Although e-paper displays are famous for being low-power and lasting essentially forever if not damaged physically, the recent push to drive even cheaper e-paper displays at a framerate like 30 FPS for a decent monochrome gaming experience does raise a few questions. The first being what this does to the power usage of these displays, and the second whether this will wear out the display in short order. To investigate this, [Bo Made It] set up a few experiments.

Subject of this test was a Waveshare ESP32-S3-ePaper board, which had previously been demonstrated running a Game Boy emulator at 30 FPS. With this software running, the board consumed on average about 115 mA, which would run down the device’s 400 mAh battery in about 3.5 hours. From here key was to isolate the power consumption of the display itself, with the system minus the display updates consuming about 90 mA.

Running the frame calculations for the greyscale mode without rendering to the screen pushed that up to 107.6 mA, with even in the 30 FPS greyscale mode the display thus only consuming about 7.4 mA, which is vanishingly small. Clearly the low-power claims of e-paper remain intact even at higher framerates.

As for lifespan, one datasheet gives the typical lifespan as one million updates. This would translate to about 9.3 hours at 30 FPS, though that assumes a full display refresh. Since a smart driver only updates changed pixels, obviously this will be longer, but the question is how much longer, and what will degradation look like?

After running 2.16 million frames of a custom endurance test featuring repeating patterns, some ghosting was apparent, but repeated refreshing made this go away again. This means that so far no permanent damage has been detected within the no doubt conservative limit provided by e-paper manufacturers.

It should be noted that Waveshare itself also recommends against running such high-FPS applications on their device, meaning that this is definitely one big longevity experiment. If actual damage occurs, this means that obviously this won’t be covered under any warranty.

We are surrounded by evolving algorithms and AI models, and it feels like we have to evolve to them as well. Of course, the world itself is always evolving, and when we have to implement filtering circuits based on current environments it might not last all that long. [Saikarthik Ramakrishnan] realized that this phenomenon can easily apply to simple RC circuits, so why not make them adapt to the changing world itself? This is exactly what the Darwin Board is meant to do: act like an evolving simple RC circuit for whatever environment or signal you want gone.

RC circuits are normally considered to be relatively simple in the world of circuits; however, the real world isn’t always all that simple. This simple evolutionary algorithm implemented by [Saikarthik Ramakrishnan] attempts to apply similar principles used in other evolving models to the humble RC circuit. Based on an ESP32, the Darwin Board is a fairly simple model of 2040 possible combinations of genomes. Yes, each possible RC circuit is its own genome, which allows simple evolution from one to another based on current requirements.

You should certainly consider checking out the project’s GitHub repository here to try out the mutating circuit itself. While this project might complicate what is normally fairly simple, there is sometimes beauty in simplicity. So why not use a comically simple circuit for a smart home feature?

USB-C Power Delivery (PD) has been a boon to anyone working with low-voltage DC power, because at a stroke it replaces a vast array of wall warts, power supplies, and connector standards with one simple and straightforward commoditized system. But with varying capabilities between sources and sinks, it can be difficult to know what’s going on.

[Marco Tabini] has created Dr. PD, a USB -C PD protocol analyzer. It can sit between USB-C PD source and sink, or emulate a sink in order to characterize a source. It supports an impressive range of USB power protocols, and can work up to the full 48 volt/240 watt limits of the technology. The project is open source and is to be the subject of a crowdfunding campaign should you want one without the extra work.

It’s likely that many of you will have had bad experiences with cheap USB-C PD gear failing to follow standards, being unable to handle the specified current, or just plain supplying the wrong voltage. We have, and while USB-C PD is genuinely a great technology, this regrettable hardware represents its grubby underbelly. This is just the project we need on the bench in our hackerspace.

In the past we’ve written about USB-C PD as a great example of new technology done right.