No matter the type, Nixie Tube projects always look fantastic, and Mark Smith’s ETA Nixie Tube Clock is no exception. As the name suggests, this clock doesn’t show current time, but rather how much time you have left before you’re late for work, school or other appointments.
Smith’s build uses six IN-4 Nixie tubes for the ETA display, which require 165v with a sustained current of 2.5mA. A Raspberry Pi Zero W controls the display and connects to the internet over Wi-Fi to provide current time as well as the ETA for any number of destinations. For the ETA portion, Smith tasked the Google Directions API, which includes real-time traffic data for a host of local, state and national destinations.
As a power-saving feature, Smith incorporated an IR motion sensor that turns off the display when no motion has been detected, which helps save tube life as well. His entire design- schematics, PCB layout, and BOM were done using KiCAD, while the Pi coding was done using Python.
The ETA clock is coded to display both the local time (in any area) and can show up to 10 different ETA time. They display is programmed to switch between local and ETA times between five and three-seconds respectively. The Great thing about Smith’s ETA Nixie Tube Clock is that both the hardware design and software are open-source, which can be found on the SurfnCircuits website along with a complete build walkthrough.