A Call For Better Shower Temperature Controls

February 18, 2023 by 144 Comments

A good shower is a beautiful, rejuvenating experience. Contrarily, a shower that’s either too hot or too cold becomes a harrowing trial of endurance. [Ben Holmen] has been musing on the way we control temperature in our showers, and he has come to the conclusion that it’s not good enough. He’s done the math, quantified the problem, and is calling for better solutions for all.

[Ben]’s plot of shower temperature vs. mixer tap angle.
[Ben]’s complaint rests with the mixer taps that have become the norm in modern shower installations. These taps have a 180-degree range of motion. On one end, you get maximum cold water output, on the other, maximum hot water output. This is fine for a kitchen sink where we often want one extreme or the other, and exact temperature isn’t important. However, for a shower, it’s terrible.

By [Ben]’s measurements, just a 10-degree range on his own shower tap corresponds to comfortable, usable temperatures. That’s means just 5.6% of the control range is devoted to temperatures the user is likely to select. His argument goes that this is the opposite of how it should work, and that most of the tap’s range should be dedicated to comfortable temperatures.

Ideal water temperature curve, compared to standard tap.

This would allow much finer control of shower temperature in the actual useful range. It would allow us to make tweaks to our shower temperature without having to ever-so-delicately nudge the mixer tap. Extreme hot and extreme cold temperatures should still be available, but left at the utter extremes.

Sadly, [Ben] doesn’t work for Big Tap, so he can’t directly influence the product sold to the public. Instead, he’s calling for manufacturers to develop shower valves that prioritize the temperatures that humans desire most. Unfortunately, it’s not immediately clear how the mechanics of such a valve would work without adding considerable cost and complexity when compared to the traditional model.

What do you think? Are things fine the way they are, or does [Ben] have a point? Perhaps you’re a two-tap evangelist! In any case, we’d love to hear your comments below. Meanwhile, if you’re more worried about the water bill than the temperature, we can help you there as well!

Anatomy Of A Fake CO2 Sensor

February 18, 2023 by 44 Comments

The pandemic brought with it a need to maintain adequate ventilation in enclosed spaces, and thus, there’s been considerable interest in inexpensive C02 monitors. Unfortunately, there are unscrupulous actors out there that have seen this as a chance to make a quick profit.

Recently [bigclivedotcom] got one such low-cost CO2 sensor on his bench for a teardown, and confirms that it’s a fake. But in doing so he reveals a fascinating story of design decisions good and bad, from something which could almost have been a useful product.

Behind the slick color display is a PCB with an unidentified microcontroller, power supply circuitry, a DHT11 environmental sensor, and a further small module which purports to be the CO2 sensor. He quickly demonstrates with a SodaStream that it doesn’t respond to CO2 at all, and through further tests is able to identify it as an alcohol sensor.

Beyond the alcohol sensor he analyses the PSU circuitry. It has a place for a battery protection chip but it’s not fitted, and an error in the regulator circuitry leads to a slow drain of the unprotected cell. Most oddly there’s an entire 5 volt switching regulator circuit that’s fitted but unused, being in place to support a missing infra-red module. Finally the screen is an application-specific LCD part.

It’s clear some effort went in to the design of this unit, and we can’t help wondering whether it could have started life as a design for a higher-spec genuine unit. But as [Clive] says, it’s a party detector, and of little more use than as a project case and battery.

Need more dubious instrumentation? How about a magnetic field tester?

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Hack Lets Intel MacBook Run Without A Battery

February 17, 2023 by 31 Comments

A long time ago, a laptop was a basic thing, and you could pretty much run one just by hooking up a power supply to the battery contacts. A modern MacBook is altogether fussier. However, when [Christophe] was stuck in the midst of a 2020 lockdown with no parts available, he found a way to get his damaged MacBook up and running without a battery.

The problem was brought about by a failing battery in the MacBook Pro 13″ from mid-2018, which swelled up and deformed the laptop’s case. Parts were unavailable, and the MacBook wouldn’t run at full speed without a battery fitted. That’s because with no battery present, the MacBook would send a BD_PROCHOT signal to the Intel CPU, telling it to slow down due to overheating, even when the chip was cool.

To get around the problem, [Christophe] used a tool called CPUTune. It allows fiddling with the various CPU settings of a MacBook. He deactivated the BD_PROCHOT signal, and also the CPU’s Turbo Boost feature. This ended the worst of the thermal throttling, and enabled semi-normal use of the machine.

It’s unclear why Apple would throttle the CPU with the battery disconnected. [Christophe]’s workaround got him back up and working again in the midst of a difficult period, regardless. We’ve seen some other great Macbook hacks before too, like this amazing save from serious water damage!

Thanks to [donaldcuckman] for the tip!]

Quantum Interconnects Get Faster

February 17, 2023 by 2 Comments

If you are a retrocomputer fan, you might remember when serial ports were a few hundred baud and busses ran at a few megahertz at the most. Today, of course, we have buses and fabric that can run at tremendous speeds. Quantum computing, though, has to start from scratch. One major problem is that jockeying quantum states around for any distance is difficult and slow. Part of it is that qubits decay rapidly, so you don’t have much time. They are also generally susceptible to noise and perturbation by outside forces. So many quantum machines today are limited by how much they can cram on one chip since there isn’t a good way to connect to another chip. The University of Sussex thinks it has improved the outlook for quantum interconnects with a technique they claim can move qubits around at nearly 2,500 links per second.

The technique, called UQ Connect, uses electric field links to connect multiple chips using trapped ions for qubits. If you want to read the actual paper, you can find it in Nature Communications.

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Fail Of The Week: Epic 312 Weeks Of Fixing A Broken Project

February 17, 2023 by 7 Comments

If a hacker guardian angel exists, then we’re sure he or she was definitely AWOL for six long years from [Aaron Eiche]’s life as he worked on perfecting and making his Christmas Countdown clock. [Aaron] started this binary clock project in 2016, and only managed to make it work as expected in 2022 after a string of failures.

In case you’d like to check out his completed project first, then cut the chase and head over to his Github repository for his final, working version. The hardware is pretty straightforward, and not different from many similar projects that we’ve seen before. A microcontroller drives a set of LED’s to show the time remaining until Christmas Day in binary format. The LEDs show the number of days, hours, minutes and seconds until Christmas and it uses two buttons for adjustments and modes. An RTC section wasn’t included in the first version, but it appeared and disappeared along the six year journey, before finding a spot in the final version.

The value of this project doesn’t lie in the final version, but rather in the lessons other hackers, specially those still in the shallow end of the pool, can learn from [Aaron]’s mistakes. Thankfully, the clock ornament is not very expensive to build, so [Aaron] could persevere in improving it despite his annual facepalm moments.

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Giant 3D Printed Excavator Is Awesome, But Needs Work

February 17, 2023 by 13 Comments

Many of us adored big construction machinery as children. Once we got past the cute, tiny age, it became uncool to gasp with shock and awe at diggers and bulldozers for some reason . [Ivan Miranda] still digs the big rigs, though, and built himself a giant 3D printed excavator that looks like brilliant fun. 

Why did Lego never make MegaTechnic blocks? [Ivan] shows us the true potential of bigger building blocks.
The build relies on [Ivan]’s giant 3D-printed Lego-like assembly kit. It lets him simply bolt together a bunch of plastic girders to make the key parts of the excavator, including the base and the digger arm itself. The digger arm is controlled with linear actuators of [Ivan’s] own design, which uses servos and threaded rod to do the job. They’re not as cool as hydraulics or pneumatics, but they get the job done well. For propulsion, [Ivan] built a tracked drive system again using his unique Lego-like blocks. The tracks were tedious to assemble, but add a lot to the excavators Awesomeness Quotient (AQ).

The overall build is quite slow, and more than a little fragile. It’s not quite ready for hardcore digging tasks. In reality, it’s serving as a test bed for [Ivan]’s 3D-printed building blocks that get better every time we see them. Video after the break.

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Like Chording But Not

February 17, 2023 by 3 Comments

Repetitive strain injuries (RSI) can be a real pain. You’ve got a shiny new laptop, and everything’s going smoothly, but suddenly you can’t use it without agonizing (as in typing-speed reducing) pain caused by years of keyboard bashing or just plain bad posture. All of us hacker types will likely have or will experience this at some point, and luckily there are many potential solutions.

[Zihao Wang] writes to show us kseqi, another chord-like textual input method, with a focus on the input sequences, as opposed to any particular mechanical arrangement of keys. The idea is to make use of two sets of independent inputs, where the sequence of actuation codes for the keystrokes to be emitted into the application.

Left-hand-first to select a column of the left character set. Right-hand-first selects the other set.

An example interface would be to arrange two sets of five keys as the input mechanism. One can arrange characters in a matrix. The left key is pressed and held first which selects a column (1 out of 5) then the right key is pressed to select a row, and thus a character. Next, you release in the same order, left, then right, to send the character.

Swapping left and right allows a different set of characters. In this simple scheme, fifty characters can be coded. Check out this web assembly demo for how this operates. Swapping out the physical inputs for a pair of joysticks is another option, which may be better for some folks with specific physical difficulties, or maybe because it just looks fun. As [Zihao] mentions in the write-up, the sequence order can be changed to code for other character sets, so this simple scheme can handle many more character codings than this simple example. All you have to do is remember them. Interested parties may want also wish to dig into the kseqi Rust crate for information.

Chorded keyboard projects are plentiful out there, here’s a nice Bluetooth-connected keeb, and another one that’s all wiggly.

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