Best Of Both Worlds: The MacPad

Despite a growing demand for laptop-tablet hybrid computers from producers like Lenovo, HP, and Microsoft, Apple has been stubbornly withdrawn this arena despite having arguably the best hardware and user experiences within the separate domains of laptop and tablet. Charitably one could speculate that this is because Apple’s design philosophy mandates keeping the user experiences of each separate, although a more cynical take might be that they can sell more products if they don’t put all the features their users want into a single device. Either way, for now it seems that if you want a touchscreen MacBook you’ll have to build one yourself like the MacPad from [Federico].

This project started as simply providing a high-quality keyboard and mouse for an Apple Vision Pro, whose internal augmented reality keyboard is really only up to the task of occasionally inputting a password or short string. For more regular computing, [Federico] grabbed a headless MacBook which had its screen removed. This worked well enough that it triggered another line of thought that if it worked for the Vision Pro it might just work for an iPad Pro as well. Using Apple tools like Sidecar makes this almost trivially easy from a software perspective, although setting up the iPad as the only screen, rather than an auxiliary screen, on the MacBook did take a little more customization than normal.

The build goes beyond the software side of setting this up, though. It also includes a custom magnetic mount so that the iPad can be removed at will from the MacBook, freeing both the iPad for times when a tablet is the better tool and the MacBook for when it needs to pull keyboard duty for the Vision Pro. Perhaps the only downsides are that this only works seamlessly when both devices are connected to the same wireless network and that setting up a headless MacBook without a built-in screen takes a bit of extra effort. But with everything online and working it’s nearly the perfect Apple 2-in-1 that users keep asking for. If you’re concerned about the cost of paying for an iPad Pro and a Macbook just to get a touchscreen, though, take a look at this device which adds a touchscreen for only about a dollar.

Thanks to [Stuart] for the tip!

Harvard Claims Breakthrough In Anode Behavior Of Solid State Lithium Batteries

One of the biggest issues facing the solid-state lithium-based batteries we all depend upon is of the performance of the anode; the transport of lithium ions and minimization of dendrite formation are critical problems and are responsible for charge/discharge rates and cell longevity. A team of researchers at Harvard have demonstrated a method for using a so-called constriction-susceptible structure on a silicon anode material in order to promote direct metal lithium deposition, as opposed to the predominant alloying reaction. After the initial silicon-lithium alloy layer is formed, subsequent layers are pure lithium. Micrometre-scale silicon particles at the anode constrain the lithiation process (i.e. during charging) where free lithium ions are pushed by the charge current towards the anode area. Because the silicon particles are so small, there is limited surface area for alloying to occur, so direct metal plating of lithium is preferred, but crucially it happens in a very uniform manner and thus does not tend to promote the formation of damaging metal dendrites.

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FLOSS Weekly Episode 773: NodeBB — Don’t Do The Math

This week, Jonathan Bennett and Jeff Massie talk with Julian Lam about NodeBB! It’s modern forum software that actually has some neat tricks up its proverbial sleeves. From forking of forum threads when conversations differ, to new integration with ActivityPub and Mastodon. It’s forums like you’ve never quite seen them.

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The $16 PCB Robot

It is a fun project to build a simple robot but, often, the hardest part these days is creating the mechanical base. [Concrete Dog] has a new open source design for stoRPer that uses a PC board as the base. The board has a Raspberry Pi Pico and motor drivers. The modular design allows you to add to it easily and use custom wheels. The video below shows some treaded wheels and some mechanum wheels with gears.

There are mounting holes for sensors and also a way to put another deck above to hold other circuits, power, or whatever you like. There’s lots you could do with this as a starting point.

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How Powerful Should An Electric Bike Be? The UK Is Asking

As electric drives sweep their way to dominance in the automotive world, there’s another transport sector in which their is also continuing apace. Electric-assisted bicycles preserve the feeling of riding a bike as you always have, along with an electric motor to effortlessly power the rider over hill and dale. European electric two-wheelers are limited to a legal top speed of about 15 miles per hour and a 250 watt motor, but in a post-Brexit dash for independence the British government are asking whether that power should be increased to 500 watts.

The Westminster politicians think such a move will make electric bikes more attractive to consumers, and along with a move to motorcycle-style throttles rather than pedal-to-go throttles they want it to accelerate the take-up of greener transport in a country with plenty of hills. Meanwhile cycling groups and safety groups are concerned, the former whether the move is needed at all, and the latter over the fire risk from more powerful battery packs.

The Hackaday electric bike stable gives us a bit of experience on the matter, and our take is that with a 15 mile-per-hour limit there’s little point in upping the motor power. There’s a 350 watt European limit for three-wheelers though, which we could see would really benefit from a raise if applied to cargo bikes. We can however see that a readily-available supply of cheap 500 W motors would be worth having.

The 1970s Computer: A Slice Of Computing

What do the HP-1000 and the DEC VAX 11/730 have in common with the video games Tempest and Battlezone? More than you might think. All of those machines, along with many others from that time period, used AM2900-family bit slice CPUs.

The bit slice CPU was a very successful product that could only have existed in the 1970s. Today, if you need a computer system, there are many CPUs and even entire systems on a chip to choose from. You can also get many small board-level systems that would probably do anything you want. In the 1960s, you had no choices at all. You built circuit boards with gates on the using transistors, tubes, relays, or — maybe — small-scale IC gates. Then you wired the boards up.

It didn’t take a genius to realize that it would be great to offer people a CPU chip like you can get today. The problem is the semiconductor technology of the day wouldn’t allow it — at least, not with any significant amount of resources. For example, the Motorola MC14500B from 1977 was a one-bit microprocessor, and while that had its uses, it wasn’t for everyone or everything.

The Answer

The answer was to produce as much of a CPU as possible in a chip and make provisions to use multiple chips together to build the CPU. That’s exactly what AMD did with the AM2900 family. If you think about it, what is a CPU? Sure, there are variations, but at the core, there’s a place to store instructions, a place to store data, some way to pick instructions, and a way to operate on data (like an ALU — arithmetic logic unit). Instructions move data from one place to another and set the state of things like I/O devices, ALU operations, and the like.

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Thumbs Up To This Pico MIDI Kalimba

The kalimba, or thumb piano, is an easy way to make some music even if you have next to no idea what you’re doing. The only real downside is that they are limited to the twinkly sounds of metal tines being plucked by thumbs.

[Jeremy Cook] broke the sonic possibilities wide open by converting a couple of kalimbas into capacitive-touch MIDI instruments using the Raspberry Pi Pico. He started with a small one that is curiously made of solid wood. Usually these instruments are at least partially hollow to allow air to resonate inside the body.

After soldering up all the 1 MΩ resistors necessary to utilize the capacitive touch capabilities of the Pico, [Jeremy] found it a bit difficult to play individual notes on such a small instrument, so he made version two out of a much larger specimen.

This time, [Jeremy] cooked up a custom PCB which he is calling the Pico Touch 2, which adds the necessary resistors at the SMD level for capacitive touch sensing and in turn cleans up the wiring a bit. Be sure to check it out in action after the break.

Okay, so you don’t have an iota of musical talent. You could always build a kalimba that plays itself.

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