Small Engine Failure Leads To Impromptu Teardown

September 1, 2022 by Tom Nardi 20 Comments

When the 6.5 HP (212 cc) Harbor Freight Predator engine in his kid’s go-kart gave up the ghost after some particularly hard driving, [HowToLou] figured it would be a good time to poke around inside the low-cost powerplant for our viewing pleasure. As a bonus, he even got it up and running again.

For an engine that has a retail price of just $160 USD, we’ve got to admit, the inside of the Predator doesn’t look too shabby. Admittedly, [HowToLou] determined that the cause of the failure was a blown connecting rod, but he also mentions that somebody had previously removed the engine’s governor, allowing it to rev up far beyond the nominal maximum of 3,600 RPM. No word on who snuck in there and yanked the governor out, but we’re betting it wasn’t the 7-year old driver…

Replacing the connecting rod meant taking most of the engine apart, but for our education, [HowToLou] decided to take it a bit further and remove everything from the engine. After stripping it down to the block, he re-installs each piece while explaining its function. If you’ve ever wanted to see what makes one of these little engines tick, or perhaps you’ve got a Predator 212 cc in need of a repair or rebuild, the presentation is a fantastic resource.

Incidentally, this isn’t the first time we’ve seen the go-kart in question — back in June, we covered the unique electric reverse that [HowToLou] came up with for it.

A multimeter connected to the EEPROM chip with crocodile clips, showing that there's a 0.652V diode drop between GND and one of the IO pins

Dead EPROM Dumped With Help Of Body Diodes

August 26, 2022 by Arya Voronova 9 Comments

[Jason P], evidently an enjoyer of old reliable laser printing tech, spilled a drink (nitter) onto his Panasonic KX-P5400 SideWriter. After cleanup, everything worked fine — except that the PSU’s 5 V became 6.5 V during the accident, and the EPROM with LocalTalk interface firmware died, connection between VCC and GND seemingly interrupted inside the chip. Understandably, [Jason] went on Twitter, admitted the error of his ways, and sheepishly asked around for EPROM dumps.

Instead, [Manawyrm] wondered — would the chip have anti-ESD body diodes from GND to IO pins, by any chance? A diode mode multimeter check confirmed, yes! It was time for an outlandish attempt to recover the firmware. [Manawyrm] proposed that [Jason] connect all output pins but one to 5 V, powering the EPROM through the internal VCC-connected body diodes – reading the contents one bit at a time and then, combining eight dumps into a single image.

After preparing a TL866 setup, one hour of work and some PHP scripting later, the operation was a success. Apparently, in certain kinds of cases, dead ROM chips might still tell their tales! It’s not quite clear what happened here. The bond wires looked fine, so who knows where the connection got interrupted – but we can’t deny the success of the recovery operation! Need a primer on dumping EPROMs that are not dead? Here you go.

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Frequency Counter Restoration Impeded By Kittens

August 24, 2022 by Al Williams 12 Comments

We think of digital displays as something you see on relatively modern gear. But some old gear had things like nixies or numitrons to get cool-looking retro digital displays. The HP 521A frequency counter, though, uses four columns of ten discrete neon bulbs to make a decidedly low-tech but effective digital display. [Usagi Electric] has been restoring one of these for some time, but there was a gap between the second and third videos as his workshop became a kitten nursery. You can see the last video below.

In previous videos, he had most of the device working, but there were still some odd behavior. This video shows the final steps to success. One thing that was interesting is that since each of the four columns are identical, it was possible to compare readings from one decade to another.

However, in the end, it turned out that the neon bulbs were highly corroded, and replacing all the neon bulbs made things work better. However, the self-check that should read the 60 Hz line frequency was reading 72 Hz, so it needed a realignment. But that was relatively easy with a pot accessible from the back panel. If you want to see more details about the repair, be sure to check out the earlier videos.

We love this old gear and how clever designers did so much with what we consider so little. We hate to encourage your potential addiction, but we’ve given advice on how to acquire old gear before. If you want to see what was possible before WS2812 panels, you could build this neon bulb contraption.

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Drastic Plastic: Enclosure Rebuild Uses Donor Material

August 21, 2022 by Kristina Panos 10 Comments

Although 3D printers are great, people tend to use them as a universal hammer wherein almost everything becomes a nail that’s just begging to be struck. So as hacker appetites become finicky with the same old fare, it’s refreshing to see an enclosure restoration done in such an old-school fashion. To wit: [Doidão Santos]’ classic repair of the crumbling side fairings on a vintage amplifier.

Yes, instead of designing replacement pieces, printing them, and hiding the layered evidence with paint or an acetone blur, [Doidão] called upon a broken sound system whose chassis bore a relief in the corners similar to that of the amplifier.

After cutting out two matched pieces of donated plastic, [Doidão] taped them together and welded ’em with a soldering iron outfitted with a curved-but-flattened spade tip that looks ideal for this purpose. Although the donor enclosure provided much-needed relief, one corner was lacking in this aesthetic, so [Doidão] cast a little bit of molten plastic using the relief as a mold.

Once the pieces were tacked together, [Doidão] filed them down, sanded them, polished them to a nice shine, and installed them on the amplifier. They look great, and no one will be the wiser. But if we were in [Doidão]’s shoes, we’d tell everyone what we’d done. Be sure to check it out after the break.

