Word Of The Day Calendar Is Great Use Of E-Paper

October 28, 2024 by Lewin Day 10 Comments

If you’re trying to learn a new language, there are always a lot of words to learn. A word-of-the-day calendar can help, and they’re often readily available off the shelf. Or, you can grab some hardware and build your own, as [daedal-tech] did!

The project was built as a gift to help [daedal-tech]’s partner with their efforts to pick up French. Thus, a Raspberry Pi Zero 2W was employed and paired with a small Waveshare e-Paper display. These were stuffed inside a fancy light switch plate from Hobby Lobby and a small stand, the pair of which act as a pretty nice little frame for the build. The Pi runs a small Python script which employs the BeautifulSoup4 library and the Python Image library. Basically, the script grabs French words and spits them out on the display with a small description such that one might understand their meaning.

It’s a simple build, but one that has some real utility and is fun to boot. We might see more word clocks than calendars around these parts, but we love both all the same!

CL-32: The Minimum Possible For A Useful Handheld Computer

September 1, 2024 by Jenny List 19 Comments

For almost as long as there have been microcomputers, there have been attempts with varying success to make tiny handheld microcomputers. Sometimes these have been very good, and other times they’ve missed the mark in some way. Latest to find its way to us is the CL-32 from [Moosepr], it’s a handheld computer with an ESP32 as brains, an electronic paper display, and a QWERTY keyboard in its smart printed case.

The hardware is relatively standard, save for the keyboard which is a dome-switch design in which the membrane carrying the domes is hand-made. We like this, and don’t think we’ve seen anyone else doing that. Expansion is taken care of by a novel socket arrangement in which boards nestle in a recess in the surface. Some experimentation was required as always to drive the display, but the result is a functional computer.

Sadly there’s little detail in terms of what the software will be, and no hardware files as yet. But what we can see is promising enough to make this one to watch, so we’ll look forward to what they come up with. If an ESP32 OS is a problem, there’s always badge.team, who have been continuously improving theirs since 2017.

Hands On: Inkplate 6 MOTION

June 6, 2024 by Tom Nardi 11 Comments

Over the last several years, DIY projects utilizing e-paper displays have become more common. While saying the technology is now cheap might be overstating the situation a bit, the prices on at least small e-paper panels have certainly become far more reasonable for the hobbyist. Pair one of them with a modern microcontroller such as the RP2040 or ESP32, sprinkle in a few open source libraries, and you’re well on the way to creating an energy-efficient smart display for your home or office.

But therein lies the problem. There’s still a decent amount of leg work involved in getting the hardware wired up and talking to each other. Putting the e-paper display and MCU together is often only half the battle — depending on your plans, you’ll probably want to add a few sensors to the mix, or perhaps some RGB status LEDs. An onboard battery charger and real-time clock would be nice as well. Pretty soon, your homebrew e-paper gadget is starting to look remarkably like the bottom of your junk bin.

For those after a more integrated solution, the folks at Soldered Electronics have offered up a line of premium open source hardware development boards that combine various styles of e-paper panels (touch, color, lighted, etc) with a microcontroller, an array of sensors, and pretty much every other feature they could think of. To top it off, they put in the effort to produce fantastic documentation, easy to use libraries, and free support software such as an online GUI builder and image converter.

We’ve reviewed a number of previous Inkplate boards, and always came away very impressed by the attention to detail from Soldered Electronics. When they asked if we’d be interested in taking a look at a prototype for their new 6 MOTION board, we were eager to see what this new variant brings to the table. Since both the software and hardware are still pre-production, we won’t call this a review, but it should give you a good idea of what to expect when the final units start shipping out in October.

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A Threat Level Monitor For Everyone

March 31, 2024 by Jenny List 25 Comments

A TV news pundit might on any given evening in 2024 look at the viewers and gravely announce that we are living in uncertain times. Those of us who’ve been around for a bit longer than we’d like to admit would see that, scratch our heads, and ask “Have we ever not lived in uncertain times?” If all this uncertainty is getting to you though, you can now reassure yourself as [Ian Williams] has, with a threat level monitor which displays the UK’s current ~~level of projected fear~~ threat level.

The build is fairly straightforward in hardware terms, with a Raspberry Pi Zero and a Pimoroni e-paper display pHAT. The software grabs the current level of doom from in this case the UK government’s website with a nifty bit of Python code, and turns it into an easy to read alert level bar.

So if you’re genuinely worried that the sky might fall upon your head you can now gain reassurance from a small piece of electronic hardware. If you feel things are really going south though, how about converting your basement into a fallout shelter?

