A High Precision ADC That You Can Understand!

April 21, 2023 by Jenny List 8 Comments

In a world where an analogue to digital converter is all too often an integrated peripheral buried inside a microcontroller, it’s easy to forget how simple these devices can be when built from first principles. An entry in our Op-Amp Challenge from [NNNI] demonstrates this perfectly, it’s a high resolution multi-slope ADC for instrumentation purposes, constructed using a mixture of op-amps, logic chips, and a Raspberry Pi Pico. Best of all, it’s easy to understand, so there’s little of that analogue mystique to worry about.

This type of ADC measures an analogue value by counting how long it takes to charge a capacitor to that voltage. A simple version that measures charge time has a few drawbacks, so this project goes from single slope to multi slope by measuring both charge and discharge times compared to the voltage. Pay attention to component matching and reference stability, and such a design can offer a very high resolution measurement.

The value in this project lies not only in the design itself, but also in the extremely comprehensive description of its operation, which should teach most readers a thing or two. That curvy-line PCB is rather nice, too. We used single slope ADCs to read analogue joysticks back in the day, but we certainly learned something here. Want to see another? This isn’t the first dual slope ADC we’ve seen.

Gen Tojo’s Teeth: Morse Code Shows Up In The Strangest Places

April 21, 2023 by Al Williams 43 Comments

The Baader-Meinhof effect is the common name for what scientists call frequency illusion. Suppose you are watching Star Trek’s Christopher Pike explain how he makes pasta mama, and you’ve never heard of it before. Immediately after that, you’ll hear about pasta mama repeatedly. You’ll see it on menus. Someone at work will talk about having it at Hugo’s. Here’s the thing. Pasta mama was there all along (and, by the way, delicious). You just started noticing it. We sometimes wonder if that’s the deal with Morse code. Once you know it, it seems to show up everywhere.

One of the strangest places we’ve ever heard of Morse code appearing is the infamous case of Tojo’s teeth. If you don’t remember, General Hideki Tojo was one of the main “bad guys” in the Pacific part of World War II. In particular, he is thought to have approved the attack on Pearl Harbor, which started the American involvement in the war globally. Turns out, Tojo would be inextricably tied to Morse code, but he probably didn’t realize it.

The Honorable Attempt

At the end of the war, the US military had a list of people they wanted to try, and Tojo was near the top of their list of 40 top-level officials. As prime minister of Japan, he had ordered the attack that brought the US into the war. He remained prime minister until 1944, when he resigned, but the US had painted him as the face of the Japanese enemy. Often shown in caricature along with Hitler and Mussolini, Tojo was the face of the Japanese war machine to most Americans.

In Allied propaganda, Tojo was one of the “big three”

When Americans tried to arrest him, though, he shot himself. However, his suicide attempt failed. Reportedly, he apologized to the American medics who resuscitated him for failing to kill himself. Held in Sugamo Prison awaiting a trial, he requested a dentist to make him a new set of dentures so he could speak clearly during the trial.

Continue reading “Gen Tojo’s Teeth: Morse Code Shows Up In The Strangest Places” →

Hackaday Podcast 215: Autonomous Race Car, Espresso Robot, And Vintage Computers

April 21, 2023 by Dan Maloney 5 Comments

It’s podcast time again, and this time around Elliot and Dan took a grand tour through the week’s best and brightest hacks. We checked out an old-school analog cell phone that went digital with style, dug into a washing machine’s API, and figured out how to melt metal in the microwave — the right way. Does coffee taste better when it’s made by a robot? Of course it does! Can you get a chatbot to spill its guts? You can, if you know how to sweet talk it. Let’s play Asteroids on an analog oscilloscope, spoof facial recognition with knitting, and feel the need for speed with an AI-controlled model race car. And was VCF East worth the wait? According to Tom Nardi, that’s a resounding “Yes!”

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download your own personal copy!

Continue reading “Hackaday Podcast 215: Autonomous Race Car, Espresso Robot, And Vintage Computers” →

Building A Motorized Pan Tilt Rig For Filming

April 21, 2023 by Lewin Day 3 Comments

Today, anyone can shoot video because cameras are cheap and readily available. But if you want to do fancy Hollywood-style moving shots, you’ll need somebody to point the thing — or a machine to do it for you. [Giovanni Aggiustatutto] went the latter route with this mechanized pan-tilt build.

The build relies on stepper motors for clean and accurate movement on both axes. Belt drives are used to step down the output of the motors for greater torque. The pan-tilt mechanism itself is built from a combination of 3D printed parts paired with wooden components and a pair of aluminium tubes for rigidity. The whole assembly comes with a standard mount for use with a regular tripod. An Arduino Uno runs the show, using TMC2208 stepper drivers to command the motors. A control pad featuring a joystick and buttons is used for control, with an LCD to provide useful feedback to the user.

Pan-tilt systems are more typically used for security purposes, but we like the application to creative work here.

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This Week In Security: Spandex Tempest, Supply Chain Chain, And NTP

April 21, 2023 by Jonathan Bennett 14 Comments

Microsoft’s Threat Intelligence group has announced a new naming scheme for threat actors. It sounds great, naming groups after weather phenomenon, based on the groups motivations or nation of origin. Then each discreet group is given an additional adjective. That’s where things get interesting.

It seems like the adjectives were chosen at random, giving rise for some suitably impressive names, like Ghost Blizzard, Ruby Sleet, or Granite Typhoon. Some of the other names sound like they should be desserts: Caramel Tsunami, Peach Sandstorm, Aqua Blizzard, or Raspberry Typhoon. But then there the really special names, like Wine Tempest and Zigzag Hail. But the absolute winner is Spandex Tempest. No word yet on whether researchers managed to keep a straight face when approving that name.

Chrome 0-day Double

A pair of Chrome browser releases have been minted in the past week, both to address vulnerabilities that are actively being exploited. Up first was CVE-2022-2033, type confusion in the V8 JS engine. That flaw was reported by Google’s Threat Analysis Group, presumably discovered in the wild, and the fix was pushed as stable on the 14th.

Then, on th 18th, yet another released rolled out to fix CVE-2023-2136, also reported by the TAG, also being exploited in the wild. It seems likely that both of these 0-days were found in the same exploitation campaign. We look forward to hearing the details on this one. Continue reading “This Week In Security: Spandex Tempest, Supply Chain Chain, And NTP” →

Getting The Most From Fading ThinkPads

April 21, 2023 by Bryan Cockfield 40 Comments

The ThinkPad line of laptops has been widely prized not only by businesses but also by those who appreciate a high standard of hardware quality and repairability. But some think the cracks are starting to form in their reputation, as it seems that new ThinkPads are sacrificing quality for aesthetics and cost. As a result a huge modding scene has popped up around models that are a few years old like [Cal] found out when working on this X230.

At first he only made some cosmetic improvements to the laptop like replacing the worn palm rest, but quickly found himself in a rabbit hole with other upgrades like swapping out the keyboard and battery. The new keyboard is a 7-row X220 keyboard, which required modification of the connector and flashing the embedded controller with a hacked image to change the keyboard map without needing to make changes at the OS level. From there, he decided to replace the lackluster screen with a 1920×1080 matte IPS panel using an adapter board from Nitrocaster, and finished off his upgrades with a customized Coreboot BIOS for improved performance and security.

While Coreboot doesn’t remove all of the binary blobs that a bootloader like libreboot does, the latter is not compatible with more modern machines like this X230. Still, you’ll get many benefits from using Coreboot instead of the stock bootloader. For running Linux on a daily driver laptop, we appreciate all of these updates and expect that [Cal] will get plenty of years of use out of his machine. We’ve definitely seen an active modding scene for ThinkPads that were (at the time) seven years old and still going strong, so we’d expect nothing less for this one.

Linux Server, Wakey, Wakey

April 21, 2023 by Al Williams 39 Comments

We all know we should save energy and not leave computers on all the time. It is probably better for the computer, too. But when you operate a home server, it isn’t feasible to just turn it on when you want to use it and then turn it off again. Or is it? [Daniel] decided that was exactly what he wanted to do, and it was quite an adventure to get there.

The trick is to use a Raspberry Pi — they don’t draw nearly the power a big computer does — to stay awake to facilitate the process. The Pi watches for ARP requests for the sleeping machine and replies on its behalf so that other network nodes can find the machine even when it isn’t on.

The server itself detects if it is idle in a cron job. When it finds that there are no SSH or other service connections for a set period of time, it suspends the machine to RAM, putting it in a low-power mode. Waking a sleeping computer up over the network is a solved problem, and [Daniel] investigated several wake-on-lan solutions.

There were several oddities to work out, including a Mac pinging an unused network share, and a router that was making NetBIOS queries. However, [Daniel] found a $30 router that could do port mirroring and that helped a lot with troubleshooting.

This is one of those things where his recipe won’t exactly fit your situation. But the post has a lot of good information and some nice tricks for troubleshooting any kind of network bizarreness.

Wireshark is a great tool for this kind of work, too. Another useful technique is recording network traffic and playing it back.