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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 Prowler50mil 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!

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.

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.

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.

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.

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: