A tilt and touch activated wristwatch using a "retro" style bubble 7 segment display.
This project was created on 06/02/2014 and last updated a month ago.
The PCBs and components have arrived time to heat up the soldering iron!
I'm still waiting for the PCB to arrive so in the mean time I have started designing the case for the watch. I started off using openSCAD as my 3D CAD software since I have used it before and it is open source. But after a while I got frustrated with having to descried the design in code and started using Designspark Mechanical instead, a great free (but not open source) piece of software.
Watch Case V1
I sent my PCB to the manufacture (oshpark.com) and it has already added it to a panel :-) hopefully I will have the PCBs at the end of the month. The only thing I forgot was to add a way to program the microcontroller... But that can be solved by soldering the programing wires directly to the pins.
When it comes the components I tried to choose packages that didn’t have super extreme pitch but still keeping them surface mount to keep the size of the PCB to a size that would fit on a wrist. For the microcontroller I chose the ATTiny2313 in a SO-20 package mostly because I have used allot of Atmels microcontroller in other projects but also because Atmel seem to have a large support in the OSH/maker/hobby hacker community. For the capacitive touch sensing I chose a IC from atmels Qtouch line, the reason for choosing to go the IC rout instead of having the microcontroller do the sensing is simply that this seemed like a simpler and faster way to get up and running.
The other components are 0603 resistors and capacitors a crystal oscillator and a tilt switch.