Trying To Fix A GoPro Hero 10 With A No Camera Input Issue

In the search for more exciting broken electronics to repair, [Hugh Jeffreys] bought a GoPro Hero 10 for US$100 with an apparently rather common issue of no camera input, along with a cracked display. This particular camera issue is rather obvious, with just darkness where the camera’s input should appear on the display. Since [Hugh] already needed a spare display, he figured that he might as well get an even more broken GoPro Hero 10 for parts.

Another US$40 later, [Hugh] found himself the proud owner of a second GoPro, this one being water damaged and no longer turning on. Getting to the internals requires removing the glued-in display, which is even trickier than with a smartphone. By inserting a thin blade, adding solvents and not prying, you can slowly work it loose.

With two disassembled GoPros it was now possible to swap modules. After a factory reset and firmware update had failed to fix the first GoPro, the camera module from the donor unit was inserted, but this made no difference. Amusingly, after cleaning the water-damaged unit’s PCBs, it was found to be in good working condition, so ultimately the second GoPro was repaired, leaving the ‘no camera input’ issue undiagnosed.

It’s possible that a board-level repair on the first unit can address the original issue, but without schematics this would likely entail a lot of blindly poking around, in the hope of finding a damaged MLCC or other obvious fault. There is also the possibility that this is a firmware issue, with some reporting luck mashing the record button, but others disagree.

Since [Hugh] did do the firmware reset and updating steps, and even inserted a whole new working camera module, it would seem to narrow the problem down to a board-level issue. Whatever the case may be, it’s a frustrating issue with a rather expensive device.

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Reverse-Engineering And Documenting The Fisher Price Pixter

Between 2000 and 2002 the Fisher Price Pixter was sold to children as an educational handheld toy with a touch screen that enabled drawing and listening to music in addition to cartridge-based games and more. It was followed up by multiple new iterations of the system, but as an ecosystem didn’t last beyond 2007. This has left much of the system in obscurity, with people like [Dmitry] doing their best to reverse-engineer, dump and document what they can, such as recently for the entire range of Pixter devices and most of the games.

One of the reasons why [Dmitri] got interested in the second-generation Pixter Color originally was as a potential PalmOS porting target, which gives somewhat of an idea of how these devices were meant to be used.

With absolutely no remaining known official documentation on how to develop software for the hardware reverse-engineering posed somewhat of a challenge. Fortunately this was made somewhat easier by the Pixter Color using the ARM-based LH7541, but worse by just how much of a minimal ARM7 implementation the SoC is. This was meant to go into a cheap-ish kid’s toy after all.

Where things got wild was that the firmware implements a 16-bit stack-based virtual machine, possibly due to initially having selected a completely different SoC. From here things get even crazier with how audio output is implemented, with [Dmitry] descending into a long-winded rant on this and all the weird things encountered during reverse-engineering.

After the Color Pixter its Multimedia sibling with slightly better SoC was also reverse-engineered, as well as the Classic device that started it all. This particular device uses an 8-bit VM, but a black-blob 6502 processor, which is rather astounding for a 2000-era device, but then again it was meant to be a toy.

In addition to getting a lot of reverse-engineering woes off his chest, [Dmitri] also details how he reverse-engineered and dumped the cartridges, as well as writing emulators to ensure that the Pixter legacy will endure, for better or worse.

Top image: Pixter with opened case. (Credit: Raimond Spekking, Wikimedia)

Making Big Dry Ice Blocks With Low Pressure CO2

Although the term ‘dry ice’ is generally used for solid CO2, it’s much more accurate to call this ‘dry snow’, as, rather than being actual solid blocks, they are effectively snow that’s been compressed really tightly. While not really necessary for most applications of dry ice, it is possible to make blocks of actual CO2 ice, and thus [Hyperspace Pirate], as someone with a healthy obsession with cold things had to make some of his own.

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Why Using Cardboard For A PC Case Is A Chore

The idea of using cardboard for a sloppy PC case isn’t new; it’s a time-honored tradition dating back to at least the 1990s. That said, with today’s CNC cutters and other advanced tooling available to hobbyists, you might be curious to see how far you can push the concept. As demonstrated in a recent video by [mryeester], the answer appears to be that good planning and a solid understanding of cardboard’s limitations are as essential as ever.

After having the PC case drawn up in CAD and cut on a professional CNC cutter by a buddy who makes commercial cardboard displays, the installation procedure for the PC components showed where a bit of foresight could have saved a lot of time and effort.

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Why You Probably Shouldn’t DIY A Car Airbag

Car airbags are both a very simple concept and a marvel of engineering, replacing the bone-shattering impact of unforgiving plastic and steel with a relatively soft landing in a funky-smelling air cushion. This deceptively simple concept requires that the gas generator activates only when there is a crash and finishes filling the airbag in the milliseconds before the squishy human’s cranium with its soft filling attempts to occupy the same space as said airbag. This makes mad Aussie bloke [Turnah81]’s attempt at DIY-ing a car airbag a most daring proposition.

