Which switch is which?

I haven’t been working on the Pocketwatch much because I am waiting for the display, and I have been rather nervous about constructing the encoder/switch with my limited mechanical abilities. But tonight I was putting off starting the last Harry Potter book (Don’t tell me! I haven’t read it yet! *fingers in ears* NAH NAH NAH) and I decided to head into the lab and fiddle around. I ended up picking up the pocketwatch and constructing the switch mechanism. It actually turned out rather well, nice and smooth, not wobbly. It still needs finishing, but here it is:

The tiny disc magnet is glued into a slot in the plastic shaft on the left. The bushing is made from a drilled out and turned down 2-56 nylon standoff. Pressing down on the shaft engages the tactile switch with a satisfying *CLICK* and spinning the shaft will cause the hall effect sensors to sense the rotation.

The encoder started as a sketch:

Then someone on the Steampunk Tactile forum suggested using one magnet and two hall sensors. Great idea! I built up a demo to try it out:

Lo and behold, it works!

Syndicated 2007-07-28 06:49:10 from robotguy.net/Blog

The display is on it’s way

I ordered the OLED last friday. The US distributor was out of stock, so I had to order from Australia. Here is a 1:1 mock-up I did to get an idea of the display size:

I spent quite a while on Sat. night grabbing pics of pocket watch dials from eBay and resizing them.

Syndicated 2007-07-16 18:24:30 from robotguy.net/Blog

SP-PDA update

I went to the local antique fair today and found this pocket watch case for $5:

I have also started a power budget:

Power Budget

The good news is that I found a 300mAh battery that fits in the case along with the electronics, so I should get 4.7 hours of runtime and/or 18 days on standby before I need to recharge the battery.

Syndicated 2007-07-09 00:25:54 from robotguy.net/Blog

OLED info and demos

There is a demo of the 128 x 128 OLED here. It has the same drivers as the 96 x 64 version that I am using. Check out the unicorn animation near the end. I am hoping I can animate an imp and have the option of having a Dis-organizer.

Syndicated 2007-07-06 16:14:11 from robotguy.net/Blog

Steampunk PDA - Project planning

I decided to spend a little more time planning this project than I usually do (a stitch in time and all that…), so I started some design documents on Google docs:

Feature List

Schedule

Hopefully this will help keep me on track a little better, and avoid scope creep.

Syndicated 2007-07-06 15:20:01 from robotguy.net/Blog

PDA, take two (or is it three?)

While I have been thrilled with the success of the 128×128 LCD, I happened upon an oLED display today that would allow the whole thing to be miniaturized to the point it would fit in a pocket watch:

Syndicated 2007-07-04 04:24:08 from robotguy.net/Blog

And now for something a little different…

P.S. I have uploaded a bunch of robot pics to my new Picasa web album here.

Syndicated 2007-04-18 16:34:14 from robotguy.net/Blog

Let there be…. uh…. color

I am having so much fun with this PDA/Tricorder project! Although the 128 X 64 mono LCD is cool and all, I just had to buy the 128 X 128 color LCD from Sparkfun that I’ve had my eye on. I wired it to my ATmega128 breakout board and powered the whole thing with my STK500 set to 3.3V

Voila! I had a nifty color LCD for my project. Here are a few screenshots:

I also picked up a few Hammond electronics enclosures ( I love electronics enclosures! I collect them…) from Allied. I get a great deal through work, plus free shipping. I got the 1553B and the 1455J1201. Of course I am also considering putting the electronics into an actual tricorder case. I bought a scratch-build kit from GMProps (look him up on the tricorder props forum), but it proved to be too much for me. Maybe I’ll try a Playmates Tric from Ebay.

Syndicated 2007-03-09 05:20:36 from robotguy.net/Blog

Useable accelerometer data

Here’s a few places I found good stuff about filtering…

• http://lorien.ncl.ac.uk/ming/filter/filewma.htm
• http://www.dsptutor.freeuk.com/dfilt1.htm

Syndicated 2007-02-28 00:55:35 from robotguy.net/Blog

Toward a Buttonless Interface

I have been struggling for a while with the lack of user input on the PDA project. I had considered adding an interface through the RF transceiver, but that would mean I would need to be near a PC. I have been unable to find any pushbuttons that I like to install on the face. So I did the next best thing. A sharp sideways tap on the right side of the enclosure brings up a menu, with a small circle next to the selected item:

Tilting the unit in the y direction moves the selection circle, and another tap selects the item. It still needs a bit of tweaking. It seems much easier to tilt in the x direction, because I tilt the unit towards my face when looking at the screen, and that makes the selection circle move down the llist.

Here are links to a few thing I found during my research into tiny user interfaces:

• TiltType: An Accelerometer Based Text Entry Method
• Sensing Techniques for Multi-Device Interfaces (PDF)
  
• Shake Them Up! A Movement Based Pairing Protocol
• Bringing Sketching Tools to Keychain Computers with an Acceleration-Based Interface
• GUI Development: Embedding Graphics Part I Part II
• Variability in Wrist-Tilt Accelerometer Based Gesture Interfaces
• Detecting Freefall with Low-G Accelerometers,Measuring Tilt with Low-G Accelerometers

Syndicated 2007-02-27 19:56:00 from robotguy.net/Blog