Milestone Reached!

Guess what! We hit a major milestone with the Analog Voltmeter Clock! Working, custom circuit boards! To celebrate, we'll be drawing three names at random from our email list and giving the winners a choice of any item from the Awkward Engineer Store.

The Technical Stuff:

(scroll to end for pics)

I've been told that nobody get's their first printed circuit board right, there are just too many tiny details that could go wrong. I was pretty nervous waiting for my boards to come back (I ordered 5 populated prototypes) and had a couple scary moments, but all in all, everything went pretty well. Here's the run down of what happened: I messed up an easy one, right off the bat. The holes for the screw terminal mounts that attach the meters to the board were sized for a 2mm screw, not 2.5mm. A couple minutes with a drill solved that problem. Luckily, there was still enough plating around the screw hole that I still could get electrical contact.

The pinouts on the PCB were different than the pinouts on my breadboard prototype. I slapped my forehead pretty hard, but then it was a quick fix in firmware. Fortunately, the ISP header was wired up the right way and I could still flash the chip's memory.

The firmware was written for the 20khz crystal I had on hand to build the breadboard. Again, a minor fix in firmware to change to the 32.768khz clock crystal.

The voltage divider on the board was designed to work with the potentiometer "mode" knob and an optional unpopulated "alarm" switch. (Future versions only...). One more fix in firmware was need to get the levels right for the different modes. The working clock! Running off an AA battery for about 2 weeks now!

The populated side of the board.

The board/meter screw terminal interface.

What's next?

Well, at this point, I feel like I've cleared all technical milestones and it's on to final pricing, campaign, and launch planning. The launch list (that means you guys!) is at a reasonable size for a small batch, so it's really up to me to pull the trigger.

Here's an example of what's still on my mind: Getting a custom meter scale ordered from the factory has a setup cost that needs to be defrayed by a couple hundred orders... or if I do a really small batch, I can make custom scales and assemble them on my own. The question is where does the small/medium batch line fall?

Other than that, stay tuned! I'm planning on attending the MIT Maker Faire on Oct 4th, so if you're around, feel free to drop by!