Clock design to help manage open hours at Vancouver Hack Space (VHS)

When this is done, it should be a design for a two line clock using 2.3" 7-segment LED displays. The two rows are:

• current time
• closing time (i.e. when the night's responsible keyholding member is planning to leave)

The clock is AVR-based and communicates over a serial link with a Raspberry Pi, which performs NTP time sync and updates variables on http://api.vanhack.com based on the clock's state. http://isvhsopen.com references the VHS API to display the open state and the closing time.

There is a separate readme for the Raspberry Pi setup instructions and Python scripts.

The schematics and board layout are done in KiCAD. The project has one main board with the AVR MCU, power, LED drivers and various connectors on it, as well as a board designed to hold four 7-segment LED characters for displaying a time value. Two copies of this LED board are required.

Enclosure design is TBD. I'd like to do it with a Lamicoid faceplate, but it may end up being easier to do it with laser-cut acrylic or plywood, since that seems to be what is commonly available around VHS.

The firmware is currently a work in progress. It is written in C for the avr-gcc compiler.

Once complete it should support:

• Two rows of 7-segment output
• Keypad input
• Serial I/O, probably with an AT style interface
• Drift correction for the clock
• A reasonably intuitive interface for setting times and general use

The Raspberry Pi's code is written in Python and is described more here.

See bugs and to-do's for remaining work.

The enclosure is a laser cut box made from 5mm ply, primarily designed and built by Luke Closs - thanks Luke! The basic box design was created with http://boxmaker.rahulbotics.com with the following parameters:

• Width: 350mm
• Height: 280mm
• Depth: 60mm
• Thickness: 5mm
• Notch length: 12.5mm (automatic)
• Cut width: 0.25mm