Hackaday Podcast 086: News Overflow, Formula 1/3 Racer, Standing Up For Rubber Duckies, And Useless Machine Takes A Turn

Hackaday editors Elliot Williams and Mike Szczys peruse the world of hacks. There was so much news this week that we lead off the show with a rundown to catch you up. Yet there is still no shortage of hardware hacks, with prosthetic legs for your rubber ducky, a RC cart that channels the spirit of Formula 1, and a project that brings 80’s video conferencing hardware to Zoom. There’s phosphine gas on Venus and unlimited hacking projects inside your guitar. The week wouldn’t be complete without the joy of riffing on the most useless machine concept.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 086: News Overflow, Formula 1/3 Racer, Standing Up For Rubber Duckies, And Useless Machine Takes A Turn”

This Week In Security: UTorrent Vulnerable, Crowd-Sourcing Your Fail2Ban, And Cryptographers At Casinos

The uTorrent client was recently updated to fix a null pointer dereference (CVE-2020-8437), discovered by [whtaguy]. Triggering the dereference simply crashes the client — so far an actual RCE hasn’t been found. Given the nature of the null pointer dereference, it’s possible this bug is limited to denial of service. That’s extremely good, because the flaw is extremely easy to target.

BitTorrent is a clever protocol. It’s still used to distribute large files, like Linux ISOs. The concept is simple: Split a large file into small chunks. Send the chunks to a client one at a time. As each chunk is received, the client sends a copy of that chunk to the next client. As a result of this peer-to-peer (p2p) arrangement, the bandwidth available to the server is greatly multiplied. As with all other p2p arrangements, the sticking point is how to make those connections between peers, particularly when most of the world’s desktops are behind NAT routers. In practice, for two peers to share data, at least one of them has to have a port opened or forwarded to the client. This is often accomplished through Universal Plug-n-Play (UPnP) or the NAT Port Mapping Protocol (NAT-PMP). The idea of both protocols are the same; a client on an internal device can request a temporary port forward without manual intervention. Whether it’s a good idea to allow automatic port forwards is another issue for another day. Continue reading “This Week In Security: UTorrent Vulnerable, Crowd-Sourcing Your Fail2Ban, And Cryptographers At Casinos”

In Praise Of The DT830, The Phenomenal Instrument You Probably Don’t Recognise For What It Is

If we had to make a guess at the single piece of electronic bench equipment owned by the highest proportion of Hackaday readers, it would not be a budget oscilloscope from Rigol, nor would it be a popular portable soldering iron like the TS100. Instead we’re guessing that it’s a multimeter, and not even the most accomplished one.

The DT830 is a genericised Chinese-manufactured 3.5 digit digital multimeter that can be had for an astonishingly low price. Less than a decent hamburger gets you an instantly recognisable plastic case with a chunky rotary range selector switch, and maybe a socket for some kind of transistor or component tester. Make sure that there is a 9 volt battery installed, plug in the pair of test leads, and you’re in business for almost any day-to-day electrical or electronic measurement. They’ve been available in one form or another for decades and have been the subject of innumerable give-aways and loss-leader offers, so it’s a reasonsble guess that you’ll have one somewhere. I have three as far as I know, they make great on-the-go instruments and have proved themselves surprisingly reliable for what they are. Continue reading “In Praise Of The DT830, The Phenomenal Instrument You Probably Don’t Recognise For What It Is”

Inputs Of Interest: BIGtrack Mouse Might Make You Squeal

You know me, I like to get my feet involved when I use my computer, which happens pretty much all day every day at this point. My cache of pedal inputs keeps growing like mushrooms in the darkness under my desk: every upper case letter in this post and dozens more have been capitalized with a shift pedal!

Naturally, I’ve thought about what it might be like to mouse with my toes. The more time I can spend with both hands on the keyboard, the better. I started sniffing around for foot-sized trackball candidates, thinking maybe I could just build one with regular mouse guts. Then I found a 15-year-old Golden Tee home edition console at a thrift store. It has a large ball and four buttons, so it seemed ripe for turning into a mouse as-is, or just stealing the ball to build my own. So far, that hasn’t happened, though I did solder a bunch of wires for testing out the controls. Continue reading “Inputs Of Interest: BIGtrack Mouse Might Make You Squeal”

Axe Hacks: New Sounds For Your Electric Guitar Beginning From What Makes Them Tick

Creating music is a perfect hobby for anyone into hacking, and the amount of musical hacks and self-made instruments we come across here makes that supremely evident. It’s just a great match: you can either go full-on into engineering mode as music is in the end “just” applied physics, or simply ignore all of the theory and take an artistic approach by simply doing whatever feels right. The sweet spot is of course somewhere in between — a solid grasp of some music theory fundamentals won’t hurt, but too much overthinking eventually will.

