So far, the watch has been working great!  I have finished off the prototype case.  I drilled and tapped holes for four small screws so that I no longer need to use tape to hold the back on any more. It almost looks like a real watch!

Here is a close-up of the the corner:

The black screw is holding on the back. It’s positioned near the pin holding the band so that it can be clamped tightly, even if the plastic flexes. I was careful to not tighten it too much for fear that I’d strip out the threads.

The silver screw head (under the yellow kapton tape) is the charging post. Putting voltage on this pin charges the battery and also set the time -- no more disassembling the watch every night!

This case was originally intended to be metal and serve as the other half of the charging circuit. But, since my prototype is non-conductive plastic, I had to bring this connection to the outside of the case. That’s the metal “ground” flap shown at the left of the picture.

The tape is temporary - it holds down the metal flap to keep it from itching my wrist.

Until I make a cradle, here’s how I charge the battery:

The aluminum block on the right is holding down the wire to maintain the ground connection (the black negative lead to the power supply is not visible in the picture).  Incidentally, that block is the raw material that I’ll use to make the first metal case.

While I was doing surgery, I made some improvements to the software:

1. •The oscillator that keeps time wasn’t adjusted quite right, so it would stop occasionally. Normally this is is fixed by changing the capacitor that are part of the circuit, but the processor I’m using includes a variety of capacitors built in. I selected the correct ones by changing the software.
   

2. •The first serve wasn’t quite right: the paddle didn’t always go towards the ball. It would still bounce whether the paddle was there or not, so it looked a little confusing.
   

3. •When the battery is low, the program turns off the screen to save energy. The time is still kept but not displayed. I lowered the current in this mode so that the time would be held longer & also modified the behavior to extract a little extra life out of the battery.
   

The software in this watch is completely filled up... every byte of memory is used!

Next up: I’ve made a slight modification to the case, so I’m ready to make a metal version. And, I’ve got to order some more parts to make a charger. Plus, I have working on the new “Plans” section of the website (see the very top of this page).