Flash Programmer Shows Some Nifty Tricks

November 5, 2023 by Jenny List 12 Comments

A handy tool to have on the bench is a Flash chip programmer, and the ones based around the CH341A USB bus converter chip are readily available. But the chip is capable of so much more than simply programming nonvolatile memory, so [Tomasz Ostrowski] has created a utility program that expands its capabilities. The software provides easy access to a range of common i2c peripherals. He’s got it talking to smart batteries, GPIOs, environmental sensors, an OLED display, and even an FM radio module. The code can all be found in a GitHub repository. The software is Windows-only so no fun and games for Linux users yet — but since it’s open source, new features are just a pull request away.

The CH341A is much more than an i2C controller, it also supports a surprising range of other interfaces including SPI, UARTs, and even a bidirectional parallel printer port. Maybe this software will serve to fire the imagination of a few others, and who knows, we could see more extended use of this versatile chip. Oddly we’ve featured these programmer boards before, though in a tricky flashing job.

Just How Dodgy Are Cheap USB Chargers Anyway?

November 3, 2023 by Dan Maloney 49 Comments

Aside from apparently having both the ability to reproduce on their own and simultaneously never being around when you need one, USB chargers seem innocuous enough. The specs are simple: convert mains voltage to 5 volts, and don’t kill anyone while doing it. Both specs are typically met by most designs, but judging by [DiodeGoneWild]’s latest USB charger teardown, the latter only just barely, and with a whole lot of luck.

The sad state of plug-in USB power supplies is one of [DiodeGoneWild]’s pet gripes, and deservedly so. Most USB chargers cram a lot of electronics into a mighty small volume, and are built to a price point, meaning that something has to give in the design. In the case of the two units he tears apart in the video below, it’s pretty clear where the compromises are. Neither unit met the specs on the label in terms of current supplied and voltage regulation, even the apparently more capable quick charger, which is the first to go under the knife. The PCB within holds some alarming surprises, like the minimal physical isolation between the mains part of the circuit and the low-voltage section, but the real treat is the Schottky diode that gets up to 170°C under full load. Safety tip: when you smell plastic burning, throw the thing out.

The second charger didn’t fare any better; although it didn’t overheat, that’s mainly because it shut itself off before it could deliver a fraction of its rated 1 amp output. The PCB construction was shoddy in the extreme, with a squiggly trace standing in for a proper fuse and a fraction of a millimeter separation between primary and secondary traces. The flyback transformer was a treat, too; who doesn’t want to rely on a whisper-thin layer of cheap lacquer to keep mains voltage out of your phone?

All in all, these designs are horrible, and we have to thank [DiodeGoneWild] for the nightmares we’ll have whenever we plug into one of these things from now on. On the other hand, this was a great introduction to switch-mode power supply designs, and what not to do with our own builds. Continue reading “Just How Dodgy Are Cheap USB Chargers Anyway?” →

A Network Adapter Thinks It’s A CD-ROM. Restore Its True Calling!

November 2, 2023 by Jenny List 32 Comments

A mildly annoying trend over recent years has been for USB hardware devices to expose a CD-ROM drive containing their drivers for Windows users. Of course there’s no real CD in there, instead the software lives on a piece of flash memory. It’s usually not a problem as they also appear on the USB bus as their true calling, but not always.

[Martijn Braam] found himself the lucky owner of a USB network adapter which seemed to see its only purpose in life to be such a drive, and since he wasn’t anxious to make another piece of e-waste, he broke it open to see if the fake CD drive could be disabled.

Inside the flimsy case he found a CoreChips SR9700 Ethernet controller, a chip for which there seems to be very little data in the wild. On the underside of the PCB was a flash chip, and as expected disabling this caused the CD drive to disappear to be replaced by the expected network card.

It’s a simple but useful hack, but there’s a little bonus for those unaware in the write-up. There’s a piece of software called USB_modeswitch that can perform this task on many cards, which is worth storing away in the event that it’s needed.

Impostor Syndrome: It’s Not Your Fault!

October 28, 2023 by Elliot Williams 68 Comments

[Crispernaki] and I have something in common. We both saw this awesome project that made a scroll wheel out of a VHS head back in 2010, and wanted to make one. We both wanted to put our own spin on the gadget, (tee-hee), discovered that it was harder than either of us wanted to commit to, and gave up.

Flash forward about a million Internet years, and [crispernaki] finally made his and wrote it up. The only problem is that it was too easy. In 2010, making USB gadgets was a lot more involved than it is today. (Back then, we had to chisel device descriptors on stone tablets.) Nowadays, the firmware is just a matter of importing the right library, and the hardware is a magnetic rotation sensor breakout board, a magnet, and super glue. Cheap, and easy.

All of this led our hero to feeling insecure. After all, a hack that beat him a dozen years ago turned out to be dead easy today. Maybe it was too easy? Maybe he wasn’t a “real” hacker? These are the signs of impostor syndrome – that feeling that just because you aren’t the world’s best, or climbing the highest mountain, or hacking the hardest project, you’re not worthy.

