We, a hobby group called The Robot Group in Austin, TX applied and were approved. They sent us parts to build some projects with in one build night. Among this kit was 555 timer IC's, Solderless Breadboards, 9V batteries, LEDs, Resistors and a grab bag of parts or what I call 'floor scrap' which included some capacitors and ICs and mysterious goodies. We brainstormed several projects, but wanted to stay true to the challenge. Build projects in a day with mostly the parts provided.
I took lead on an Idea I had, an LED blinky wire sculpture. Something neat that could be done in an evening.
Note, this instructable does gloss over the circuit building part, so familiarity with electronics is suggested.
Step 1: Pick Design, Create the Mesh
I decided to do something organic, animal shaped, but an abstract shape would also work. Other material such as polished rocks and drift wood, maybe something odd like chicken bones can also be incorporated.
I chose to make something frog like, so I started with google image search, looking at frogs, frog skeletons, and the like to get a structural shape. I decided to keep things symmetrical by bending in the middle of the wire to form the jaw shapes and body parts making identical leg structures to attach to each side. I formed the eye shapes and feet shapes and tied everything together. Legs started out as two wires or one wire bent around the body from the frame and then a third or fourth wire was added later so it has a three dimensional quality. The 20 to 22 ga wire works well for looping around and can be pulled tighter with pliers if needed so everything is held together nicely.
Don't cut your fingers on the wire pieces or let them poke you in the eye. Use gloves, goggles as appropriate to your safety.
Step 2: Finish the Wire Mesh
Step 3: Blinky Circuit
I choose 220 ohm resistors which at 5v a typical 2v LED will be driven at 15ma which is within its limit.
I didn't want the LEDs to be solid on but instead blink so I started with a basic oscillator circuit using the NE555 Integrated Circuit chip.
This provides an on off pattern at pin 3 that can be adjusted using different values of the capacitor. There are tutorials out there to get started building circuits like this blink circuit and using parts like the NE555 and understanding solderless breadboards and reading schematics. If this is too advanced then simply wire each LED to a resistor and connect to the battery, you can also purchase LEDs with built in blinking circuit.
I decided that it would be more interesting if different LEDs blink at different rates, and our random parts kit included a SN74LS163 which is a binary counter. Connect the enable pins to +v and providing pulses to it allows different outputs to blink at 1/2, 1/4, 1/8, 1/16, etc of the incoming pulse rate. Google binary counter for more info. Unfortunately this is a 5v part and cannot be powered directly from the 9v. The 2 choices were to use a 5v regulator to drop the 9v down to 5v such as the LM7805 or to start with a 5v supply such as a USB phone charger.
Using an oscilloscope is neat to show the waveform here, but not needed for getting this sort of simple circuit up and running.
I learned this stuff years ago using the Getting Started In Electronics book by Forest M Mims III. Thanks Mr. Mims.
Step 4: Attach LEDs to the Sculpture
This is where I enlisted the assistance of fellow people at The Robot Group making this a fun group project.
LEDs have an Anode (+), usually longer lead wire and Cathode (-) wire, usually has a flat notch on the otherwise round body of the LED. When in doubt, test them in the circuit. They won't light up backwards.
This circuit has all the Cathodes going to ground and a separate resistor to each Anode.
Since the sculpture wire is conductive, we chose to solder a wire only to the anode and use heat shrink tubing to insulate the connection after it is soldered (lasts longer than electrical tape).
The LED is positioned and the Cathode wire is gently wrapped around the conductive sculpture. It can also be soldered as we did, but solder may not adhere well to some types of floral wire.
Tested each LED as it was attached.
The wires were all brought out of the leg of the sculpture and trimmed to a common length for connecting to the circuit. One common ground wire was attached to the sculpture wire.
Seen here, we used a clippy hands thingy to hold the LED while soldering on the wire and a lighter or hot solder iron to shrink the heat shrink tubing to insulate the positive lead. One of the 3 helpers is seen here learning to solder.
Don't burn yourself. Read and understand the long term risks of working with lead solder (wash your hands after) have a well ventilated area and don't inhale the vapors of the rosin, some people eventually develop allergic reactions from over exposure.
Step 5: Plug Wires Into Breadboard
Special thanks from all of us at The Robot Group to Jameco for providing us these free parts:
Battery, Solderless Breadboard, NE555 timer and binary counter ICs, LEDs
We really enjoyed the group activity at our weekly meeting in Austin, TX