Low-Power Wi-Fi Includes E-Paper Display

March 10, 2023 by Bryan Cockfield 6 Comments

Designing devices that can operate in remote environments on battery power is often challenging, especially if the devices need to last a long time between charges or battery swaps. Thankfully there are some things available that make these tasks a little easier, such as e-ink or e-paper displays which only use power when making changes to the display. That doesn’t solve all of the challenges of low-power devices, but [Albertas] shows us a few other tricks with this development board.

The platform is designed around an e-paper display and is meant to be used in places where something like sensor data needs to not only be collected, but also displayed. It also uses the ESP32C3 microcontroller as a platform which is well-known for its low power capabilities, and additionally has an on-board temperature and humidity sensor. With Bluetooth included as well, the tiny device can connect to plenty of wireless networks while consuming a remarkably low 34 µA in standby.

With a platform like this that can use extremely low power when not taking measurements, a battery charge can last a surprisingly long time. And, since it is based on common components, adding even a slightly larger battery would not be too difficult and could greatly extend this capability as well. But, we have seen similar builds running on nothing more than a coin cell, so doing so might only be necessary in the most extreme of situations.

An Instant Camera Using E-Paper As Film

February 10, 2023 by Jenny List 16 Comments

The original Polaroid cameras were a huge hit not just for their instant delivery, but for the convenient size of the permanent images they delivered. It’s something that digital cameras haven’t been able to replicate, which drew [Cameron] to produce a modern alternative. In the place of the chemical film of the original, it uses a removable e-paper display in a frame. The image is stored in the pixels of the e-paper, which can be kept as a digital version of the photograph until reattached and replaced with another freshly taken picture.

At its heart is an ESP32 with a camera, and the “film” is a Waveshare NFC e-paper module. The device is 3D printed, and manages a very creditable early-1970s aesthetic redolent of the more upmarket Polaroids of the day. Using it is as simple as pressing the button and deciding whether you like what’s on the screen. You can see it in action in the video below the break.

We like his project for its aesthetics, as well as for the very idea of using e-paper as a medium. There’s also something to be said for not having to put a Polaroid print in a clip under your armpit while it develops. Meanwhile if you do hanker for the real thing, it’s a subject we’ve looked at in the past.

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3D Printed Triptych Shows Trio Of AI-Generated Images

January 20, 2023 by Tom Nardi 11 Comments

Fascinated by art generated by deep learning systems such as DALL-E and Stable Diffusion? Then perhaps a wall installation like this phenomenal e-paper Triptych created by [Zach Archer] is in your future.

The three interlocking frames were printed out of “Walnut Wood” HTPLA from ProtoPasta, and hold a pair of 5.79 inch red/black/white displays along with a single 7.3 inch red/yellow/black/white panel from Waveshare. There are e-paper panels out there with more colors available if you wanted to go that route, but judging by the striking images [Zach] has posted, the relatively limited color palettes available on these displays doesn’t seem to be a hindrance.

Note the clever S-shaped brackets holding in the displays.

To create the images themselves, [Zach] wrote a script that would generate endless customized portraits using Stable Diffusion v1.4, and then manually selected the best to get copied over to a 32 GB micro SD card. The side images were generated on the dreamstudio.ai website, and also dumped on the card.

Every 12 hours a TinyPico ESP32 development board in the frame picks some images from the card, applies the necessary dithering and color adjustments to make them look good on the e-paper, and then updates the displays. Continue reading “3D Printed Triptych Shows Trio Of AI-Generated Images” →

An E-Ink Progress Bar For Your Unborn Child

January 13, 2023 by Tom Nardi 12 Comments

Having a child is a major milestone in a person’s life, and there’s a long list of things to get done before that little bundle of joy kicks and screams its way into the world. What better way to make sure you’ve still got time to paint the nursery and assemble the crib than to have an automated loading screen that shows just how far along the organic 3D printing process is?

