Notes

Printrbot: Your First 3D Printer (Kickstarter).

Hannu’s Boatyard

Free Boat Plans

Last updated September 9. 2009

via Hannu’s Boatyard | Free Boat Plans.

This simple 2 transistor audio transmitter will send the sounds picked up in a room to any FM radio tuned to the same frequency as the transmitter, somewhere between 80 and 100 Megahertz. The expected range will be at least 100 feet and could be substantially longer depending on the parts used and the quality of your final product. This circuit is based on one that has been around since the 1960s and published thousands of times, so it is tried, tested and guaranteed to work if you follow the instructions. Performance is “OK”, but since this is the one of the most basic transmitter circuits possible, don’t expect high quality or rock solid performance.

via LucidScience – Build the BASIC SPY TRANSMITTER – Page 1 of 16.

There is lot’s of different cheap design for building your own 3D scanner, here are a few:

• SCAN Z do-it-yourself 3D scanner
• Building a Homemade Laser Line Scanner (CS6998, Spring ’01)
• Build Your Own 3D Scanner: Optical Triangulation for Beginners
• Scanalicious: A 3D Scanner GUI Client and Micro-controller Software
• 3-D Laser Scanner
• Scanalicious: A 3D Scanner for You and Me
• 3D Scannerless Scanning for Fabbers
• Splinescan: Open Source 3D Scanning
• NXT™ 3D scanner
• DAVID-laserscanner: Low-Cost 3D Scanner for Everyone!
• stripo-3DSCAN Light
• Structured Light 3D Scanning
• Milkscanner: Displacement Mapping
• Using Meshlab to Clean and Assemble 3D Scan Data
• Build your own 3D scanner
• 3D Photography on your desk/li>
• Build Your Own 3D Scanner: Optical Triangulation for Beginners/li>
• Project DASER: Introduction/li>

My first attempt at using the Arduino (Duemilnove). This sketch is based on this and that but mine uses 2 LEDs, one for the sensor and one for the feedback. And instead of getting bright when more ambient light is present, it turns OFF if ambient light is bright, stays ON in the dark and blinks if it’s in between.


//
// This example shows one way of using an LED as a light sensor.
// You will need to wire up your components as such:
//LED #1:
// + digital2 (N side)
// |
// <
// > 100 ohm resistor
// <
// |
// |
// -----
// / \ LED #1, 5mm, clear plastic is good (or translucent green lense)
// -----
// |
// |
// + digital3 (P side)
//
//////////////////////////////////
//LED #2 (only required if you don't have the on-board LED on pin 13):
// + digital13 (P side)
// |
// |
// -----
// / \ LED #2
// -----
// |
// |
// + Ground
//
// What we are going to do is apply a positive voltage at digital2 and
// a low voltage at digital3. This is backwards for the LED, current will
// not flow and light will not come out, but we will charge up the
// capacitance of the LED junction and the Arduino pin.
//
// Then we are going to disconnect the output drivers from digital2 and
// count how long it takes the stored charge to bleed off through the
// the LED. The brighter the light, the faster it will bleed away to
// digital3.
//
// Then just to be perverse we will display the brightness back on the
// same LED by turning it on for a millisecond. This happens more often
// with brighter lighting, so the LED is dim in a dim room and brighter
// in a bright room. Quite nice.
//
//
#define LED1_N_SIDE 2 // original code uses pin 2
#define LED1_P_SIDE 3 // original code uses pin 3
#define LED2 13 // LED 2 is on-board or external on pin 13 and ground
//
// -1 = very dark ; 1 = very bright
int extreme = 0;
//
void setup()
{
pinMode(LED1_N_SIDE, OUTPUT); // N side is output or input but starts w/ output
pinMode(LED1_P_SIDE, OUTPUT); // P side is alway output pin (drive low or high)
pinMode(LED2, OUTPUT);
}
//
void loop()
{
unsigned int waitDischarge, extenLimit;
//
// Apply reverse voltage, charge up the pin and led capacitance
digitalWrite(LED1_N_SIDE,HIGH);
digitalWrite(LED1_P_SIDE,LOW);
delay(30);
//
// Isolate the pin 2 end of the diode
pinMode(LED1_N_SIDE,INPUT);
digitalWrite(LED1_N_SIDE,LOW); // turn off internal pull-up resistor
//
// Turn LED on if ambient light is very dark or medium
if (extreme <= 0) {
digitalWrite(LED2,HIGH);
}
//
// Count how long it takes the diode to bleed back down to a logic zero
for ( waitDischarge = 0; waitDischarge < 65534; waitDischarge++) {
if ( digitalRead(LED1_N_SIDE)==0) {
// very dark (you might need to sligthly change this number depending
// on the color of the lense of LED #1 for example)
if ( waitDischarge > 6 ) extreme = -1;
// very bright (you might need to sligthly change this number depending
// on the color of the lense of LED #1 for example)
else if ( waitDischarge < 3 ) extreme = 1;
else extreme = 0;
break;
}
delay(30); // to avoid going above 65534
}
//
// Turn LED off if ambient light is very bright or medium
if (extreme >= 0) digitalWrite(LED2,LOW);
delay(200);
}


