Building An Open Source ThinkPad Battery

September 2, 2020 by 13 Comments

If you own a laptop that’s got a few years on the clock, you’ve probably contemplated getting a replacement battery for it. Which means you also know how much legitimate OEM packs cost compared to the shady eBay clones. You can often get two or three of the knock-offs for the same price as a single real battery, but they never last as long as the originals. If they even work properly at all.

Which is why [Alexander Parent] decided to take the road less traveled and scratch built a custom battery for his ThinkPad T420. By reverse engineering how the battery pack communicated with the computer, he reasoned he would be able to come up with an open source firmware that worked at least as well as what the the third party ones are running. Which from the sounds of it, wasn’t a very high bar. From a more practical standpoint, it also meant he’d be able to create a higher capacity battery pack than what was commercially available should he chose to.

A logic analyzer wired in between one of the third party batteries and a spare T420 motherboard allowed [Alexander] to capture all the SMBus chatter between the two. From there he wrote some Arduino code that would mimic a battery as a proof of concept. He was slowed down a bit by an undocumented CRC check, but in the end he was able to come up with a fairly mature firmware that even allows you to provide a custom vendor name and model number for your pack.

The code was shifted over to an ATtiny85, with a voltage divider wired up to one of the pins so it can read the pack voltage. [Alexander] says his firmware still doesn’t do a great job of reporting the actual battery capacity remaining, but it’s close enough for his purposes. He came up with a simple PCB design to hold the MCU and support components, which eventually he plans on putting inside of a 3D printed case that actually plugs into the back of his T420.

This project is obviously still in a relatively early stage, but we’re very interested to see [Alexander] take it all the way. The ThinkPad has long been the hacker’s favorite laptop, and we can think of no machine more worthy of a fully open hardware and software battery pack.

Pause Your Tunes When It Is Time To Listen Up!

September 2, 2020 by 9 Comments

“Sorry. I had music playing. Would you say that again?” If we had a money-unit every time someone tried talking to us while we were wearing headphones, we could afford a super-nice pair. For an Embedded C class, [extremerockets] built Listen Up!, a cutoff switch that pauses your music when someone wants your attention.

The idea was born while sheltering in place with his daughter, who likes loud music, but he does not want to holler to get her attention. Rather than deny her some auditory privacy, Listen Up! samples the ambient noise level, listens for a sustained rise in amplitude, like speech, and sends a pause signal to the phone. Someday, there may be an option to route the microphone’s audio into the headphones, but for now there is a text-to-speech module for verbalizing character strings. It might be a bit jarring to hear a call to dinner in the middle of a guitar riff, but we don’t like missing dinner either, so we’re with [extremerockets] on this one.

We don’t really need lots of money to get fun headphones, and we are not afraid of making our own.

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The B-Sides: Curious Uses Of Off-the-Shelf Parts

September 2, 2020 by 44 Comments

I admit: a few years of prototyping without easy machine shop access really whets my tastebuds for turning metal chips. But all that time spent away from proper machine tools has also pushed me to re-imagine part catalogs, something I see almost every day. Without any precision metalworking tools handy, stock mechanical parts have become my supplement for complexity. And so a former dogma to machine-everything-thyself has been transformed into a hunt for that already-made-part-that-does-it-for-you.

But with part catalogs featuring tens of thousands of purpose-built parts, I started reimagining some of them for other misdeeds. And after a few years spent reinventing use cases for some of these parts, I’m about ready to tell you how to misuse them properly. So today I’d like to show you some of my favorite mechanical part B-sides, so to speak. These are ordinary parts in unorthodox places–something you surely won’t find in the datasheet! Now let’s have a look. Continue reading “The B-Sides: Curious Uses Of Off-the-Shelf Parts” →

Hacker Driven To Build R/C Forza Controller

September 2, 2020 by 6 Comments

Generic video game console controllers have certainly gotten better and more ergonomic since the hard corners of the Atari joystick. As beautiful and engrossing as games have become, the controller is still the least engaging aspect. Why race your sweet fleet of whips with an ordinary controller when you could pretend they’re all R/C cars?

[Dave] found an affordable 4-channel R/C controller in the Bezos Barn and did just that. It took some modifications to make it work, like making a daughter board to turn the thumb grip input from a toggle button to a momentary and figuring out what to do with the three-way slider switch, but it looks like a blast to use.

