The doll came with weighted eyes that shut when she's reclining, and open when she's upright.
I started out by cutting out a piece of the back of the head, to get acces to the eyes. The eyes sit in molded sockets that are part of the rubber head. I slit open the socket backs, but left them mostly intact so I could put the eyes back in them. The eyes had a black plastic cover on the back that connects to the metal case surrounding the eye in the front. I sliced off most of the black plastic cover with a Dremel tool, but left a ring of it to hold the works together.
To connect to the eyes, I superglued a large bent paperclip to the back of each of eye.
The servo I mounted to a base built from Maker Beam. I attached the servo arm to the paperclips using a zip tie and some fishing line, so it could have a little play. Here is the head with the eyes moving while sitting on the bare base.
For now, I'm using a Pololu Maestro servo controller with its software to test. I intend to try out some others, and figure out how I want to connect together several dolls and stuffed animals for a display.
So there it is! The eyes move slower than I might like, and also don't open and close completely, but I'm happy enough with the project as it is.
Tuesday, August 2, 2011
Frankenshirt
This is a shirt I made last November that changes the colors of the cat's eyes when the right wrist is rotated up or down.
A LilyPad Arduino board controls it, powered by one AAA battery. An accelerometer on the right cuff detects movement. When the right hand is hanging down, the cat's eyes glow red. As the hand is raised, the color of the cat's eyes moves through the color spectrum. When the hand is raised perpendicular to the ground, the eyes glow violet.
The eyes are two RGB LEDs, covered with a piece of plastic to diffuse the light.
Here's a video of the thing in action:
Making Frankenshirt
To start, I made a stencil of the cat outline, then painted the image onto a second shirt using spray fabric paint. Spray stencil temporary glue came in handy for this. The cat outline is based on a drawing in the Neil Gaiman graphic novel series, The Sandman.
I cut a square out of this shirt around the cat image to place over the electronics on the dark brown shirt.
I started sewing the electronics into the dark brown shirt by sewing a strip of conductive braid down the right arm, as well as a strip of conductive fabric on either side of the braid. The braid has three separated tinsel lines in it, so between the braid and the two strips of conductive fabric, I had five lines to connect the accelerometer on the cuff to the LilyPad on the shoulder. These lines are for the x, y, and z axes, and for power and ground connections. As I'm only using two axes for rotation detection, I could have left out one line on the sleeve.
I used conductive thread to sew in the conductive fabric.
accelerometer sewed onto shirt cuff |
To connect the LilyPad to the two RGB LEDs on the front, I sewed a length of conductive braid and a strip of conductive fabric across to the front. The end of the braid I cut up to separate out the three tinsel lines, which I then sewed to the shirt. I insulated the LED lines with black fabric paint.
I cut out a bit of a plastic milk jug a friend saved for me to use, and sewed it over the LEDs. Then I finished the design by attaching the square of fabric with the cat design, using spray fabric glue, and sewed around the edges of the square.
Where's the code?
Oh, here it is!
/* * Change color of an RGB LED based on the angle of rotation * of y/x from an accelerometer, so as to move through the full * color spectrum as the accelerometer turns 180 degrees. * * Used with an ADXL335 analog three-pin three-axis accelerometer. * * Based on the Sleeping Arduino sketch by Ed Halley. * (The Pummer RGB interpolation class is unchanged.) * * Released (cc) Creative Commons Attribution Only * Kathryn Killebrew * */ #include/* Pummer: * A simple RGB color-interpolating helper class. * * When creating one, tell it which three output pins to drive PWM signals. * If your RGB device is common-anode, it can reverse the PWM for you. * Don't forget to limit current to each LED with a resistor (e.g., 220ohm). * * At any time, tell it what color to become by calling the goal() method, * and how fast to transition to that color. * * Call the pummer's loop() method occasionally to let it set the PWM * outputs to the LEDs. */ class Pummer { byte lR, lG, lB; byte nR, nG, nB; byte wR, wG, wB; int pR, pG, pB; unsigned long last, when; boolean reverse; public: Pummer(int pinR, int pinG, int pinB, boolean anode=false) { pinMode(pR = pinR, OUTPUT); pinMode(pG = pinG, OUTPUT); pinMode(pB = pinB, OUTPUT); nR = nG = nB = 0; reverse = anode; show(); goal(255, 255, 255); } void show() { analogWrite(pR, reverse? (255-nR) : nR); analogWrite(pG, reverse? (255-nG) : nG); analogWrite(pB, reverse? (255-nB) : nB); } boolean done() { return last == when; } void goal(byte r, byte g, byte b, unsigned long speed = 500) { lR = nR; lG = nG; lB = nB; wR = r; wG = g; wB = b; last = millis(); when = last + speed; } void loop() { unsigned long now = millis(); if (now > when) { if (last == when) return; nR = wR; nG = wG; nB = wB; last = when; } else { nR = map(now, last, when, lR, wR); nG = map(now, last, when, lG, wG); nB = map(now, last, when, lB, wB); } show(); } }; /* Accelerometer: * Receive input from a 3-axis device, and perform some useful calculations. * * Specify the three axis pins using analog pin numbers. * These are usually adjacent on the common breakout boards. * * Call the accelerometer's update() method occasionally to update the * current values from the hardware. */ #define ANALOG0 14 class Accelerometer { int p[3]; // which analog pins int a[3]; // acceleration, zero-based int b[3]; // acceleration bias/calibration information float r; // angle of rotation public: Accelerometer(int pinX, int pinY, int pinZ) { pinMode((p[0] = pinX) + ANALOG0, INPUT); pinMode((p[1] = pinY) + ANALOG0, INPUT); pinMode((p[2] = pinZ) + ANALOG0, INPUT); for (int i = 0; i < 3; i++) { b[i] = 512; } r = 0; } void update() { for (int i = 0; i < 3; i++) { a[i] = analogRead(p[i]) - b[i]; } r = 0; } void dump() { Serial.print( "x="); Serial.print(a[0]); Serial.print("\ty="); Serial.print(a[1]); Serial.print("\tz="); Serial.print(a[2]); Serial.print("\troll="); Serial.print(roll()); Serial.println(); } int accel(int axis) { if (axis < 0 || axis > 3) return 0; return a[axis]; } float roll() { if (r != 0) return r; r = atan2(a[1], a[0]); // rotation of y / x return r; } }; void loop() { ; } // we do our own loop below void setup() { Serial.begin(9600); byte newColor[3] = {0,0,0}; // RGB values, 0 - 255 float angle; // angle of rotation, in radians int colorPlace; // angle mapped to range of color values int rainbowState; // which state of change color is in byte incColor; // if adding color to mix, how much byte decColor; // if removing color from mix, how much int div = 0; // counter for averaging angle readings int numReads = 8; // number of readings to average float rollReads = 0.0; // running total of rotation angle readings // initialize with pin numbers for LED colors and accelerometer axes Pummer pummer = Pummer(4, 3, 2, true); Accelerometer accel = Accelerometer(A0, A4, A2); while (1) { delay(20); accel.update(); // read accelerometer axes angle = accel.roll(); // get a rotation angle reading angle = abs(angle); // show full spectrum in 180 deg. (have angle in radians, ranges from -pi to pi) rollReads += angle; // accrue readings for average if (--div <= 0) { angle = rollReads / numReads; // get the average angle reading rollReads = 0; // map angle to range of color values with floating-point math colorPlace = (int)( angle * 1535.0 / M_PI + 1 ); // what in-built map function does, with int math //(x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min; colorPlace = map(colorPlace, 0, 1535, 1535, 0); // reverse range for red at bottom, violet at top rainbowState = colorPlace / 256; // bin color number into change state incColor = colorPlace % 256; // remainder is amount of partial color to fade in decColor = map(incColor, 0, 255, 255, 0); // reverse partial color range for fading out // make a rainbow if (rainbowState == 0) { // red to orange newColor[0] = 255; newColor[1] = incColor; newColor[2] = 0; } else if (rainbowState == 1) { // orange to green newColor[0] = decColor; newColor[1] = 255; newColor[2] = 0; } else if (rainbowState == 2) { // green to teal newColor[0] = 0; newColor[1] = 255; newColor[2] = incColor; } else if (rainbowState == 3) { // teal to blue newColor[0] = 0; newColor[1] = decColor; newColor[2] = 255; } else if (rainbowState == 4) { // blue to purple newColor[0] = incColor; newColor[1] = 0; newColor[2] = 255; } else if (rainbowState == 5) { // purple to red newColor[0] = 255; newColor[1] = 0; newColor[2] = decColor; } else { // red newColor[0] = 255; newColor[1] = 0; newColor[2] = 0; } // show colors pummer.loop(); if (pummer.done()) { pummer.goal(newColor[0], newColor[1], newColor[2], 100); } // reset counter for readings div = numReads; // print values accel.dump(); } } }
Labels:
accelerometer,
arduino,
cat shirt,
LilyPad,
wearable electronics
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