Powerleap and piezo technology

Using piezo power to harness the kinetic energy of people walking, cars moving, dancers and then create energy - Powerleap

Links to piezo kits and the humdinger, a piezo related wind turbine

energy harvesting clearing house of information VERY COOL

and a cool copper sconce from Holly Solar Products

Clock that writes time

Using two servos to control a pen, a RTC can send the time to a pen that writes the time on a piece of paper that then moves forward and shows the time.
If the sketch can control the pen, then the door is wide open to get the pen to write anything.  Could use a joystick learning program to "learn" numbers and letters.

There is some interesting work on candlebot from a Bristolian that may be helpful.

Candlebot video on YouTube

Multiple options on controlling pen movement.

1) 2 servos, easy but could be messy!
use the servo.h and joystick tutorial

2) X and Y stage using rods or belts.
Makerbot uses both and there are some interesting images and ideas there.  For the threaded rod version, the Z axis of the Makerbot works, uses belts as well.
Makerbot also has a great X-Y stage, controlled by stepper motors and belts - lot of work there

Also some ideas at bothacker and reprap

Pulleys can be sourced from McMaster

Draw shape with arduino

I could potentially use a PIR sensor or  IR sensor to draw shapes of 3-D objects. In a housing the PIR could be passed over an object then the distances calculated and plotted in processing to draw the shape.  Data could be stored on an SD card as a coordinates and then subsequently plotted.  Real time plotting would require a PC to be attached.

USB Stick Storage

After reading the excellent "Practical Arduino" book, there is a lot of talk about storing data on a removable USB Stick using a VDIP1 chip from Saelig. Good explanation and blog on interfacing chip to arduino.

Building waterproof housing

Great ideas from Diver Dave

1.  For good waterproof seals on cable glands use "braided shield cable", and sometimes Molex connectors
2. Introduction to the lathe from AGI
3. Get a milling machine for $4000
4, Delrin is good stuff
5. Good wiki on o-rings
5

Waterproof connectors

Electrical through bulkhead connectors are available from Digi-Key (#288-1167-ND) submersible to 5 bar (40-50meters).  Also from another supplier. These ones from McMaster look similar but no specs available


Check out the longer thread, elongated thread version #cd07cr-bk, and also the strain relief ones # cf07cr-bk from a sealconusa that provides samples. Plastic but 300' submersible or plated metal.

Battery capacity

For increased voltage, but not capacity use batteries in series.  For increased capacity (same volatge), use batteries in parallel

 Capacities of akaline AA typically 2000 mAH, and C cells 6000mAH

Great 9V connector jameco #216452