How Long Can A Quadcopter Drone Fly On Just Solar?

March 20, 2026 by Maya Posch 34 Comments

The final second prototype flying. (Credit: Luke Maximo Bell, YouTube)

The dream of fully powering everything from aircraft to cars on just the power generated from solar panels attached to the machine remains a tempting one, but always seems to require some serious engineering including putting the machine on a crash diet. The quadcopter that [Luke Maximo Bell] tried to fly off just solar power is a good case in point, as the first attempt crashed after three minutes and wrecked its solar panels. Now he’s back with a second attempt that ought to stay airborne for as long as the sun is shining.

Among the flaws with the first prototype were poor support for the very thin and fragile PV panels, requiring much better support on the carbon fiber frame of the drone. To support the very large solar array, the first drone’s arms were made to be very long, but this interfered with maneuvering, so the second version got trimmed down and the array raised above the frame. This saved 70 grams of weight from the shortened tubs, which could then be added to the new panel supports.

After an initial test flight resulted in a crash when the PV output dropped, the need for a small battery buffer was clear, so this was added, along with a reduction of the array to 4×7 panels to get the same 20V as the battery. The array also had to be reinforced, as the thin array was very wobbly in addition to making it impossible to fly with any significant wind.

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User Repair Of A Not User-Repairable Victron CCGX Issue

March 20, 2026 by Maya Posch 4 Comments

Power banks come in many sizes, and those that target construction sites are probably among the largest. The massive four ton unit based around lead-acid batteries which the [Buy it Fix it] YouTube channel got handed is a good example. Inside it are Victron CCGX inverters among a lot of other Victron electronics, with the control panel for the system throwing up an error that was deemed to be not user-serviceable. Naturally, this makes for a good challenge.

The exact error as thrown up on the central control panel is error #42, indicating a storage corruption issue on the device. According to the manual this means an issue with the internal flash memory that stores settings, serial numbers and WiFi credentials, requiring it to be shipped back to the manufacturer.

To further diagnose the issue, this Color Control unit was taken out of the power bank and coaxed onto a repair bench. This device has a whole host of Ethernet, CAN and other buses on the back, along with a USB host feature, but using the latter to reflash the firmware made no difference. Fortunately it’s just an embedded Linux system running on the System-on-Module and gaining remote SSH access was a snap due to easy root access.

Interestingly, running a diagnostic on the flash IC showed it to be still in good condition. Instead an ECC issue was logged that caused it to be marked as bad. This seems to have been due to the flash IC requiring 4 bits of ECC per 528 bytes, but the software using only a single bit. After reformatting and clearing the error it seems to have fixed the issue. Apparently it was just a weird configuration error that soft-bricked the device, raising the question of how that happened.

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Google Unveils New Process For Installing Unverified Android Apps

March 20, 2026 by Maya Posch 93 Comments

It’s no secret that Google really doesn’t like it that people are installing Android applications from any other source than the Play Store. Last year they proposed locking everyone into their official software repository by requiring all apps to be signed by verified developers, an identity which would be checked against a Google-maintained list. After a lot of pushback a so-called ‘advanced flow’ for installing even unsigned APKs would be implemented, and we now know how this process is supposed to work.

Instead of the old ‘allow installing from unknown sources’ toggle, you are now going to have to dig deep into the Developer Options, to tap the Allow Unverified Packages setting and confirm that nobody is forcing you to do this. This starts a ‘security delay’ of twenty-four hours after you restart the device, following which you can finally enable the setting either temporarily or permanently. It would seem these measures are in place to make it more difficult for a scammer to coerce a user into installing a malicious app — whether or not that’s a realistic concern or not, we’re not sure.

When we last covered this issue this ‘advanced flow’ had just been introduced as an appeasement option. In addition to this a limited free developer account was also pitched, which now turns out to allow for up to only 20 device installations. If you want more than this, you have to pay the $25 fee and provide your government ID.

Although Google’s public pitch is still that this is ‘for user security’, it will also mean that third-party app stores are swept up in these changes, with developers who publish on these stores subject to the same verification rules. This means that Android users will have to learn quickly how to enable this new option as it will be rolled out to more countries over the coming months.

The reality is that scammers will simply work around this issue by buying up already verified developer accounts. At the same time, it’ll cripple third-party app stores and indie developers who had intended to distribute their Android app by simply providing an APK download.

