At the Hackaday Europe conference in Italy earlier in the year, we were shown a rather interesting device. The work of [Alun Morris], it was an ESP32-powered Cheap Black Display board, and it was running a web browser. Definitely an achievement.
Lest you imagine that it was sporting the latest and greatest in browser technology, we must disappoint you. The browser in question is a very basic text mode device, but it did happily retrieve Hackaday, which should be the only test a browser should need to pass.
Under the hood it’s running FreeRTOS, with separate HTML retrieval and tokenizing, and UI processes. It can fetch web pages directly, but there’s also a server-side proxy for difficult sites, and for creating image thumbnails.
An ESP32 is a powerful microcontroller, but it’s fair to say it’s not in the league of running a web browser and as far as we can remember this is the first one we’ve seen. We’re sure it’s a field with further progress to be made though, particularly with the more powerful recent chips in the series. This project however is a good start, and more importantly it can be yours for a few dollars on Ali to buy a dev board. What are you waiting for?
At least in theory, video games are more resistant to becoming lost media thanks to their digital nature — they’re easy to copy and emulators have saved many titles that are otherwise locked in corporate vaults. But emulators give us something beyond simple preservation: they can also be used to enhance games well beyond the capabilities of the original systems while still preserving the souls of the games, as this NES emulator manages to do.
The emulator is called Anemoia-ESP32, and as its name suggests is a re-write of the Anemoia emulator specifically built for the ESP32. By modern standards these little chips don’t pack much of a punch, but compared to original NES hardware they’re more than up to the task of gaming. This project aims to recreate the Nintendo Entertainment System experience as faithfully as possible, hitting 60 FPS in most instances, as well as maintaining full audio emulation. Running on an ESP32 enables some truly small handheld options that would be difficult to achieve with more traditional platforms for emulation. There are some PCBs available here as well, but aren’t required to explore this project with.
As far as extra features compared to original NES hardware, the emulator does support save states and has a number of other settings improvements. Installation is as easy as flashing any other firmware image onto an ESP32, which these days can even be done from the browser. No word on whether or not it will eventually support emulating dual Picture Processing Units, but we can hope.
Compared to the Arduino Uno of old, modern microcontrollers are absolutely tiny — especially for the amount of processing power and I/O you get. But if you need something really small, like fits-on-the-tip-of-your-finger small, most of the turn-key development boards on the market are still a bit too big.
There are a lot of ESP32-based development boards out there– and why not? It’s a versatile chip that can be used in all sorts of situations, and people want boards to match them. Not finding one to his liking that was specifically built for solar powered IoT projects, [Narrow Studios] rolled his own. Well, designed it; like most these days, he’s outsourced the manufacturing to PCBWay, which is where you’ll need to go if you want one.
Why might you want one? Well, if you have similar goals in mind to [Narrow Studios]. He’s put an ESP32-C6 Mini on the board, which means it’s got most of the IoT communications protocols you might be interested in — bluetooth, wifi, Matter, Thread, and Zigbee, too. Ten 10 IO pins have been broken out, plus I2C on a QWIIC connector, which gets you a whole ecosystem of sensors to easily plug into. The “solar” part is justified by the inclusion of a BQ25186 linear battery charging IC from Texas Instruments, with the designated solar power input protected against reverse voltage in case you– like this author– have let magic smoke out by hooking things up backwards. Is it embarrassing? Yes. Does it happen? Also yes, so putting protection on the board is a nice feature. [Narrow Studios] released a video that we’ve embedded below discussing his design choices and demonstrating the device, but the project page can give you the gist.
Of course there’ve been plenty of solar-powered projects to feature the ESP32 here before– you can even use it for maximum power point tracking— but this dev board might be exactly what someone is looking for to build their next IoT project, so we’re thankful to [Narrow Studios] for the tip.
If you’re not aware, there is such a thing as adorable little three digit LCD 7-segment displays. They come in a ten-pin DIP package and are just begging to be integrated into a project. The catch is they are just a tiny bit weird. Luckily for us all, [Nagy Krisztián] spells out exactly how to use them.
The first odd thing about these ten-pin LCD displays is that they have a footprint that doesn’t quite mesh with standard 0.1 inch spacing, meaning they will not cleanly fit into a breadboard. Luckily, one can solve this with a bit of force. It’s a small part, and the pins don’t seem to mind.
