LED clock source code

The source code of the LED clock is not very tidy, but it does the job. It first contains the definition of the hands of the clock, for one quarter. These are given by move up and move right markers, two bits at a time. I also added tables for mapping X coordinates and multiplying a number with 5, which, together with a bit shift, is convenient for also multiplying with 10. Then there are the routines for drawing digits. Digits have been optimized for the least amount of LED needed to display them, as displaying fewer LED allows brighter LED. The "second hand" is actually a single LED that moves in a square around the clock, and its table defines that movement. Initialization is as usual, with the A/D converter for reading the temperature.

The drawing routine has a memory bank that retains the image, which is rebuilt every time a display is made. For this rebuilding separate routines exist, one to display a single pixel, ones that draw entire digits, and ones that draw hands. A cursor keeps track of where things are currently being drawn. There is a separate set of routines to allow a scroll text on the clock, which is used to announce birthdays (not completely implemented yet) and a help text (which currently randomly enables itself). Then there are routines to display the temperature graph over the last 15 minutes, 15 hours and 15 days. Each LED position is 2 degrees Celcius. Not very accurate, but still interesting to see. Actually displaying things is done by "RefreshDisplay" which draws all the LED that are on. It skips LED that are off, to ensure that the remaining ones are brighter (this means that a display with more LED on will have these LED dim a bit).

Then there are routines to handle the two buttons, which are used to navigate through the different menus and submenus, including the setting of the alarm time and the alarm count down options. Updating the clock is also done this way. I also started on a teddy bear mode where it would display certain animals as pictures, but this has not completed yet.