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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Cracking Weather Station Checksum

[BaronVonSchnowzer] is spinning up some home automation and settled on an inexpensive ambient temperature sensor which is sold to augment the data a home weather station collects. He found that the RF protocol had been reverse engineered and will use this information to harvest data from a sensor in each room. In true hacker fashion, he rolled his own advances out to the Internet so that others may benefit. Specifically, he reverse engineered the checksum used by the Ambient F007TH.

He got onto this track after trying out the Arduino sketch written to receive the sensor’s RF communications. One peculiar part of the code turned out to be a filter for corrupt messages as the protocol’s checksum hadn’t yet been worked out. Figuring out how the checksum byte owrks wasn’t an easy process. The adventure led him to dump 13k samples into a spreadsheet to see if sorting similar sets of 5-byte message and 1-byte checksum would shed some light on the situation. The rest of the story is some impressive pattern matching that led to the final algorithm. Now [BaronVonSchnowzer] and anyone else using these modules can filter out corrupt data in the most efficient way possible.

Arduino Based PC Ambient Lighting

[royboy] from the Arduino forum has recently made a post showing off his Arduino / PC ambient light system. The system is simple to wire up and easy to use, as long as your video is being sent from a PC, which for many of us that use “home theater pc” systems is very convenient. Using a sparkfun red/green/blue (non addressable) led strip, an ULN2003A, an Arduino, and a short sketch written for processing the project is easy to toss together and very effective too.

The processing sketch continuously takes screen captures and then takes the resulting pictures and averages all the colors together. That average color is fed down to the Arduino over its stock serial connection, where it is output to 3 of the pwm capable outputs. Those outputs are connected to the 2003 Darlington transistor array to switch the 12 volt led strip.

It may seem like it would be slow, as processing is an interpreted Java based language, plus serial communication, plus Arduino overhead, but its actually very responsive and completes its task with little or no lag. Join us after the break for a quick video to see for yourself.

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Aurora Open Source Hardware Mixer


We’ve seen some fairly impressive mixer projects this year, and the Aurora mixer is no exception. It is a dual channel USB-powered mixer with two linear faders, one crossfader, eight backlit buttons and 24 potentiometers, all built around a PIC 18LF4525 microcontroller. That’s all pretty typical for a mixer, but this one is very visually attractive, featuring a clean and stylish form factor and controllable lighting both under the board and in the LEDs backlighting the buttons and knobs.

Whether you want to buy one now or build one yourself, the Aurora team has made both possible. You can contact them for pricing if you are ready to buy. If you prefer to build, this is an open source project with full assembly instructions, schematics, drivers, patches and all other source code and information you should need available here. See more photos of the Aurora mixer here, or see it in action after the break.

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LED Ambient Light Strips


[Shadow] sent in his ambient LED strip project. He picked up a ton of RGB (Red/Green/Blue) LEDs off of eBay and built several LED strips. To get up and running, he used an LED-wiz controller. With the off the shelf controller, this is a pretty easy project, and the ambient lighting effect looks great. Check out the video after the break or on the project page.

In 2006, we posted about [rafkep]’s similar ambient lighting project.

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