Here is a list of devices where you might be able to find stepper motors:

• floppy disk drives
• flatbed scanners
• printers
• plotters
• shredders
• faxes
• photocopiers
• robots
• webcams
• watches
• really old harddrives
• backup tape drives

Large stepper motors can be found in automated industrial equipment.

The instructions for this project are incomplete, but you basically step on the circuit on each tile with a conductive sole shoe (you could use aluminum tape glued under your shoe) to close the circuits. I hope to be able to add more detailed instructions and pictures soon. For now, you can check out http://royconejo.host.sk/, it was heavily inspired from it.

WARNING: Before anybody attempts to build this dance pad, please note that after a while I suddenly started having intermittent problems (it stops working). If I unplug it and plug it back, it starts working fine again for a while. I think the problem is caused by the wires connected to the circuit board being too long. It might change the inductance and/or capacitance too much and the circuit board can’t handle it. I don’t know much about electronics so If anyone know how to fix this, please let me know. I tried with a USB circuit board and a USB board with a PS/2 adapter without any luck.

Finished Dance Pad

Tools and Supplies List

• Tacker
• Wire Strippers
• Screw Driver & Screws
• Circular Saw
• Jigsaw
• Utility Knife
• Drill
• Drill bit (from 1/16″ to 1/8″ (1.5mm to 3mm) should do)
• Plyers
• Soldering Iron & Solder
• Sand Paper
• Pen
• Framing Square
• Hammer
• Punch
• Plywood
• Copper Wire (I stripped Cat5 network cable and phone cable)
• Measuring Tape
• Paint
• Cardboard
• 8×11 Paper
• Aluminum Tape
• Level (4ft)
• Large Tape
• Clamps
• Shoes with aluminum tape taped underneath (to create the shorts when you dance)
• USB Keyboard (or PS/2 if you current keyboard is not PS/2)

Note: A few tools and supplies are optional but they either make the job easier or the dance pad prettier.

Get keyboard circuits (find out how we will use them at http://www.instructables.com/id/S9XKHQXFDIY309O/)

keyboard opened

keyboard's circuit board

dance pad painted w/o wires

• Cut plywood

  Mine is 37″ x 37″ not including the header (where the circuit board is going to be installed

• Paint the hole plywood sheet black
• Stick strips of aluminum paper on edges and to create a grid with 9 even squares
• Paint symbols using red spray paint and stencils
  
  

  spray paint stencil

  
  
  

  spray paint stencil 1

wires_underneath_1

wires_underneath_2

wires_underneath_3

wires_underneath_4

finished_dance_pad_1

finished_dance_pad_2

Material needed:

• 3      2x4x8
• 32    3″ Nails (or wood screws)

Tools needed:

• Hammer (or drill if you choose to go with screws)

View the Drawing.