Clever E-Ink Driver Does 32 Levels Of Grey, Avoids Update Flicker, And More

March 23, 2024 by Donald Papp 12 Comments

There’s a lot to like about E-Ink displays, and you might be about to like them even more with [antirez]’s MicroPython driver for the Badger 2040 (or any display based on the UC8151 / IL0373) because it brings all kinds of useful features to your next project.

E-Ink displays are great. They are high contrast, daylight-readable, and require zero power to maintain a displayed image. But a few things come with the territory: displays have slow refresh rates compared to other display types, expect flickering during screen changes, and the displays are monochrome. [Antirez]’s new driver not only provides a MicroPython interface but goes in some fantastic directions that challenge those usual drawbacks.

Probably the most striking is the ability to display greyscale images without relying on dithering, which means the results avoid the charmingly gritty look of old-school dithering. Dithering has its place, but it’s not always the best choice, so options are great.

Similarly, display flicker may be a small price to pay for some, but if the obvious flicker is too boorish and crude-looking one can use an anti-flicker refresh mode that greatly limits flickering at the cost of update speed. Over time some image ghosting will accumulate which necessitates an occasional whole-screen refresh, but the effect is overall much nicer when updating something like a clock face.

How is this all done? It turns out that the controller chips for these displays are highly configurable, and it’s possible to do much more than simply drive the display in known-good and completely approved modes. It’s also entirely possible to permanently damage one’s display by doing so. Part of what makes [antirez]’s work so appealing is that he has already done the work finding workable configurations.

His driver is designed using computed LUTs (look-up tables) that make using and exploring alternative refresh modes easy and efficient, invaluable for exploring the capabilities of a patented, poorly documented technology like E-Paper displays.

We’ve seen the Badger 2040 E-Ink display in a teapot timer and a custom macropad, and [antirez]’s uc8151_micropython project is a fantastic step forward. And don’t miss another of [antirez]’s clever microcontroller hacks: playing audio without a DAC.

ESP32 Weather Station Looks Great With Color E-Paper Display

February 28, 2024 by Lewin Day 20 Comments

[educ8s.tv] has built weather stations before, but his latest is his best yet. It’s all thanks to its low-power design, enabled by its e-paper display.

The build is based around an ESP32 microcontroller, combined with a BMP180 sensor for measuring barometric pressure, and a DHT22 sensor for measuring temperature and humidity. By taking these values and feeding them into the Zambretti algorithm, it’s possible to generate a rudimentary weather forecast.

The weather station looks particularly impressive thanks to its six-color e-paper display. It’s brightly colored and easy to read, and displays graphs of temperature, pressure, and humidity over time. Plus, by virtue of the fact that it only draws power when updating, it allows the project to last a long time running solely on battery power.

As far as DIY weather stations go, this is an attractive and clean design that offers plenty of useful data to the user. We’ve seen some other neat builds in this vein before, too.

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Custom Multi-Segment E-Ink Displays From Design To Driving

February 8, 2024 by Dan Maloney 21 Comments

With multi-segment displays, what you see available online is pretty much what you get. LEDs, LCDs, VFDs; if you want to keep your BOM at a reasonable price, you’ve pretty much got to settle for whatever some designer thinks looks good. And if the manufacturer’s aesthetic doesn’t match yours, it’s tough luck for you.

Maybe not though. [upir] has a thing for custom displays, leading him to explore custom-made e-ink displays. The displays are made by a company called Ynvisible, and while they’re not exactly giving away the unique-looking flexible displays, they seem pretty reasonably priced. Since the displays are made with a screen printing process, most of the video below concerns getting [upir]’s preferred design into files suitable for printing. He uses Adobe Illustrator for that job, turning multi-segment design ideas by YouTuber [Posy] into chunky displays. There are some design restrictions, of course, chief of which is spacing between segments. [upir] shows off some Illustrator-fu that helps automate that process, as well as a host of general vector graphics design tips and tricks.

After sending off the design files to Ynvisible and getting the flexible displays back, [upir] walks us through the details of driving them. It’s not as simple as you’d think, at least in the Arduino world; the segments need +1.5 volts with reference to the common connection to turn on, and -1.5 volts to turn off. His clever solution is to use an Arduino Uno R4 and take advantage of the onboard DAC. To turn on a segment, he connects a segment to a GPIO pin set high while sending 3.5 volts out of the DAC output into the display’s common connection. The difference between the two pins is 1.5 volts, turning the segment on. To turn it off, he drops the DAC output to 1.5 volts and drives the common GPIO pin low. Pretty clever, and no extra circuitry is required.

This isn’t the first time we’ve seen [upir] trying to jazz things up in the display department. He’s played with masking LED matrix displays with SMD stencils before, and figured out how to send custom fonts to 16×2 displays too.

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