This fetal development tracker was put together by [mokas] using Adafruit’s ESP32-S2 powered MagTag. As the name implies, the all-in-one electronic ink development board is designed so that it can be adhered to a metallic surface with integrated magnets. The idea is that you can pop a battery in the low-power device, stick it on your refrigerator, and have a regularly updated display of…well, whatever you want. Continue reading “An E-Ink Progress Bar For Your Unborn Child” →

Review: Inkplate 2 Shrinks Down, Adds Color

December 7, 2022 by Tom Nardi 9 Comments

Regular Hackaday readers may recall the Inkplate family of devices: open source all-in-one development boards that combine the power and versatility of the ESP32 with electronic paper displays salvaged from commercial e-readers. By taking the sharp, high-speed, displays intended for readers such as Amazon’s Kindle and bundling it together with all the hardware and software you need to make it work, the Inkplate provided a turn-key platform for anyone looking to get serious with e-paper.

Given the fact that their screens were pulled from recycled readers, it’s no surprise the previous Inkplate entries came in familiar 6 and 10 inch variants. There was even an upgraded 6 inch model that benefited from newer reader technology by adopting a touch-sensitive backlit panel, which we took a close look at last year. Their large displays make them excellent for wall mounted applications, such as a household notification center or constantly-changing art display. Plus, as you might expect, the Inkplate is an ideal choice for anyone looking to roll their own custom e-reader.

But of course, not every application needs so much screen real estate. In fact, for some tasks, such a large display could be considered a liability. Seeing a void in their existing product lineup, the folks at Soldered Electronics (previously e-radionica) have recently unveiled the diminutive Inkplate 2. This new miniature Inkplate uses the same software library as its larger predecessors, but thanks to its 2.13 inch three-color display, lends itself to a wider array of potential projects. Plus it’s considerably cheaper than the larger Inkplate models, at just $35 USD.

Considering the crowd sourced funding campaign for the Inkplate 2 blew past its goal in just 72 hours, it seems clear there’s plenty of interest in this new smaller model. But if you’re still not sure if it’s the e-paper solution you’ve been waiting for, maybe we can help — the folks at Soldered sent along a pre-production version of the Inkplate 2 for us to play around with, so let’s take it for a test drive and see what all the fuss is about.

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Driving E-Paper Displays With Memory Limited MCUs

November 21, 2022 by Tom Nardi 20 Comments

It’s easy to become jaded by modern microcontrollers: for just a few bucks you can get a MCU that’s powerful enough to give a desktop computer from the early 90s a run for its money while packing in contemporary technology like WiFi and Bluetooth. For many projects we don’t even have to consider optimizing our code, because we aren’t even scratching the surface of what the hardware is capable of.

But sometimes you don’t have the luxury of using the latest-and-greatest chip, and have to play the hand you’re dealt. That’s when folks like [Larry Bank] really shine. In a recent write-up, he goes over his experiments with driving e-paper displays (specifically, salvaged electronic shelf labels) with 8-bit MCUs that on paper shouldn’t have the resources to run them.

The problem is that these displays generally expect to be handed a fully-formed image, which can easily exceed the free RAM on a low-end chip. For example, a 1-bit 128 x 128 image would consume 2 KB of RAM — more than four times the available memory on an ATtiny85.

As [Larry] explains, his alternate approach is to write data to the display in columns that are only one byte wide. Combined with his existing work with image decompression on constrained hardware, he’s able to rapidly draw out full-screen TIFF images using an Arduino UNO as demonstrated in the video after the break. He hopes the work will inspire others to experiment with what’s possible using the dinky MCUs you generally find in second-hand shelf labels.

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Driving Three-Color E-Paper Pricetags With An Arduino

October 28, 2022 by Lewin Day 14 Comments

ePaper pricetags are becoming popular parts in the hacker community as a cheap way into tinkering with the technology. [Aaron Christophel] got his hands on a 4.4″ model with red, black, and white colors, and set about programming an ESP32 to drive the price tag instead.

The protocol the display uses was reverse-engineered by prompting the display to update via RF and monitoring the signals sent to between microcontrollers on the display’s control board. Once the protocol was understood, one of the microcontrollers could then be removed and replaced with an ESP32 for direct control. Implementing this takes some disassembly and some delicate soldering, but it’s nothing that should scare off an experienced hacker.

With the right code flashed to the ESP32, as available on Github, it’s possible to run the display directly. The hacked code does a great job driving the display, showing crisp lines and clean colors that indicate the e-Paper display is running properly.

We’ve seen [Aaron’s] work before in this area, when he hacked simpler two-color e-ink price tags. He’s also gone so far as creating entire wall displays out of salvaged displays, which is quite the sight. Video after the break.

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