USB Volume Control

If you buy expensive computer speakers, they often have a volume knob you can mount somewhere on your desk so you aren’t dependent on the onboard volume control. [Kris S] decided to build his own version of the remote volume control. Not surprisingly, it uses an Arduino-compatible Digispark board and a rotary controller. The Digispark (that [Kris S] bought for $2) is compatible with the Adafruit Trinket. This is key because the Trinket libraries are what make it easy to send media keys over the USB (using the HID interface) to control the volume.

Really, though, the best part of the build is the good looking knob made out of a pill bottle (see the video below). The micro Digispark is small enough to fit in the lid of the pill bottle, and some wax and pellets add some heft to the volume control. Continue reading “USB Volume Control”

The USB Killer – Now A Crowdfunding Campaign

Kickstarter, Indiegogo, and every other crowdfunding site out there frequently have projects that should never be products. The latest promises to protect you from security breaches and identity theft by blowing up your computer. It’s the USB Killer, and for only $99 USD, you too can destroy the USB port in your computer and everything else attached to it.

The USB Killer is a device that plugs into the USB port on any computer, charges up several caps, and dumps all that voltage back into the computer. The process repeats until something breaks. We’ve seen it used on a poor Thinkpad X60, and from the video evidence it does exactly what it’s designed to do: kill a computer.

The Indiegogo campaign for the USB killer comes with a web page for the campaign that goes over the function of the device in much more detail. Inside the USB killer is a DC/DC converter that charges a few capacitors to -110V. When the caps are charged, that voltage is dumped back into the USB port where something will happen. Somewhat surprisingly, the folks behind the USB Killer have a video of a computer not dying when the USB Killer is plugged in. Only killing the USB port in a computer is not a guaranteed functionality, as the Indiegogo campaign has the following disclaimer: “Please be aware: USB Killer may cause damage to the motherboard, depending on your computer. By making a pre-order you acknowledge that you are aware of this fact.”

One Dollar USB Sound Card Turned O-Scope

Using the inputs on a computer’s sound card is an old trick to fake a very simplistic, AC coupled, slow oscilloscope. You can get DC operation by desoldering a couple capacitors, but if the sound card is integrated into the motherboard it raises the stakes if you mess that up.

[TMSZ] has a better option, a ~1 dollar USB sound card which is easily hacked to work as a simple oscilloscope. Easily found on eBay, the 7.1 virtual channel sound card is identical in brains to a more expensive c-media model, but the layout of the PCB makes it easier to bypass the DC blocking caps. Software and DLL files to use the sound card with Miniscope v4 — a Windows GUI for oscilloscopes — are also linked, so getting set up should be fairly simple.

Now of course this is not lab-grade measurement equipment: the sampling rate is limited to 44KHz and the voltages must be in the typical “line level” range, under two volts. If you don’t mind a little extra noise, you can increase the input impedance with a single resistor. This extends the input range up to six volts, which covers most hobby and microcontroller usage.

So if you’re really in need of a scope, but only have a buck to spend, this may be just the hack for you! Those willing to shell out a hefty sum for a high-end headless oscilloscope should look onto the virtual bench.

The USB Killer, Version 2.0

There are a lot of stupid things you can do with the ports on your computer. The best example is the Etherkiller, an RJ45 plug wired directly to a mains cable. Do not plug that into a router. USB is a little trickier, but with a sufficient number of caps, anyone can build a USB killer that will fry any computer (.ru, Google Translatrix)

The USB Killer v2.0 is [Dark Purple]’s second version of this device. The first version was just a small board with a DC/DC converter, a few caps, and a FET. When plugged in to a computer, the converter would charge the caps up to -110V, dump that voltage into the USB signal wires, and repeat the entire process until the computer died. This second version is slightly more refined, and it now dumps -220V directly onto the USB signal wires. Don’t try this at home.

So, does the device work? Most definitely. A poor Thinkpad X60 was destroyed with the USB killer for purposes of demonstration in the video below. This laptop was originally purchased just for the test, but the monster who created the USB killer grew attached to this neat little laptop. There’s a new motherboard on the way, and this laptop will live again.

Continue reading “The USB Killer, Version 2.0”

Hacklet 79 – USB Projects

Universal Serial Bus was created to simplify interconnecting computers and peripherals. First released in 1996, hackers and makers were slow to accept this strange new protocol. Parallel and serial ports were simpler, worked great, and had decades of hacking with thousands of projects behind them. As the new standard caught on in the mainstream, RS-232 and parallel ports started disappearing. “Legacy free” PC’s became the norm. Hackers, Makers, and Engineers had no choice but to jump on the bandwagon, which they did with great gusto. Today everything has a USB port. From 8 bit microcontrollers to cell phones to children’s toys. This week’s Hacklet is about some of the best USB projects on!

