Holograms Display Time With ESP32

May 5, 2023 by Bryan Cockfield 30 Comments

Holograms and holographic imagery are typically viewed within the frame of science fiction, with perhaps the most iconic examples being Princess Leia’s message to Obi-Wan in Star Wars, or the holodecks from Star Trek. In reality, holograms have been around for a surprising amount of time, with early holographic images being produced in the late 1940s. There are plenty of uses outside of imagery for modern holographic systems as well, and it’s a common enough technology that it’s possible to construct one using an ESP32 as well.

In this build, [Fiberpunk] demonstrates the construction and operation of a holographic clock. The image is three-dimensional and somewhat transparent and is driven by an ESP32 microcontroller. The display is based around a beamsplitter prism which, when viewed from the front, is almost completely invisible to the viewer. The ESP32 is housed in a casing beneath this prism, and [Fiberpunk] has two firmware versions available for the device. The first is the clock which displays an image as well as the time, and the second is more of a demonstration which can show more in-depth 3D videos using gcode models and also has motion sensing controls.

For anyone interested in holography, a platform like this is might make an excellent entry point to explore, and with the source for this build available becomes even easier. It’s almost certainly less expensive than these 3D printers that can turn out custom holographic images, and has the added benefit of being customizable and programmable as well.

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Pi Microcontroller Still Runs A Webserver

April 7, 2023 by Bryan Cockfield 14 Comments

At first glance, the Raspberry Pi Pico might seem like a bit of a black sheep when compared to the other offerings from the Raspberry Pi Foundation. While most of the rest of their lineup can run Linux environments with full desktops, the Pico is largely limited to microcontroller duties in exchange for much smaller price tags and footprints. But that doesn’t mean it can’t be coerced into doing some of the things we might want a mainline Pi to do, like run a web server.

The project can run a static web page simply by providing the Pico with the project code available on the GitHub page and the HTML that you’d like the Pico to serve. It can be more than a static web page though, as it is also capable of running Python commands through the web interface as well. The server can pass commands from the web server and back as well, allowing for control of various projects though a browser interface. In theory this could be much simpler than building a physical user interface for a project instead by offloading all of this control onto the web server instead.

The project not only supports the RP2040-based Raspberry Pi Pico but can also be implemented on other WiFi-enabled microcontroller boards like the ESP8266 and ESP32. Having something like this on hand could greatly streamline smaller projects without having to reach for a more powerful (and more expensive) single-board computer like a Pi 3 or 4. We’ve seen some other builds on these boards capable of not only running HTML and CSS renderers, but supporting some image formats as well.

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Magic 8 Ball Provides Tech Support

March 28, 2023 by Bryan Cockfield 15 Comments

ChatGPT might be making the news these days for being able to answer basically any question it’s asked, those of us who are a little older remember a much simpler technology that did about the same thing. The humble “Magic 8 Ball” could take nearly the same inputs, provided they were parsed in simple yes/no form, and provide marginal help similar to the AI tools of today. For a toy with no battery or screen, this was quite an accomplishment. But the small toy couldn’t give specific technical support help, so [kodi] made one that can.

The new 8 Ball foregoes the central fluid-filled chamber for an STM32 Blue Pill board with a few lithium batteries to power it. The original plastic shell was split in two with a hacksaw and fitted with a 3D printed ring which allows the two halves to be reconnected and separated again when it needs to charge. It uses a circular OLED to display the various messages of tech support, which are displayed when an accelerometer detects that the toy has been shaken.

Granted, most of the messages are about as helpful to solving a tech support issue as the original magic 8 Ball’s would have been, but we appreciate the ingenuity and carefree nature of a project like this. It also did an excellent job at operating in a low-power state as well, to avoid needing to charge it often. There have been a few other digital conversions of these analog fortune tellers as well, like this one which adds GIFs to each of the original answers.

New Part Day: TI Jumps In To The Cheap MCU Market

March 21, 2023 by Jenny List 75 Comments

One of the interesting areas in the world of new parts recently has been at the lower end of the microcontroller market. Not because the devices there have new capabilities or are especially fast, but because they are cheap. There are now quite a few parts from China under 10 cents apiece, but have the Western manufacturers been able to follow suit? Not quite, but Texas Instruments has a new line of ARM Cortex M0+ parts that get under 40 cents in volume in their cheapest form.

That bottom-of-the-range chip is the MSPM0L1105, a single-core 32 MHz part with 32k of Flash and 4k of RAM. It’s got all the usual peripherals you’d expect on a small microcontroller, but the one which made our heads turn was the on-board 1.45-Msps ADC. On a cheap chip, that’s much faster than expected.

So there’s another microcontroller, and it’s not as cheap as some of its competition, so what? Aside from that ADC there are several reasons to be interested, it has TI’s developer support if you’re in that ecosystem, and inevitably it will find its way on to the dev boards and SBCs we use in our community. It remains to be seen how it will fare in terms of the chip shortage though.

Meanwhile, here’s a reminder of that cheaper competition.

Thanks to the several friends who delivered this tip.

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.

A CH32V003 Toolchain — If You Can Get One To Try It On

March 2, 2023 by Jenny List 40 Comments

We’re in an exciting time for cheap microcontrollers, as with both the rise of RISC-V and the split between ARM and its Chinese subsidiary, a heap of super-cheap and very capable parts are coming to market. Sometimes these cheap chips come with the catch of being difficult to program though, but for one of them the ever-dependable [CNLohr] has brought together his own open-source toolchain. The part in question is the WCH CH32V003, which is a ten-cent RISC-V part that has an impressive array of capabilities. As always though, there’s a snag, in that we’re also told that while supplies are improving this part can be hard to find. The repository is ready for when you can get them again though, and currently also contains some demo work including addressable LED driver code.

As an alternative there’s a comparable and slightly cheaper ARM-based part, the Puya PY32. It’s reckoned to be the cheapest of the flash-based microcontrollers, and like the WCH part is bearing down on the crop of one-time-programmable chips such as the famous and considerably less powerful 3-cent Padauk. This end of the market is certainly heating up a little, and from our point of view this can only mean some exciting projects ahead.

Wi-Fi Sensor For Rapid Prototyping

February 19, 2023 by Bryan Cockfield 4 Comments

There might seem like a wide gulf between the rapid prototyping of a project and learning a completely new electronics platform, but with the right set of tools, these two tasks can go hand-in-hand. That was at least the goal with this particular build, which seeks to use a no-soldering method of assembling electronics projects and keeping code to a minimum, while still maintaining a platform that is useful for a wide variety of projects.

As a demonstration, this specific project is a simple Wi-Fi connected temperature monitoring station. Based around an ESP32 and using a DS18B20 digital temperature sensor, the components all attach to a back plate installed in a waterproof enclosure and are wired together with screw-type terminal breakout boards to avoid the need for soldering. The software suite is similarly easy to set up, revolving around the use of Tasmota and ESPHome, which means no direct programming — although there will need to be some configuration of these tools.

With the included small display, this build makes a very capable, simple, and quick temperature monitor. But this isn’t so much a build about monitoring temperature but about building and prototyping quickly without the need for specialized tools and programming. There is something to be said for having access to a suite of rapid prototyping tools for projects as well, though.