Atilla Clock

The Atilla team presents you here its handcrafted (well, almost) clock ! It's build upon an Arduino Uno with an additional network card and a 16*48 LED matrix. We chose to code it in C instead of Python or any other high-level language for after all, we're hackers.

Clock screen

The idea is to output the time on the upper side of the clock (thus on a 8*48 LED screen), and an animation on the lower side.

Every x minutes (can be parametrized), there is a transition on all the upper side. This is exactly the same system with the animations at the lower side.

Internals

For the Arduino only allows us 2 kB of SRAM and 32 kB of flash memory, we couldn't store all the transitions and animations at the same time. We then chose to buffer from network the stuff we need.

In order to do that, we have a running Python server sending whatever the clock asks, and choosing which transition or animation comes next when demanded, all that over HTTP.

Scheduling and general algorithm

This is pretty simple, and this applies (asynchronously) to both the animations and the transitions. Let's call any of these a run.

We loop infinitely on this :

• We fetch some information packets from the server (for instance to change some constants)
• Then we receive an special information package telling us which run is getting to come (how many frames, the total running time, ...)
• Eventually we double-buffer the frames (which we shall talk about later), meaning that we fetch one, and we output one, always one frame ahead the stream.

Frame system

Each run is actually a finite set of frames, a single frame being

Structure of a packet