A project log for IoT Matrix Word Clock

The creation of a web connected clock that uses a character matrix (words) to display time.

mikeneiderhausermikeneiderhauser 09/24/2015 at 19:170 Comments

The most common approach that I when looking into word clocks is that each word is mapped to a a digital output. This is a good idea, however limits the recreation and portability of the hardware. The clock will display special days relevant to the clocks owner. Given the the possible customization of the display I cannot wire each word to individual pins. Instead, I will make a generic 16x16 LED Matrix Driver. My goal was to create this clock using (mostly) parts on hand and to make the design reusable in case any other family members or friends want a word clock. I more than likely will not optimize the design for battery operation.

The clock can be broken down into three parts. Each part will be documented in future project logs.

  1. The display matrix
    1. Straight forward 16x16 LED Matrix
  2. The display driver
    1. A controller (ATMEGA8 or ATMEGA328) that handles the multiplexing of the LED Matrix.
      1. Uses 74HC595 and ULN2803 for IO expansion and current sinking
  3. The controller
    1. Processes time and special events then writes to the display.
    2. Handles communications to the NTP server etc