A picture of the bottom of the Pi 4 PCB, showing the three points you need to use to tap into the Pi 4 I2C bus going to the PMIC

Dead Raspberry Pi Boards, PMICs, And New Hope

March 24, 2023 by 22 Comments

Since the Raspberry Pi 3B+ release, the Pi boards we all know and love gained one more weakpoint – the PMIC chip, responsible for generating all the power rails a Pi needs. Specifically, the new PMIC was way more vulnerable to shorting 5V and 3.3V power rails together – something that’s trivial to do on a Raspberry Pi, and would leave you with a bricked board. Just replacing the PMIC chip, the MxL7704, wouldn’t help since the Raspberry Pi version of this chip is customized – but now, on Raspberry Pi forums, [Nefarious19] has reportedly managed to replace it and revive their Pi.

First off, you get a replacement PMIC and reflow it – and that’s where, to our knowledge, people have stopped so far. The next step proposed by [Nefarious19] is writing proper values into the I2C registers of the PMIC. For that, you’d want a currently-alive Pi – useful as both I2C controller for writing the values in, and as a source of known-good values. That said, if you go with the values that have been posted online, just having something like a Pi Pico for the I2C part ought to be enough.

[Nefarious19] reports a revived Pi, and this is way more hopeful than the “PMIC failures are unfixable” conclusion we’ve reached before. The instructions are not quite clear – someone else in the thread reports an unsuccessful attempt doing the same, and it might be that there’s a crucial step missing in making the values persist. However, such an advancement is notable, and we trust our readers to take the lead.

A week ago, [Mangy_Dog] on Hackaday Discord brought up fixing Raspberry Pi boards – given that the Raspberry Pi shortages are still an issue, digging up your broken Pi and repairing it starts making sense budget-wise. It’s no longer the ages where you could buy broken Pi boards by the hundred, and we imagine our readers have been getting creative. What are your experiences with fixing Raspberry Pi boards?

The Keychain 6809

March 24, 2023 by 16 Comments

When you think of tiny microcontroller boards, you probably think of a modern surface mount processor. Not [Andreas Jakob]. His 5×5 cm keychain computer rocks a 6809 CPU at a blistering 1 MHz or, if you prefer, a 6309 that runs at 5 MHz. The RAM — all 32K — is in a SMD package to make it fit, but the board also sports a 27C256 EPROM which means that chip and the CPU take up most of the PCB.

As you might expect, there’s not much else on the board. It doesn’t hurt, too, that the PCB is a 6-layer board. The board features a USB C port for power and data, but we didn’t see the USB interface chip on the schematic until we opened it in Easy EDA using the button that says “open in editor.” The schematic says it is sheet 1 or 1, but there are actually two additional “tabs” you can only see in the editor with the apparently missing pieces.

Continue reading “The Keychain 6809” →

Enjoy An Open-Source Espresso

March 24, 2023 by 15 Comments

One of the core principles of the open-source movement is that anyone who wants to build on a piece of work, in whatever way they want, is easily able to. With source code freely available, the original project can be expanded upon, modified, updated, or simply looked at and used as inspiration. Usually we think about this in the realm of software freedom, but hardware is an important component as well. And not just electronics hardware, either. [Norm] demonstrates this espresso machine which was built on these open-source foundations.

The project takes some inspiration from the open-source Gaggiuino project, which was another build that modified an entry-level espresso maker with finer control over temperature and pressure. [Norm] was not willing to sacrifice his espresso machine for this cause, though, which is how this machine with its cobbled-together hardware came to be. An older machine with some worn parts was sacrificed to the coffee gods instead, making use of its pumps, boiler, and a few other bits of hardware especially from the hydraulics system. The software control is built around the Gaggiuino project, and includes a custom control board for user interface.

Right now the coffee maker does indeed work, but [Norm] hopes to make some improvements to the device including adding an enclosure of some sort, both to prevent accidental contact with the boiler and to give it a sleek, professional look. We kind of like it the way it is, while acknowledging that it isn’t quite ready for commercial production like this. It has a similar industrial feel as this espresso machine we featured a few years ago that is made out of old engine components.

Plan To Jam Mobile Phones In Schools Is Madness

March 24, 2023 by 329 Comments

Mobile phones in schools. If you’re a teacher, school staffer, or a parent, you’ve likely got six hundred opinions about this very topic, and you will have had six hundred arguments about it this week. In Australia, push has come to shove, and several states have banned the use of mobile phones during school hours entirely. Others are contemplating doing the same.

