Get Your ESP32 Sunny Side Up With This Solar Dev Board

July 13, 2026 by Tyler August 15 Comments

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.

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A Custom Zigbee Touch Keypad

June 26, 2026 by Zoe Skyforest 8 Comments

[Dominic Buchstaller] wanted a neat, tidy entryway keypad that actually looked good. Prime goals were something slim, wireless, and with no visible screws. Dependency on the cloud was also a no-go. With few ready-to-go options available on the market, he set about whipping up his own.

The heart of the build is an ESP32-C6 microcontroller devboard. This device has the benefit of including Zigbee communication functionality baked right into the chip. It’s hooked up to an MPR121 capacitive touch controller, which allows different segments of the touchpad PCB to act as capacitive buttons for numerical entry. The number labels are directly printed on the PCB solder mask, so there’s no overlay or other label required on top. Power is courtesy of a 1300 mAh lithium-polymer cell which gives a useful lifespan of six months between recharges. A simple 3D-printed case holds everything together and completes the clean and simple look. [Dominic] notes that it’s possible to also use the device via Matter or Thread without a lot of changes, as the ESP32-C6 can easily handle those protocols, too.

If you’re looking for a cheap, handsome keypad for your Home Assistant setup or similar, you might find this useful. We’ve explored DIY keypad entry systems before, too. If you’ve come up with some other creative way to get into your house, car, or bank vault, be sure to notify us via the tipsline.

A BIOS For Your ESP32-C6

June 23, 2026 by Jenny List 24 Comments

An old-style PC BIOS served the function of a bootloader in loading the operating system kernel, and of an API in providing a set of standard system calls through which software could interact with the hardware. Though it as been long-ago superseded by operating system level calls and UEFI bootloaders, it was a simple and easy-to-understand firmware for the PCs of the day.

Microcontrollers usually don’t have anything quite like a BIOS because their software is more often compiled as-is without the need for one. But here’s [Rompass] who has bucked that trend, with a BIOS for the ESP32-C6.

Of course this isn’t the PC BIOS we all know, and you’ll not be running DOS on it. Instead it’s a subsystem that serves the purposes outlined above and provides an environment for dynamically loaded executables from RAM rather than an operating system kernel. The executables are compiled in the normal way for the ESP32, and can be loaded over the network if necessary.

We don’t know how popular a firmware like this one will become, but for us it’s symptomatic of how the line between a microcontroller and a microprocessor is becoming blurred. The next few years are going to continue this trend, as inexpensive microcontroller application processors such as the C6’s P4 bigger brother move into the mainstream.

Header image: Popolon, CC BY-SA 4.0.

Passive Bug Zapper Tracks Its Kill Count

May 23, 2026 by Julian Scheffers 32 Comments

If it’s summer in a warm, humid climate, bugs can be the bane of your existence. A natural solution is to place a passive bug zapper to catch bugs at night. But what if that isn’t fancy enough? [Nicolas Boichat] spices it up with a passive bug zapper that tracks its kill count.

But how exactly do you detect a bug zap? With an antenna, of course! When a bug gets caught, it arcs, creating an electromagnetic pulse. A small loop antenna on the backside of the zapper receives the signal.
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Poking At The ESP32-P4 And -C6 Dies In An ESP32-P4-M3 Module

February 19, 2026 by Maya Posch 7 Comments

The RF section of the ESP32-C6 die. (Credit: electronupdate, YouTube)

With the ESP32-P4 not having any wireless functionality and instead focusing on being a small SoC, it makes sense to combine it with a second chip that handles features like WiFi and Bluetooth. This makes the Guition ESP32-P4-M3 module both a pretty good example of how the P4 will be used, and an excellent opportunity to tear into, decap and shoot photos of the dies of both the P4 and the ESP32-C6 in this particular module, courtesy of [electronupdate]. There also the blog post for those who just want to ogle the shinies.

After popping the metal shield on the module, you can see the contents as in the above photo. The P4 inside is a variant with 32 MB of PSRAM integrated along with the SoC die. This results in a die shot both of this PSRAM and the P4 die, though enough of the top metal seems to remain to clearly see the latter.

The Boya brand Flash chip is quite standard inside, and along with a glance at the inside of one of the crystal oscillators we get to glance at the inside of the C6 MCU. This is a much more simple chip than the P4, with the RF section quite obvious. The total die sizes are 2.7 x 2.7 mm for the C6 and 4.29 x 3.66 mm for the P4.

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A Brain Transplant For A Philips Smart Lamp

May 14, 2025 by Tyler August 25 Comments

As the saying goes, modern problems require modern solutions. When the modern problem is that your smart light is being hijacked by the neighbors, [Wejn]’s modern solution is to reverse engineer and replace the mainboard.

The light in question is a Phillips Hue Ambiance, and [Wejn]’s excellently-documented six part series takes us through the process of creating a replacement light driver. It’s a good read, including reverse-engineering the PWM functions to get the lights to dim exactly like stock, and a dive into the Zigbee protocol so his rebuild light could still talk to the Philips Hue hub. The firmware [Wejn] wrote for the ESP32C6 he chose to use for this project is on GitHub, with the PCB in a second repo.

We want to applaud [Wejn] for his excellent documentation and open-sourcing (the firmware and PCB are under GPL v3). Not only do we get enough information to replicate this project perfectly if we so choose, but by writing out his design process, [Wejn] gives everyone reading a good head start in doing something similar with other hardware. Even if you’re scratching your head wondering why a light switch isn’t good enough anjymore, you have to appreciate what [Wejn] is offering the community.

We’ve covered domestic brain transplants in the past — which is easier in this sort of light than the close confines of a smart bulb. If you’re still wondering why not just use a light switch, perhaps you’d rather hack the light to run doom instead.

Before you go, can we just take a moment to appreciate how bizarre the world has become that we have a DOOM-capable computer to run fancy light fixture? If you’re using what might have been a decent workstation in days of yore to perform a painfully mundane task, let us know on the tips line.

Hybrid Mechanical Clock Shows It Both Ways

April 1, 2025 by Tom Nardi 16 Comments

After seeing some of the interesting clock builds we’ve featured recently, [shiura] decided to throw their hat in the ring and sent us word about their incredible 3D printed hybrid clock that combines analog and digital styles.

While the multiple rotating rings might look complex from the front, the ingenious design behind the mechanism is powered by a single stepper motor. Its operation is well explained in the video below, but the short version is that each ring has a hook that pushes its neighboring ring over to the next digit once it has completed a full rotation. So the rightmost ring rotates freely through 0 to 9, then flips the 10-minute ring to the next number before starting its journey again. This does mean that the minute hand on the analog display makes a leap forward every 10 minutes rather than move smoothly, but we think its a reasonable compromise.

Beyond the 28BYJ-48 geared stepper motor and its driver board, the only other electronics in the build is a Seeed Studio XIAO ESP32C6 microcontroller. The WiFi-enabled MCU is able to pull the current time down from the Internet, but keep it mind it takes quite awhile for the mechanism to move all the wheels; you can see the process happen at 60x speed in the video.

If you’re looking to recreate this beauty, the trickiest part of this whole build might be the 3D print itself, as the design appears to make considerable use of multi-material printing. While it’s not impossible to build the clock with a traditional printer, you’ll have to accept losing some surface detail on the face and performing some well-timed filament swaps.

[shirua] tells us they were inspired to send their timepiece in after seeing the post about the sliding clock that just went out earlier in the week.

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