The obvious choice to combine a favorite pastime like electronics or programming with creating music would be in the realm of electronic music, and as compelling as building synthesizers sounds, I’ll be going for the next best thing instead: the electric guitar. Despite its general popularity, the enormous potential that lies within the electric guitar is rarely fully utilized. Everyone seems to just focus on amp settings and effect pedals when looking for that special or unique sound, while the guitar itself is seen as this immutable object bestowed on us by the universe with all its predestined, magical characteristics. Toggle a pickup switch, and if we’re feeling extra perky, give that tone pot a little spin, that’s all there is to it.

The thing is, the guitar’s electrical setup — or wiring — in its stock form simply is as boring and generic as it can get. Sure, it’s a safe choice that does the job well enough, but there’s this entirely different world of tonal variety and individual controllability locked inside of it, and all it really takes is a screwdriver and soldering iron to release it. Plus, this might serve as an interesting application area to dive into simple analog electronics, so even if guitars aren’t your thing yet, maybe this will tickle your creativity bone. And if bass is more your thing, well, let me be ignorant and declare that a bass is just a longer guitar with thicker, lower-tuned strings, meaning everything that follows pretty much applies to bass as well, even if I talk about guitars.

However, in order to modify something, it helps to understand how it functions. So today, we’ll only focus on the basics of an electric guitar, i.e. what’s inside them and what defines and affects their tone. But don’t worry, once we have the fundamentals covered, we’ll be all settled to get to the juicy bits next time.

Continue reading “Axe Hacks: New Sounds For Your Electric Guitar Beginning From What Makes Them Tick”

Linux Fu: Simple SSH File Sharing

If you have more than one Linux computer, you probably use ssh all the time. It is a great tool, but I’ve always found one thing about it strange. Despite having file transfer capabilities in the form of scp and sftp, there is no way to move a file back or forth between the local and remote hosts without starting a new program on the local machine or logging in from the remote machine back to the local machine.

That last bit is a real problem since you often access a server from behind a firewall or a NAT router with an ephemeral IP address, so it can’t reconnect to you anyway. It would be nice to hit the escape character, select a local or remote file, and teleport it across the  interface, all from inside a single ssh session.

I didn’t quite get to that goal, but I did get pretty close. I’ll show you a script that can automatically mount a remote directory on the local machine. You’ll need sshfs on the local machine, but no changes on the remote machine where you may not be able to install software. With a little more work, and if your client has an ssh server running, you can mount a local directory on the remote machine, too. You won’t need to worry about your IP address or port blocking. If you can log into the remote machine, you are good.

Combined, this got me me very close to my goal. I can be working in a shell on either side and have access to read or write files on the other side. I just have to set it up carefully. Continue reading “Linux Fu: Simple SSH File Sharing”

Into The Plasmaverse Hack Chat

Join us on Wednesday, September 23 at noon Pacific for the Into the Plasmaverse Hack Chat with Jay Bowles!

Most kids catch on to the fact that matter can exist in three states — solid, liquid, and gas — pretty early in life, usually after playing in the snow a few times. The ice and snowflakes, the wet socks, and the fog of water vapor in breath condensing back into water droplets all provide a quick and lasting lesson in not only the states of matter but the transitions between them. So it usually comes as some surprise later when they learn of another and perhaps more interesting state: plasma.

For the young scientist, plasma is not quite so easy to come by as the other phases of matter, coming about as it does from things they’re usually not allowed to muck with. High voltage discharges, strong electromagnetic fields, or simply a lot of heat can strip away electrons from a gas and make the ionized soup that we call plasma. But once they catch the bug, few things can compare to the dancing, frenetic energy of a good plasma discharge.

Jay Bowles picked up the plasma habit quite a while back and built his YouTube channel around it. Tesla coils, Van de Graaff generators, coils and capacitors of all types — whatever it takes to make a spark, Jay has probably made and used it to make the fourth state of matter. He’ll join us on the Hack Chat to talk about all the fun things to do with plasma, high-voltage discharge, and whatever else sparks his interest.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, September 23 at 12:00 PM Pacific time. If time zones baffle you as much as us, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Continue reading “Into The Plasmaverse Hack Chat”