Well, listen up. Impostors don’t finish projects, and impostors don’t write them up to share with all the rest of us. By actually doing the thing – hacking the hack – all chances of being a fake are ruled out. The proof is sitting there on your desk, in all its Altoids-tin glory.

And it’s not your fault that it was too easy this time around. You can’t do anything to turn back the hands of time, to make the project any harder these days, or to undo the decade of hacker technical progress on the software side, much less change the global economy to make a magnetic sensor unobtainable again. The world improved, you got your hack done, and that’s that. Congratulations! (Now where do I buy some of those on-axis magnets?)

PC Fan Controller Works On Most Operating Systems

October 27, 2023 by Bryan Cockfield 13 Comments

For better or worse, most drivers for PC-related hardware like RGB components and fan controllers are built for Windows and aren’t generally of the highest quality. They’re often proprietary and clunky, and even if they aren’t a total mess they generally won’t work on Linux machines at all, or even on a headless setup regardless of OS. This custom fan controller, on the other hand, eschews the operating system almost entirely in favor of an open source fan controller board that can be reached over a network instead.

The project’s creator, [Sasa Karanovic], experimented with fan splitters to solve his problems, but found that these wouldn’t be the ideal solution given the sheer number of fans he wanted in his various computers, especially in his network-attached storage machine. For that one he wanted ten fans, with control over them in custom groups that would behave in certain ways depending on what the computer was doing. His solution uses two EMC2305 five-fan controller chip which communicates over I2C on a custom PCB with a RP2040 at the center. This allows the hardware to communicate with USB to the host computer for updating firmware and controlling over the network. There’s also a 1-wire and I2C bus exposed in case any external sensors need to be integrated into this system as well. To get power for all of those fans, the board uses a SATA connector to get power from the computer’s power supply.

With the PCB built and all of the connections to the host computer made, the custom board is able to control up to 10 fans in any custom configuration without needing a monitor or a driver since it is accessible over the network through an API. It’s also open-source so any changes to the firmware or hardware can easily be made for most air-cooled PC situations. If you’re less concerned about the internal case temperature and more concerned about all the heat your PC is dumping into a living space, you might want to look into venting your PC outside instead.

Continue reading “PC Fan Controller Works On Most Operating Systems” →

Using Industrial CT To Examine A $129 USB Cable

October 24, 2023 by Dan Maloney 77 Comments

What in the world could possibly justify charging $129 for a USB cable? And is such a cable any better than a $10 Amazon Basics cable?

To answer that question, [Jon Bruner] fired up an industrial CT scanner to look inside various cables (Nitter), with interesting results. It perhaps comes as little surprise that the premium cable is an Apple Thunderbolt 4 Pro USB-C cable, which sports 40 Gb/s transfer rates and can deliver 100 Watts of power to a device. And it turns out there’s a lot going on with this cable from an engineering and industrial design perspective. The connector shell has a very compact and extremely complex PCB assembly inside it, with a ton of SMD components and at least one BGA chip. The PCB itself is a marvel, with nine layers, a maze of blind and buried vias, and wiggle traces to balance propagation delays. The cable itself contains 20 wires, ten of which are shielded coax, and everything is firmly anchored to a stainless steel shell inside the plastic connector body.

By way of comparison, [Jon] also looked under the hood at more affordable alternatives. None were close to the same level of engineering as the Apple cable, ranging as they did from a tenth to a mere 1/32nd of the price. While none of the cables contained such a complex PCB, the Amazon Basics cable seemed the best of the bunch, with twelve wires, decent shielding, and a sturdy crimped strain relief. The other cables — well, when you’re buying a $3 cable, you get what you pay for. But does that make the Apple cable worth the expense? That’s for the buyer to decide, but at least now we know there’s something in there aside from Apple’s marketing hype.

We’ve seen these industrial CT scanners used by none other than [Ken Shirriff] and [Curious Marc] to reverse engineer Apollo-era artifacts. If you want a closer look at the instrument itself, check out the video below

Continue reading “Using Industrial CT To Examine A $129 USB Cable” →

USB-C Power For Ham Radio

September 5, 2023 by Bryan Cockfield 28 Comments

Even though manufacturers of handheld ham radios have been busy adding all sorts of bells and whistles into their portable offerings, for some reason, many of them lack a modern USB-C port. In the same vein, while some have USB for programming or otherwise communicating between the radio and a computer, very few can use USB for power. Instead , they rely on barrel jacks or antiquated charging cradles. If you’d like to modernize your handheld radio’s power source, take a look at what [jephthai] did to his Yaesu.

In the past, USB ports could be simply soldered onto a wire and used to power basically anything that took 5 VDC. But the radio in question needs 12 volts, so the key was to find a USB-C cable with the built-in electronics to negotiate the right amount of power from USB-PD devices. For this one, [jephthai] cut the barrel connector off his radio’s power supply and spliced in some Anderson power pole connectors so he could use either the standard radio charger or one spliced onto this special cable.

With this fairly simple modification out of the way, it’s possible to power the handheld radio for long outings with the proper USB battery bank on hand. For plenty of situations this is much preferable to toting around a 12 V battery, which was the method of choice for powering things like QRP rigs when operating off-grid.