Ready for more fantastic plastic resto-hacks? Let us introduce you to [drygol].

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Did You See A John Deere Tractor Cracked At DEF CON?

August 17, 2022 by Jenny List 6 Comments

The Internet, or at least our corner of it, has been abuzz over the last few days with the news of a DEF CON talk by [Sick.Codes] in which he demonstrated the jailbreaking of the console computer from a John Deere tractor. Sadly we are left to wait the lengthy time until the talk is made public, and for now the most substantive information we have comes from a couple of Tweets. The first comes from [Sick.Codes] himself and shows a game of DOOM with a suitably agricultural theme, while the second is by [Kyle Wiens] and reveals the tractor underpinnings relying on outdated and un-patched operating systems.

You might ask why this is important and more than just another “Will it run DOOM” moment. The answer will probably be clear to long-term readers, and is that Deere have become the poster child for improper use of DRM to lock owners into their servicing and deny farmers the right to repair. Thus any breaches in their armor are of great interest, because they have the potential to free farmers world-wide from this unjust situation. As we’ve reported before the efforts to circumvent this have relied on cracked versions of the programming software, so this potential jailbreak of the tractor itself could represent a new avenue.

As far as we’re aware, this has so far taken place on the console modules in the lab and not in the field on a real tractor. So we’re unsure as to whether the door has been opened into the tractor’s brain, or merely into its interface. But the knowledge of which outdated software can be found on the devices will we hope lead further to what known vulnerabilities may be present, and in turn to greater insights into the machinery.

Were you in the audience at DEF CON for this talk? We’d be curious to know more. Meanwhile the Tweet is embedded below the break, for a little bit of agricultural DOOM action.

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Hackaday Prize 2022: Saving The World, One Brew At A Time

August 5, 2022 by Elliot Williams 10 Comments

OK, so maybe [satanistik] is overreaching with his project title “Save the Coffee, Save the World” but keeping an otherwise working coffee machine out of the landfill by hacking around its broken display is nonetheless a worthy pursuit. The juice must flow!

The busted display used a SSD1303 controller OLED module, for which the SSD1305Z is an almost-compatible module. Almost. The one glitch is that the screen is filled in the opposite direction by default. Digging through the manuals, there is a screen-direction bit to set, and tracing out the communication with a logic analyzer, it’s set the wrong way with every screen refresh. If only he could flip that one bit while it’s in transit. Time to man-in-the-middle!

While we certainly would have put a microcontroller in the game, [satanistik] goes old-school. A two-IC logic solution can do exactly the same thing, trading wires for code. The final iteration of the converter board is correspondingly spartan, but it does its one job.

So if you’ve got a Nivona coffee machine with a bum display, or perhaps an Agilent U1273A multimeter, or any other piece of equipment that needs a hard-to-find SSD1303 controller, now you have a ready-made solution. But if not, and you find yourself looking for a display that you can’t find, let this serve as an example to you – with a little (fun) effort, you can hack it back.

Tablet ina 3D printed stand, showing timetables on its screen

Revive Your Old E-Ink Tablet For Timetable Helper Duty

August 2, 2022 by Arya Voronova 17 Comments

In our drawers, there’s gonna be quite a few old devices that we’ve forgotten about, and perhaps we ought to make them work for us instead. [Jonatron] found a Nook Simple Touch in his drawer – with its E-ink screen, wireless connectivity and a workable Android version, this e-reader from 2011 has the guts for always-on display duty. Sadly, the soft touch covering on the back disintegrated into a sticky mess, as soft touch does, the LiIon battery has gone flat, and the software support’s lackluster. Both of these are likely to happen for a lot of tablets, which is why we’re happy [Jonatron] has shared his story about this e-reader’s revival.

The soft touch layer on the back didn’t go away with help of alcohol, but by sheer luck, an acetone bottle was nearby, and an acetone scrub helped get rid of the unpleasant stickiness. The tablet’s charging circuitry turned out to be unsophisticated – the tablet wouldn’t boot from MicroUSB input, and [Jonathan] wired up 5 volts from a USB cable straight into the battery input. Mind you, this might not be advised, as Lithium-Ion battery range is from 3 volts to 4.2 volts and a regulator would be called for, but [Jonatron] says it’s been working just fine.

Usually, you could just put a webserver on your local network and serve a page with useful information, adding code to refresh the page periodically – but the Nook’s browser didn’t support automatic refreshes. Not to be stopped, [Jonatron] wrote an app for the Nook’s Android install instead; rooting was required but went seamlessly. The Android install is old, and Android Studio for it is no longer downloadable, so he used an older development toolkit somehow still available online. There’s still a small Python-written webserver running on a spare Pi, conditioning the data for the app to fetch. Following best hacker traditions, both the app and the server are open-sourced! With help of a 3D printed stand, this tablet now displays train departure schedules – perfect application for an old e-reader like this.

Got a Nook Simple Touch in a drawer? Now you know you can easily convert it into a hackable E-ink display! We’ve seen numerous tablet restorations before, replacing charger ICs and eMMC drives, turning them into videophones to chat with our relatives and smart home controllers, and there’s even repair databases to help you in your revival efforts. We’ve been getting quite a few projects like these in our last Hackaday Prize installment, Hack It Back, and we hope to see more such rebuilds for our Wildcard round!