Hackaday Links: Remember, Remember

Buckle up, buttercup because this is the last weekly Hackaday Links post you’re getting for two weeks. Why? We have a thing next weekend. The Hackaday Superconference is November 11th and 12th (and also the 10th, because there’s a pre-game party), and it’s going to be the best hardware con you’ve ever seen. Don’t have a ticket? Too bad! But we’ll have something for our Internet denizens too.

So, you’re not going to the Hackaday Supercon but you’d like to hang out with like-minded people? GOOD NEWS! Barnes & Noble is having their third annual Mini Maker Faire on November 11th and 12th. Which Barnes & Noble? A lot of them. Our reports tell us this tends to be geared more towards the younger kids, but there are some cool people doing demonstrations. Worst case scenario? You can pick up a copy of 2600.

PoC || GTFO 0x16 is out! Pastor Laphroaig Races The Runtime Relinker And Other True Tales Of Cleverness And Craft! This PDF is a Shell Script That Runs a Python Webserver That Serves a Scala-Based JavaScript Compiler With an HTML5 Hex Viewer; or, Reverse Engineer Your Own Damn Polyglot.

In, ‘Oh, wow, this is going to be stupid’ news, I received an interesting product announcement this week. It’s a USB C power bank with an integrated hand warmer. Just think: you can recharge your phone on the go, warm your hands in the dead of winter, and hope your random battery pack from China doesn’t explode in your pocket. I’m not linking to this because it’s that dumb.

You can now cross-compile ARM with GCC in Visual Studio.

The iPhone X is out, and that means two things. There are far too many YouTube videos of people waiting in line for a phone (and not the good kind), and iFixit did a teardown. This thing is glorious. There are two batteries and a crazy double-milled PCB stack with strange and weird mezzanine connectors. The main board for the iPhone X is completely unrepairable, but it’s a work of engineering art. No word yet on reusing the mini-Kinect in the iPhone X.

Speaking of irreparable computers, the Commodore 64 is not. [Drygol] recently came across a C64 that was apparently the engine controller for a monster truck found on the bottom of the ocean. This thing was trashed, filled with rust and corrosion, and the power button just fell off. Prior to cleaning, [Drygol] soldered a new power button, bowered it up, and it worked. The crappiest C64 was repairable. A bit of cleaning, painting the case, and the installation of an SD2IEC brought this computer back to life, ready for another thirty years of retrogaming and BASIC.

The Zynq from Xilinx is one of the most interesting parts in recent memory. It’s a dual-core ARM Cortex A9 combined with an FPGA with a little more than a million reconfigurable gates. It’s been turned into a synth, a quadcopter, all of British radio, and it’s a Pynq dev board. Now there’s a new part in the Zynq family, an RFSoC that combines the general ARM/FPGA format with some RF wizardry. It’s designed for 5G wireless and radar (!), and one of those parts we can’t wait to see in use.

Do you keep blowing stuff up when attaching a USB to UART adapter to a board? Never fear, because here’s one with galvanic isolation. This is done with a neat digital isolator from Maxim

Lethal LED Lantern Leaks Lotsa ‘Leccy

When you take an item with you on a camping trip and it fails, you are not normally in a position to replace it immediately, thus you have the choice of fixing it there and then, or doing without it. When his LED camping lantern failed, [Mark Smith] was in the lucky position of camping at a friend’s compound equipped with all the tools, so of course he set about fixing it. What he found shocked him metaphorically, but anyone who handles it while it is charging can expect the more literal variation.

The lamp was an LED lantern with built-in mains and solar chargers for its Ni-Cd battery pack, and a USB charger circuit that provided a 5 volt output for charging phones and the like. The problem [Mark] discovered was that the mains charger circuit did not have any mains isolation, being a simple capacitive voltage dropper feeding a rectifier. These circuits are very common because they are extremely cheap, and are perfectly safe when concealed within insulated mains-powered products with no external connections. In the case of [Mark]’s lantern though the USB charging socket provided that external connection, and thus access to a potential 120 VAC shock for anyone touching it while charging.

Plainly this lamp doesn’t conform to any of the required safety standards for mains-powered equipment, and we’re guessing that its design might have come about by an existing safe lamp being manufactured with an upgrade in the form of the USB charger. The write-up gives it a full examination, and includes a modification to safely charge it from a wall-wart or similar safe power supply. Definitely one to watch out for!

If you were wondering what the fault was with Mark’s lamp, it was those cheap NiCd batteries failing. He replaced them, but there are plenty of techniques to rejuvenate old NiCds, both backyard, and refined.

The Shocking Truth About Transformerless Power Supplies

Transformerless power supplies are showing up a lot here on Hackaday, especially in inexpensive products where the cost of a transformer would add significantly to the BOM. But transformerless power supplies are a double-edged sword. That title? Not clickbait. Poking around in a transformerless-powered device can turn your oscilloscope into a smoking pile or get you electrocuted if you don’t understand them and take proper safety precautions.

But this isn’t a scare piece. Transformerless designs are great in their proper place, and you’re probably going to encounter one someday because they’re in everything from LED lightbulbs to IoT WiFi switches. We’re going to look at how they work, and how to design and work on them safely, because you never know when you might want to hack on one.

Here’s the punchline: transformerless power supplies are safely useable only in situations where the entire device can be enclosed and nobody can accidentally come in contact with any part of it. That means no physical electrical connections in or out — RF and IR are fair game. And when you work with one, you have to know that any part of the circuit can be at mains voltage. Now read on to see why!

Continue reading “The Shocking Truth About Transformerless Power Supplies”

Galvanic Isolated FTDI Board Saves Your USB Ports

Isolated FTDI circuitg

We work with some dangerous circuits in the pursuit of cool hacks. High voltage, high current, all demand some respect. We can protect our bodies easily enough, but what about that fancy new laptop or Macbook? [David] is here to help with his isolated versatile FTDI circuit.

Our computers are often wired directly into the circuits we’re hacking on. In days past that might have been a parallel or serial port. Today it’s almost always USB, specifically serial over USB. USB has some safety features built-in, such as current limiting. However, it isn’t too hard to blow up a USB port, or even a motherboard with high voltage. Galvanic isolation is a method of removing any electrical connection between two circuits. Connections can still be made through optical, magnetic, or capacitive methods, just to name a few. One of the simplest methods of galvanic isolation is the humble optocoupler.

Isolating a high-speed USB connection can get somewhat complex. [David] wisely chose to isolate things on the serial side of the FTDI USB to serial converter. He started with SparkFun’s open source FTDI Basic Breakout. Galvanic isolation is through either an Analog Devices ADuM 1402 or ADuM 5402. The 1402 needs a bit of power on the isolated side, while the 5402 includes an isolated DC/DC converter to provide up to 60mA.

[David] didn’t just stop at galvanic isolation. He also added ESD protection, over current protection, and multiple options which can be selected when the board is built. Nice work [David]! Now we don’t have to worry about our laptop frying when we’re blowing up wires.