The controller comes in a 6-channel version with two pots on the top. Both versions have the same enclosure and PCB, so [Dave] already had the placement molded out for him when he decided to install a pair of momentary buttons up there. These change roles based on the three-way slider position, which switches between race mode, menu mode, and extras mode.

We love the way [Dave] turned the original receiver into a USB dongle that emulates an Xbox 360 controller — he made a DIY Arduino Pro Micro with a male USB-A, stripped down the receiver board, and wired them together. There’s an entire separate blog post about that, and everything else you’d need to make your own R/C controller is on GitHub. Check out the demo and overview of the controls after the break.

[Dave] is no stranger to making game controllers — we featured his DJ Hero controller modified to play Spin Rhythm XD a few months ago.

Continue reading “Hacker Driven To Build R/C Forza Controller” →

An Up-Close Look At The First Martian Helicopter

September 2, 2020 by 49 Comments

The news was recently abuzz with stories of how the Mars 2020 mission, which launched from Cape Canaveral at the end of July, had done something that no other spacecraft had done before: it had successfully charged the batteries aboard a tiny helicopter that is hitching a ride in the belly of the Mars 2020 rover, Perseverance.

Although the helicopter, aptly named Ingenuity, is only a technology demonstrator, and flight operations will occupy but a small fraction of the time Mars 2020 is devoting to its science missions, it has still understandably captured the popular imagination. This will be humanity’s first attempt at controlled, powered flight on another planet, after all, and that alone is enough to spur intense interest in what amounts to a side-project for NASA. So here’s a closer look at Ingenuity, and what it takes to build a helicopter that will explore another world.

Continue reading “An Up-Close Look At The First Martian Helicopter” →

Staged Train Wrecks: An Idea That Ran Out Of Steam

September 2, 2020 by 35 Comments

Before there were demolition derbies, there were train totalings. That’s right, somebody had the idea to take a couple of worn-out train engines that were ready for the scrap heap, point them at each other, and drive them full steam ahead. And their boss said capital idea, let’s do it. This was the late 1890s.

Maybe it wasn’t the safest way to spend an evening, but a staged train wreck was surely an awesome spectacle to behold. Imagine being one of the brave engineers who had no choice but to get the train going as fast as possible and then jump out at the last second. A demolition derby seems like child’s play by comparison.

The largest and most widely-publicized wreck was put on by a man named William George Crush who was trying to find new ways to promote the Missouri-Kansas-Texas passenger railway. Once he got the okay, Crush found a large field surrounded by three hills that made for excellent viewing. He stood up a temporary town complete with a circus tent restaurant, a wooden jail cell, and 200 rent-a-constables.

On September 15th, 1896, forty thousand people gathered to watch two trains collide along a section of purpose-built track. They hit each other going 50 mph (80 km/h) and both engines exploded, sending hot iron projectiles every which way. Several people were injured, a few died, and a hired photographer lost an eye to shrapnel. Train totalings nevertheless continued until the Great Depression of the 1930s, when the practice was discarded as wasteful.

Thanks for the tip, [Martin]!

WiiBoy Color Is Exactly What It Sounds Like

September 2, 2020 by 16 Comments

Anyone can go out and buy a handheld console, and if you want to be the cool kid on the school bus, you can always ask your parents to take you out to get one. But if you want real street cred that lasts through your adult years, you’ve gotta put something together yourself. [GingerOfMods] has done just that with the Wiiboy Color. 

Yes, it’s another home-console-turned-portable, and it’s perfomed with exquisite execution. The Wii motherboard is cut and sliced to the absolute bare minimum, as the aim was to build the entire system to the rough form factor of the original Game Boy Color. Custom PCBs were then used to link the chopped ‘board to peripherals, such as the USB drive used to load games and the circuitry from a Gamecube controller. The screen is a beautiful looking 3.5″ IPS LCD, running at 480p and originally intended for use as an automotive backup camera. Battery life is around 2-3 hours, with a USB-C port included for easy charging. More details are included on the forum build log.

It’s a tidy build, and the 3D printed case, Switch joysticks and DS Lite buttons give it a near-production quality finish. [GingerOfMods] intends to build more for commissions, though expect a hefty price tag given the labor and custom work involved. We’ve seen other portable Wiis before too, like this tightly-packed Kapton-heavy build. Video after the break.

Continue reading “WiiBoy Color Is Exactly What It Sounds Like” →