These little LCDs are adorable, but a bit unusual to interface with.
The second odd thing is wrapping one’s head around the pin mapping. Figuring out the table of which pins activate which segments in the digits is easier if one keeps in mind that each segment of each digit is the product of two different pins. For example, “2A” is digit two, segment A, and is the product of pins 3 and COM4.
That’s not all. Electrically speaking, driving this LCD isn’t nearly as straightforward as an LED.
With an LED display, the COM pins are either common anode or common cathode, which tells one whether lighting up a segment means holding the COM pin at GND with voltage applied to the segment pin, or the other way around. But in the case of this LCD display, the polarity applied is swapped every cycle. Oh, and inactive COM pins need to held at half-voltage. Neat!
[Nagy] drives the whole thing with little more than an ATtiny84 microcontroller and a few resistors. A switchable half-voltage signal is cleverly created by combining a simple voltage divider and taking advantage of the fact that the ATtiny84’s pins can be in one of three different states depending on how they are configured: high, low, or high-impedance (pin configured as an input). Each COM pin on the display gets connected to both an ATtiny84 pin, and to the supply voltage via two resistors forming a voltage divider. When the ATtiny drives the pin high, the LCD pin sees about 3 V. When the pin is driven LOW, the LCD pin sees 0 V. When the ATtiny configures the pin as an input, the LCD pin receives about 1.5 V.
The bulk of the software is defining which pins and states equal which digits, and cycling the LCD at a rate of vaguely 60 Hz which delivers flicker-free results.
We appreciate the clever combination of voltage divider with pin configuration to create three switchable voltage levels. If you liked that and want to see more serious leveraging of pin configuration on a microcontroller, check out how to drive seven LEDs with only two pins.
The GeekMagic SmallTV is as its name suggests, a tiny, vaguely TV-styled, device with a screen, that’s sold as a desktop notifier. Depending on the firmware running on the device it can display various pieces of information, ranging from the time and weather to the current price of Bitcoin. What makes it interesting is that it supports software updates over WiFi, so [Giovi321] has made a new firmware package for it.
These things are readily available from AliExpress.
It seems there are several versions of this device, something which appears to be reflected in the prices they sell for on AliExpress. The older version runs on the ESP8266, and there’s also a ESP32-C2 variant in the wild. The firmware supports both flavors, providing stock and crypto tickers, an ADS-B tracker, and a Claude AI token usage gauge.
What gives this potential is that the various functions are clearly split out in the code, and there’s nothing to stop you pointing it at a data source of your choosing. This makes it more than a bit of cheap e-waste novelty, and we hope that others will take up the baton and do interesting things with it.
The ESSP8266 is a chip we don’t see too much of these days, having been surpassed by its ESP32 siblings. Still, someone recently gave it a simple OS.
You almost certainly don’t have an application for the sort of accurate timekeeping that’s made possible by this enhanced version of [Cristiano Monteiro]’s satellite-backed time server. By his own admission, the vast majority of users will be more than happy to have their system’s time synchronized by the traditional Network Time Protocol (NTP). But if you’re really chasing those last few microseconds, that’s where the Precision Time Protocol (PTP) comes in.
With NTP, you can get within 10 milliseconds or so of your upstream time source — but PTP is accurate down to nanoseconds. Unless you’re performing some kind of scientific research, running a robotic assembly line, or perhaps doing high-speed financial trading, there’s no reason for this level of accuracy. In fact, PTP is such a niche technology that until the release of the ESP32-P4, [Cristiano] couldn’t even find an affordable enough chip that supported it.
Hardware-level support for PTP is important as there’s no way to achieve this level of accuracy with software alone, the capability needs to be baked into the Ethernet controller. As you might expect, it takes a highly accurate time source to make the most of PTP, and that’s where the navigation-grade Global Navigation Satellite System (GNSS) receiver comes in. All told the cost of the build is unsurprisingly higher than that of its predecessor, but [Cristiano] says it’s still a couple zeros shy of what a commercial offering would run.
As with his original time server from 2021, [Cristiano] made sure this build was as friendly as possible for hackers and makers. We especially like the 3D printed case designed in OpenSCAD, and his insistence that the gadget have a front panel with blinking status LEDs. Again, the vast majority of us don’t need our clocks to be accurate down to the nanosecond…but it’s nice to know we have the option.