Rather than messing about with an IMU and microprocessors, he went low-tech with an inertial fuel cut-off switch. These are mechanical switches that hold a steel ball in place with a magnet until a sufficiently large force — like a crash — dislodges the ball and triggers an event. Usually, a switch like this cuts off the fuel pump.

After a bit of fun with a crash-test rig and the airbag of a salvaged steering wheel, a DIY airbag was assembled using a compressed-gas cylinder instead of the fancy gas generator, along with an electrically triggered valve. Here, you can already see why modern airbags use a gas generator, as it is simply far more compact.

For the bag itself, a pillow case was adapted, with the subsequent crash test — as pictured above — going about as well as you can imagine. After this, he tried a few improvements, like using a bin liner and detonating some fuel, but it seems that the gas generator is very hard to beat for producing a large amount of gas in very little time.

Meanwhile, the inertial cut-off switch turned out to be more than sufficient for this purpose, and it was also used to trigger the original airbag. Of course, with how cheap those off-the-shelf airbag units are and are tested to be fit for purpose, you’d never DIY them for actual use in a car unless you were stark raving mad.

Airbags have a checkered history. There are some places you shouldn’t try to save costs.

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Tracing Olfactory Receptor Mapping Between The Nose And Brain

The way that the sense of smell works is that olfactory sensory neurons (OSNs) are wired up to olfactory receptors (ORs) in the nasal epithelium, from which they send signals to the brain. Once arrived there, a hierarchy of processing results in us experiencing the sensation of ‘smelling’. Exactly how the olfactory receptor-to-brain mapping works during development, and whether its physical pattern in the nasal epithelium is replicated in the brain, remained major questions until now. In a study published inĀ Cell by [David H. Brann] and others, many of these questions have now been answered, at least for mice.

As it turns out, the mapping between OSNs and ORs isn’t performed by a random selection process, but instead creates a receptor map that’s closely matched between the nasal epithelium and the brain. What has complicated answering this question up till now is that the nasal epithelium isn’t a flat surface, but a convoluted labyrinth that maximizes surface area to smell better.

The second issue was linking the physical location of OSNs and gene expression in the nasal epithelium. Using a new approach, the researchers showed an intricate patterning in this epithelium, with the basal stem cells from which it regenerates maintaining this patterning. This makes for a system very similar to, for example, the auditory system, where the detection of frequencies in the inner ear, as a linear system, is found to be replicated in the brain.

Although it does not provide us with all the answers yet about how this genetic patterning works, it offers a glimpse at a fascinating system that would seem to be used repeatedly across sensory systems. It may also provide potential treatments for medical conditions affecting the olfactory system, whereby the sense of smell is missing, reduced, or oddly miswired, for example, after a SARS-CoV-2 infection of the olfactory nerve that leads to symptoms such as a constant sensation of a burning smell.

You have to wonder if a better understanding of the nose will revive interest in digitally creating and sending smells?

The Noctua Fan Files And The Limits Of 3D Printing PC Fans

After Noctua recently released CAD files for a range of their computer fans, one of the first thoughts that popped up for most people was: Can you just to 3D print their fans? Even though Noctua begs you not to 3D print the files and even says they changed the design slightly so it wouldn’t be the same anyway, the question persists. Fortunately, [Steve] of Gamers Nexus is here to help us answer the question of whether it makes sense to 3D print a computer fan.

Unsurprisingly, the answer is mostly a resounding ‘no’. After reworking the original CAD models to be both printable on a Bambu Lab FDM printer and printing the parts in PLA, the arguably most important part, the motor, still had to be sourced from an original Noctua fan. Although you could source a cheaper motor, that could change the fan’s characteristics.

The other issue is materials. The special polymer that Noctua uses for its fans is designed not to change shape significantly when the fan blades are spinning, whereas PLA and basically every other thermoplastic will likely deform enough to hit the inside of the fan with the blades. For this reason, a 3 mm gap was used in the PLA print compared with the approximately 0.5 mm gap of the original Noctua fan.

Using the professional fan tester and semi-anechoic chamber over at Gamers Nexus, the original and replica fans were compared, showing that the 3D-printed fan had a similar noise profile but produced only about half the airflow. This is likely due to the blade shape and angle, the increased gap, and probably a dozen other details that presumably justify putting a cool $40 down for the original fan.

In short, you’re probably best off using these Noctua fan CAD models for fit testing in a larger CAD model, or 3D printing it for a similar purpose, rather than for a functional fan design. At least now we know. Thanks, [Steve].

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