Cramming a Pi Zero into a USB Hub

We kinda feel bad posting all these awesome hacks you can do with a Raspberry Pi Zero when we know most of our audience here probably doesn’t have one due to the backlog of orders… but regardless — here’s another one you can try — if you have one anyway. A Raspberry Pi USB Hub!

In case you didn’t know, Amazon has a series of electronics accessories called Amazon Basics — and they’re actually pretty good quality accessories. One of them is a 7-port, 4A USB hub. Looking at this [gittenlucky] figured he might just have enough room to fit a Pi Zero inside… and as it turns out. He did.

Continue reading “Cramming a Pi Zero into a USB Hub”

Build Your Swarm: Control Cockroaches for Under $30!

Have you ever wanted to control an army of cockroaches? We’ve all seen remote control cockroaches before — and they really are quite a fascinating specimen to work with — but did you know you can control one for about $30 worth of components, with a Arduino Micro?

It’s actually pretty simple. By stimulating a cockroaches antenna with variable frequencies (to mimic neural signals) you can convince the cockroach that they’ve hit a wall and should turn the other way. What results is a remote-controlled roach. How cool is that!

Continue reading “Build Your Swarm: Control Cockroaches for Under $30!”

Vacuum? No, Tonight We Go To War Against the Dust Mite

For those of us lucky enough to own a Roomba, it makes taking care of dust in your house a breeze — but it could be better. Which is why [Marcel] spent his weekend upgrading his Roomba — or should we say, Doomba.

He started out with modest intentions. What’s stopping his Roomba from going a bit faster? He was pretty sure he could crank up the output a little bit. Donning his white lab coat and safety glasses, he set out do upgrade this little bot into something much more formidable.

Continue reading “Vacuum? No, Tonight We Go To War Against the Dust Mite”

Flip Your Desktop Over to Boot Linux

[Andy France] built his computer into a Windows XP box. (Yes, this is from the past.) He needed to run windows most of the time, but it was nice to boot into Linux every now and then. That’s where the problem lay. If he was running Linux on his Windows XP case mod, he’d get made fun of. The only solution was to make a Linux sleeve for his computer. He would slide the sleeve over the case whenever he ran Linux, and hide his shame from wandering eyes. Once his plan was fully formed, he went an extra step and modified the computer so that if the sleeve was on, it would automatically boot Linux, and if it was off it would boot Windows.

The Linux sleeve could only slide on if the computer was flipped upside down. So he needed to detect when it was in this state. To do this he wired a switch into one of the com ports of his computer, and attached it to the top of the case mod. He modified the assembly code in the MBR to read the state of the switch. When the Linux sleeve is on (and therefore the computer is flipped over) it boots Linux. When the sleeve is off, Windows. Neat. It would be cool to put a small computer in a cube and have it boot different operating systems with this trick. Or maybe a computer that boots into guest mode in one orientation, and the full system in another.

Continue reading “Flip Your Desktop Over to Boot Linux”

FTDI Drivers Break Fake Chips, Again

Just over a year ago, FTDI, manufacturers of the most popular USB to serial conversion chip on the market, released an update to their drivers that bricked FTDI clones. Copies of FTDI chips abound in the world of cheap consumer electronics, and if you’ve bought an Arduino for $3 from a random online seller from China, you probably have one of these fake chips somewhere in your personal stash of electronics.

After a year, we have the latest update to FTDI gate. Instead of bricking fake chips, the latest FTDI drivers will inject garbage data into a circuit. Connecting a fake FTDI serial chip to a computer running the latest Windows driver will output “NON GENUINE DEVICE FOUND!”, an undocumented functionality that may break some products.

FTDI gate mk. 1 merely bricked fake and clone chips, rendering them inoperable. Because fakes and clones of these chips are extremely common in the supply chain, and because it’s very difficult to both tell them apart and ensure you’re getting genuine chips, this driver update had the possibility to break any device using one of these chips. Cooler heads eventually prevailed, FTDI backed down from their ‘intentional bricking’ stance, and Microsoft removed the driver responsible with a Windows update. Still, the potential for medical and industrial devices to fail because of a random driver update was very real.

The newest functionality to the FTDI driver released through a Windows update merely injects unwanted but predictable data into the serial stream. Having a device spit out “NON GENUINE DEVICE FOUND!” won’t necessarily break a device, but it is an undocumented feature that could cause some devices to behave oddly. Because no one really knows if they have genuine FTDI chips or not – this undocumented feature could cause problems in everything from industrial equipment to medical devices, and of course in Arduinos whose only purpose is to blink a LED.

Right now, the only option to avoid this undocumented feature is to either use Linux or turn off Windows Update. Since the latter isn’t really a great idea, be prepared constantly roll back the FTDI driver to a known good version.

One Hoss Shay and Our Society of Obsolescence

Legend has it that Henry Ford would send engineers out to junkyards all over the US looking for Fords. They were supposed to study each one they found and make note of any parts that had not failed. But it wasn’t so that he could start making all of those parts stronger. Instead, Ford allegedly used this data to determine where he could cut corners in future production runs so as not to waste money by making any part last longer than any other part.

Most things tend to break down rather than completely giving out. Usually it’s only one or two components that stop working and the rest of it is still serviceable. And this is a good thing. It’s what lets us repair PCBs or scavenge parts off them, drive our cars longer, and help save each other’s lives through organ donor programs. Can you imagine how different life would be if each part of every thing failed at the same time?

Continue reading “One Hoss Shay and Our Society of Obsolescence”

Need a Nano-Ammeter? You Already Have One!

[Dannyelectronics] sometimes needs to measure tiny currents. Really tiny, like leakage currents through a capacitor. He’s built a few setups to make the measurements, but he also knew he’d sometimes want to take readings when he didn’t have his custom gear available. So he decided to see what he could do with an ordinary digital meter.

dmm-nano-ammeterAs you might expect, a common digital meter’s current scales aren’t usually up to measuring nano- or pico-amps. [Danny’s] approach was not to use the ammeter scale. Instead, he measures the voltage developed across the input impedance of the meter (which is usually very high, like one megaohm). If you know the input characteristics of the meter (or can calibrate against a known source), you can convert the voltage to a current.

For example, on a Fluke 115 meter, [Danny] found that he could read up to 60nA with a resolution of 0.01nA. A Viktor 81D could resolve down to 2.5pA–a minuscule current indeed.

We’ve looked at the difficulties involved in reading small currents before. If tiny currents aren’t your thing, maybe you’d like to try charging an iPhone with 3 KA, instead.