Word Clock

Analog clocks are hard for most kids to read. Binary clocks are difficult for most adults. Word clocks, on the other hand, are effortless. Just read the displayed sentence: "It is eight fifteen".

The camera records this poorly.
In person, the display is sharp and easy to read.

The display consists of an LED matrix with a PCB light might in front of it, an idea which I first saw on Hackaday. Determining the proper arrangements of letters was a fun challenge that took ages, especially since I wanted the clock to display holiday messages as talk about later.

The primary PCB has all the electronics on it. Here I'm debugging the LEDs, which didn't work for months. I gloss over this in most of my blog entries, but most projects have tons of aggravating problems during development.

Once the LEDs were working, I needed to design a spacer between the PCBs and a stand to hold it upright. I used a CAD tool for the design and a 3d printer for the actual pieces. 80 degrees felt like a good angle and, if it wasn't, replacement feet are quick to print for other angles.

The clock is powered by a USB cable. It has a backup battery (actually a supercapacitor) that keeps track of the time and date for up to a week without power. When it powers up, it cheerfully declares, "I am a clock" before telling the time.

On holidays, it displays abbreviated holiday messages like, "H-a-p-p-y  m-o-m-s  d-a-y" for 21 different holidays, plus a birthday. Figuring out the perfect layout for this was tricky. Some holidays are simple (Happy MLK Day) whereas one or two require some creativity (Happy Scare Day because "Halloween" is too long).