Studying A Battle Born LFP Battery’s Death Under Controlled Conditions

March 19, 2026 by Maya Posch 30 Comments

The test setup for the Battle Born LFP cycling. (Credit: Will Prowse, YouTube)

There has been quite a bit of news recently about the Battle Born LiFePO₄ (LFP) batteries and how they are dying in droves if not outright melting their plastic enclosures. Although the subsequent autopsies show molten plastic spacers on the bus bars and discolored metal in addition to very loose wiring, it can be educational to see exactly what is happening during repeated charge-discharge cycles at a fraction of the battery’s rated current. Thus [Will Prowse] recently sacrificed another Battle Born 75 Ah LFP battery to the Engineering QA Gods.

This time around the battery was hooked up to test equipment to fully graph out the charging and discharging voltage and current as it was put through its paces. To keep the battery as happy as possible it was charged and discharged at a mere 49A, well below its rated 100A.

Despite this, even after a mere 14 cycles the battery’s BMS would repeatedly disconnect the battery, as recorded by the instruments. Clearly something wasn’t happy inside the battery at this point, but the decision was made to push it a little bit harder while still staying well below the rated current.

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Teardown Of A 2026 LEGO SMART Brick

March 18, 2026 by Maya Posch 44 Comments

LEGO SMART brick from its side. (Credit: EvilmonkeyzDesignz, YouTube)

At the beginning of March this year LEGO released their new SMART brick, which looks like a 2×4 stud brick and is filled to the brim with sensors, LEDs, NFC and Bluetooth functionality, as well as a purported custom ASIC. The central idea behind it appears to be to add a lot of interactivity to LEGO builds while allowing for mesh-style communication with other SMART bricks. Naturally, this makes it a great subject for a teardown, which is what [EvilmonkeyzDesignz] over on YouTube did in a recent video.

Normally the only way you can purchase one of these new bricks is by buying them as part of a ‘Smart Play’ set, but someone was selling singular bricks on EBay. As the brick is inductively recharged, it’s pretty well-sealed, requiring a fairly destructive opening method.

Directly below the transparent top is a speaker, with the opposing PCB on the main body containing a microphone as well as a number of RGB LEDs. On the opposite side of this PCB we find the photo sensor, but to get to this part of the PCB the copper wires that wrap around the entire main assembly have to be disconnected from the PCB’s side pads with some force as they’re apparently pressed in place without the use of solder.

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Running Windows 98 On The IPAQ IA-2 Internet Appliance

March 18, 2026 by Maya Posch 10 Comments

Devices that were limited to only run a web browser were relatively common around 2000, as many people wanted to surf the Information Super Highway, but didn’t quite want to get a regular PC — being in many ways the retro equivalent of a Chromebook. The Compaq iPAQ IA-2 from 2000 that [Dave Luna] got is no exception, with a Microsoft CE-based OS that is meant to be used with Microsoft Network (MSN) dial-up, which amusingly is still available today.

In order to get a more useful OS on it, like Windows 98, you have to jump through quite a few hoops, as [Dave] found out. Although there is an IDE connection on the mainboard, this cannot be booted from, likely due to BIOS limitations. This means that he had to chain boot via the 16 MB NAND Flash drive that the original OS booted from, which was done by writing MS-DOS to the Flash drive using another workaround as it’s not a standard IDE device either.

From this you can then boot Windows 98 from an IDE drive by pretending that it’s an ATAPI IDE device to dodge a limitation on IDE devices. The system’s hardware isn’t really going to make it into a blazing fast retro computer. It only has a 266 MHz Geode GX1 CPU and supports up to 256 MB of SDRAM. The IA-2 is also limited to 800×600, which required the use of an external monitor (as seen above) hooked up to the internal VGA port to set the proper resolution in the OS.

But at least it can run DOOM, so that bare minimum requirement can be ticked off.

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Forgetfulino Puts Back Up Of Source Inside The Binary

March 18, 2026 by Maya Posch 25 Comments

How often have you pulled out old MCU-based project that still works fine, but you have no idea where the original source code has gone? Having the binary image and the source code as separate things to keep track of usually isn’t a problem, but there’s something to be said for adding the source — and documentation — to this image if you have some flash to spare. This is basically what the Forgetfulino Arduino library by [Nader Al Khatib] does.

Essentially, the library compresses the source files and assigns it to be burned onto the flash alongside the binary. There is also a bit of code added to the firmware so that this code can be retrieved via the serial port at any time, negating the need for a firmware dump and manual disassembly. For ease of use, the library has an Arduino IDE extension that automates the process. The basic idea could also be adapted to different environments should anyone wish to take up the challenge.

You probably wouldn’t want debug builds to feature this additional payload as writing it to flash will eat up time and write cycles. But for a release build that will be put out in the (literal) field for a few years or even decades, it could be very convenient. After all, you never know when that Git repository that you relied on might go AWOL.