In the state of New South Wales, the current opposition party has made it clear it will implement a ban if elected. Wildly, the party wants to use mobile phone jamming technology to enforce this ban whether students intend to comply or not. Let’s take a look at how jammers work in theory, and explore why using them in schools would be madness in practice.

Continue reading “Plan To Jam Mobile Phones In Schools Is Madness” →

Hackaday Podcast 211: Pocket Sundial, Origami Llama, PCB Spacemouse

March 24, 2023 by 3 Comments

This week, Editor-in-Chief Elliot Williams and Contributor Emeritus Kristina Panos chewed the fat about the coolest hacks of the previous week. But first, a bit of news — our Low Power Challenge fizzled out this week, and boy did we have a lot of entries at the last minute. We love to see it though, and we’re going to get judging ASAP.

Don’t forget, this weekend is Hackaday Berlin! Livestreaming for this one may be iffy, but we’ll have the talks up for you eventually, so don’t fret too much if you can’t make it in the flesh this time.

Kristina definitely got What’s That Sound this week, but her answer will of course be bleeped out. Then it’s on to the hacks, beginning with a 6-DoF controller that does everything in interesting ways and a printed shredder that eats like a goat. From there we cover bolt dispensers, coffee grinders with Bluetooth weighing, camera calibration, and a $50 pen plotter that’s definitely a hack. Finally, we discuss the virtues of physicality when it comes to SIM cards and recorded music.

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!

And/or download it and listen offline.

Where to Follow Hackaday Podcast

Places to follow Hackaday podcasts:

Continue reading “Hackaday Podcast 211: Pocket Sundial, Origami Llama, PCB Spacemouse” →

Low-Power Challenge: Making An Analog Clock Into A Calendar With A 50-Year Life

March 24, 2023 by 24 Comments

You have to be pretty ambitious to modify a clock to run for 50 years on a single battery. You also should probably be pretty young if you think you’re going to verify your power estimates, at least in person. According to [Josh EJ], this modified quartz analog clock, which ticks off the date rather than the time, is one of those “The March of Time” projects that’s intended to terrify incentivize you by showing how much of the year is left.

Making a regular clock movement slow down so that what normally takes an hour takes a month without making any mechanical changes requires some clever hacks. [Josh] decided to use an Arduino to send digital pulses to the quartz movement to advance the minute hand, rather than let it run free. Two pulses a day would be perfect for making a 30-day month fit into a 60-minute hour, but that only works for four months out of the year. [Josh]’s solution was to mark the first 28 even-numbered minutes, cram 29, 30, and 31 into the last four minutes of the hour, and sort the details out in code.

As for the low-power mods, there’s some cool wizardry involved with that, like flashing the Arduino Pro Mini with a new bootloader that reduces the clock speed to 1 MHz. This allows the microcontroller and RTC module to run from the clock movement’s 1.5 V AA battery. [Josh] estimates a current draw of about 6 μA per day, which works out to about 50 years from a single cell. That’s to be taken with a huge grain of salt, of course, but we expect the battery will last a long, long time.

[Josh] built this clock as part of the Low-Power Challenge contest, which wrapped up this week. We’re looking forward to the results of the contest — good luck to all the entrants!

2023 Hackaday.io Low-Power Challenge

This Week In Security: USB Boom! Acropalypse, And A Bitcoin Heist

March 24, 2023 by 4 Comments

We’ve covered a lot of sketchy USB devices over the years. And surely you know by now, if you find a USB drive, don’t plug it in to your computer. There’s more that could go wrong than just a malicious executable. We’ve covered creative and destructive ideas here on Hackaday, from creative firmware to capacitors that fry a machine when plugged in. But what happened to a handful of Ecuadorian journalists was quite the surprise. These drives went out with a bang.

That is, they literally exploded. The drives each reportedly contained a pellet of RDX, a popular explosive in use by militaries since the second World War. There have been five of these hyperactive USB devices located so far, and only one actually detonated. It seems that one only managed to trigger half of its RDX payload. Because of this, and the small overall size of a USB drive, the explosion was more comparable to a firecracker than a bomb. Continue reading “This Week In Security: USB Boom! Acropalypse, And A Bitcoin Heist” →