Templateize Your Timetable With EPaper Templates

To date, e-paper technology has been great for two things, displaying static black and white text and luring hackers with the promise of a display that is easy on the eyes and runs forever. But poor availability of bare panels has made the second (we would say more important) goal slow to materialize. One of the first projects that comes to mind is using such a display to show ambient information like a daily summary weather, train schedules, and calendar appointments. Usually this means rolling your own software stack, but [Christopher Mullins] has put together a shockingly complete toolset for designing and updating such parameterized displays called epaper_templates.

To get it out of the way first, there is no hardware component to epaper_templates. It presupposes you have an ESP32 and a display chosen from a certain list of supported models. A quick search on our favorite import site turned up a wide variety of options for bare panels and prebuilt devices (ESP32 and display, plus other goodies) starting at around $40 USD, so this should be a low threshold to cross.

Once you have the device, epaper_templates provides the magic. [Christopher]’s key insight is that an ambient display is typically composed of groups of semi-static data displayed in a layout that never changes. The only variation is updates to the data which is fully parameterized: temperature is always integer Fahrenheit, train schedules are lists of minutes and hours, etc. Layouts like this aren’t difficult to make, but require the developer to reimplement lots of boilerplate. To make them easy to generate, epaper_templates provides a fully featured web UI to let the user freely customize a layout, then exports it as JSON which the device consumes.

The sample layout configured in the video below

The web UI is shockingly capable, especially for by the standards of the embedded web. (Remember it’s hosted on the ESP32 itself!) The user can place text and configure fonts and styles. Once placed, the text can be set to static strings or tied to variables, and if the string is a timestamp it can be formatted with a standard strftime format string.

To round out the feature set, the user can place images and lines to divide the display. Once the display is described, everything becomes simple to programmatically update. The ESP can be configured to subscribe to certain MQTT topics from which it will receive updates, or if that is too much infrastructure there is a handy REST API which accepts JSON objects containing variables or bitmaps to update on device.

We’re totally blown away by the level of functionality in epaper_templates! Check out the repo for more detail about its capabilities. For a full demo which walks through configuration of a UI with train arrival times, weather, both instant temperature and forecast with icons, and date/time check out the video after the break. Source for the example is here, but be sure to check out examples/ in the repo for more examples.

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Web Interface Controls Nixie Tube Clock

We love our clocks around here and we love nixie tubes as well. The combination of the two almost seems to be a no-brainer. With the modern twist of an ESP8266, Reddit user [vladco] built a minimalist nixie tube clock.

The build starts with the nixie tubes, Russian In4s, each one mounted on its own small circuit board. Each board is chained together and they’re mounted on a wooden frame. The frame is mounted inside a nice wooden case which was designed in Fusion 360 and milled out of oak at a local hackerspace.

There are no controls on the case. No buttons or knobs. This clock is set via the EPS8266 which gets the time and updates the shift registers that set the numbers on each of the tubes. The clock dims at night so it’s not as bright. [vladco] wrote a web UI to set the time and interact with theĀ  tubes.

The code and files for the case and circuit board are available online. The result is a nice, minimalist clock for your desk. There are plenty of clock builds on the site, several built from nixie tubes, including another nixie tube clock with an ESP8266, and another.

via Reddit