two partsWe start with [Michael Mogenson] and Two Component USB Temperature Data Logger, which may be the simplest USB device ever made. [Michael] isn’t kidding. This data logger consists of just a Microchip PIC16F1455 microcontroller and a USB connector. Microchip’s datasheet calls for a capacitor to smooth out power, but [Michael] made it work without the extra part. He used M-Stack by Signal 11 to implement the USB stack. Once connected to a PC, the PIC enumerates as a serial port device. It then sends its die temperature of the PIC once per second. It could do more, but that would probably require adding a few more components!

tester1Next up is [davedarko] with USB cable tester. Dave recently spent some time installing USB RFID readers. These devices were only a few meters away from the computer controlling them. Even so, the power and USB data cables had to run through pipes and in some cases under water. It wasn’t fun troubleshooting a device to find that it was a shorted USB cable causing the problem. [Dave’s] solution is a tiny coin cell powered board that tests each of the 4 wires in a standard USB 2.0 cable. The board runs on an ATtiny45 microcontroller. [Dave’s] current iteration has footprints for mini and micro USB connectors, along with the standard USB-A.


tester2[MobileWill] has a USB Tester of his own. This USB tester checks current consumption and rail voltage. It does this by connecting in-line with the device under test. It’s perfect for troubleshooting why your PC’s USB port goes into over-current protection every time you plug in your device. The tester is modular – you can use the base board with your own multimeter, or grab [Will’s] tester backpack and see the results right on the built-in OLED display. USB Tester is [Will’s] entry in the 2015 Hackaday Prize.


tbdFinally, we have [ajlitt] with Tiny Bit Dingus (TBD). TBD is a USB interface to 6 wires. Think of it as a tiny version of the bus pirate. This lilliputian board holds a Freescale KL27Z ARM processor, which has more than enough power to handle things like I2C, SPI, PWM, or just about any other way to send data or wiggle wires. [Ajlitt] started this project as an excuse to learn KiCAD and gain some experience with surface mount solder stencils. The result is an absolutely tiny board that is all but lost in a USB socket. Programming is handled with the mbed library, though you can always use Freescale’s native tools. Flashing code on the TBD is easy with kut, a chrome browser plugin.

If you want to see more USB projects, check out our new USB projects list. Did I miss your project? Don’t be shy, just drop me a message on That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of!

Simple USB Power Meter

The USB interface is being increasingly used as a power supply and charging port for all kinds of devices, besides data transfer. A meter to measure the electrical parameters of devices connected to a USB socket or charger would be handy on any hacker workbench. The folks at [electro-labs] designed this simple USB power meter which does just that.

The device measures voltage and current and displays them, along with the calculated power, on the small 0.5″ OLED display. The circuit is built around an ATmega328. To keep the board size small, and reduce component count, the microcontroller is run off its internal 8MHz clock. A low-resistance shunt provides current sensing which is amplified by the LT6106 a high side current sense amplifier before being fed to the 10 bit analog port of the ATmega. A MCP1525 precision voltage reference provides 2.5V to the Analog reference pin of the microcontroller, resulting in a 2.44mV resolution. Voltage measurement is via a resistive divider that has a range of up to 6V. An Arduino sketch reads voltage and current data on the analog ports and displays measurements on the display. The measured data is averaged to filter out noise.

The OLED display has a SPI interface and requires the u8glib library. The project uses all SMD parts, but is fairly easy to assemble by hand and could be a nice starter project if you want to wet your feet on surface mount assembly techniques. It’s designed using SolaPCB EDA software, and the source files for schematic and board layout are available as a ZIP archive. Download the BoM and Arduino code and you have everything needed to build this nifty device.

Thanks to [Abdulgafur] for sending in this tip. And if you are looking for a more comprehensive solution, check the awesome Friedcircuits USB Tester which we reviewed earlier and is available in the Hackaday Store.

Slimline USB Charger for tiny ham Radios

The recent trend to smaller and smaller handy talkie (HT) transceivers is approaching the limits of the human interface. Sure, engineers could probably continue shrinking the Baofeng and Wouxun HTs further, but pretty soon they’ll just be too small to operate. And it’s getting to the point where the accessories, particularly the battery charging trays, are getting bulkier than the radios. With that in mind, [Mads Hobye] decided to slim down his backpacking loadout by designing a slimline USB charger for his Baofeng HT.

Lacking an external charging jack but sporting a 3.7 volt battery pack with exposed charging terminals on the rear, [Mads] cleverly capitalized on the belt clip to apply spring tension to a laser-cut acrylic plate. A pair of bolts makes contact with the charging terminals on the battery pack, and the attached USB cable allows him to connect to an off-the-shelf 3.7 volt LiPo USB charger, easy to come by in multicopter circles. YMMV – the Baofeng UV-5R dual-band HT sitting on my desk has a 7.4 volt battery pack, so I’d have to make some adjustments. But you have to applaud the simplicity of the build and its packability relative to the OEM charging setup.

This isn’t the first time we’ve seen [Mads] on Hackaday. He and the FabLab RUC crew were recently featured with their open-source robotic arm.