This is a project of mine that may or may not meet your definition of completeness. If you think about something that works reliably, is documented and usable, then consider it complete. If it's something polished, finished and never worked on again, then this is not a complete project.
Regardless, here it is: an AVR-based bicycle computer, using AtMega8 and Nokia 5110 display module.
the project is open source, including software and hardware. It's quite easy to build - I have more experience in software than hardware. Regardless, I made a tutorial available on the project page, if anyone wants to make one.
- Current speed
Average trip speed
Crank rotation frequency
Speed vs distance and time plots
Wheel circumference configuration
The real power of this device is the ease to add new features and sensors - the project wiki has a full documentation of the API needed to achieve this.
It should be quite easy to port to some other microcontrollers (Arduino) or to attach different screens to it.
This is how the device looks so far:
And on a bicycle:
If there's some real interest in the project, I'm planning to keep working on it. Obviously, it needs a better packaging, and I have a few features on my mind too (clock, SD card logging, compass/GPS sensor etc).
The project page: http://rhn.github.com/jazda/
There you can find the source, schematics and all the necessary guides to start hacking on it. To build it, you need the GCC toolchain, and it's been tested only on Linux.
If there's anyone else who wants to try it out, I will be more than happy to help. Also, patches/ideas welcome :)
EDIT: to the admins: adding a file to "projects" gives me
Failed to load module Freaks Files (at function: "saveFile")