Automating The Design Of Word Clocks

Word clocks, or a matrix of light-up letters that spell out the time, are a standard build for all enterprising electronics enthusiasts. The trouble is finding the right way to drive a matrix of LEDs and the significant amount of brainpower that goes into creating a matrix of letters that will spell out the time without making it look like it’s supposed to spell out the time.

For his Hackaday Prize entry this year, [Stephen Legge] is creating a standard toolkit that makes word clocks easier to build. It’s a hardware and software project, allowing for LED matrices of any reasonable size, and the software to make a grid of letters that only spells out the words you want and not the four-letter ones you don’t.

The hardware for this project is built around the IS31FL3733 LED driver from ISSI. This is an interesting chip that takes I2C in and spits out a LED matrix with very few additional support components. This chip provides [Stephen] with a 12×16 single-color LED matrix, which is more than enough for a word clock.

Where this build gets slightly more interesting is the creation of a custom matrix of letters that will still spell out ‘quarter to noon’ when lit in the appropriate way. This is a big challenge in creating a customized word clock; you could always borrow the layout of the letters from another word clock, but if you want customized phrases, you’ll either have to sit down with a pencil and graph paper, or write some software to do it automatically.

It’s a great project, and since all of [Stephen]’s work is being released under Open Source licenses, it’s a great entry to the first portion of the Hackaday Prize where we’re challenging hardware creators to build Open Hardware.

9 thoughts on “Automating The Design Of Word Clocks

  1. I just used a word search maker that allowed me to specify direction to avoid “backwards” words.

    I built my own top and bottom rows, so I could put my own strings at the top left and bottom right.

    1. It’s not that easy. The order of certain words matters. e.g. “quarter” needs to be before “past”. Secondly, there needs to be some space between certain words, or you would end up with “quarterpast”.

  2. It’s not that easy. The order of certain words matters. e.g. “quarter” needs to be before “past”. Secondly, there needs to be some space between certain words, or you would end up with “quarterpast”.

  3. And what’s this use of “of” when telling time?
    “It’s a quarter OF Five.”
    Which quarter? The first, second, third, fourth?
    NO! It’s the fourth quarter of Four!
    Sheeeesh!

    1. I’ve been meaning to write it up forever: the mother of all word-clock threads in German. There is (crazy!) regional variation in the way people call out times here. Berliners say quarter-to-three, in Munich they say three-quarters-past-two, etc…

      There’s a word clock firmware that has like 20-odd different dialect modes. OK, I’m going to write it up now…

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