Turning A Chromebox Into A Proper Power-Efficient PC

Google’s ChromeOS and associated hardware get a lot of praise for being easy to manage and for providing affordable hardware for school and other educational settings. It’s also undeniable that their locked-down nature forms a major obstacle and provides limited reusability.

That is unless you don’t mind doing a bit of hacking. The Intel Core i3-8130U based Acer CXI3 Chromebox that the [Hardware Haven] YouTube channel got their mittens on is a perfect example.

The Acer CXI3 in all its 8th-gen Intel Core i3 glory. (Credit: Hardware Haven, YouTube)
The Acer CXI3 in all its 8th-gen Intel Core i3 glory. (Credit: Hardware Haven, YouTube)

This is a nice mini PC, with modular SODIMM RAM, an NVMe storage M.2 slot as well as a slot for the WiFi card (or SATA adapter). After resetting the Chromebox to its default configuration and wiping the previous user, it ran at just a few watts idle at the desktop. As this is just a standard x86_64 PC, the only thing holding it back from booting non-ChromeOS software is the BIOS, which is where [MrChromebox]‘s exceedingly useful replacement BIOSes for supported systems come into play, with easy to follow instructions.

Reflashing the Acer CXI3 unit was as easy as removing the write-protect screw from the mainboard, running the Firmware Utility Script from a VT2 terminal (Ctrl+Alt+F2 on boot and chronos as login) and flashing either the RW_LEGACY or UEFI ROM depending on what is supported and desired. This particular Chromebox got the full UEFI treatment, and after upgrading the NVMe SSD, Debian-based Proxmox installed without a hitch. Interestingly, idle power dropped from 2.6 watts under ChromeOS to 1.6 watts under Proxmox.

If you have a Chromebox that’s supported by [MrChromebox], it’s worth taking a poke at, with some solutions allowing you to even dualboot ChromeOS and another OS if that’s your thing.

Continue reading “Turning A Chromebox Into A Proper Power-Efficient PC”

You Wouldn’t Download A Helmet?

Odds are, if you have ridden a bicycle for any amount of time, you have crashed. Crashes are fast, violent and chaotic events that leave you confused, and very glad to have a helmet. But what if there was another way of protecting your head? [Seth] decided to find out by taking a look at the Hövding airbag helmet.

The Hövding sits around your neck and looks somewhat akin to a neck pillow. It uses accelerometers situated in the fore and aft of the device to detect what it thinks is a crash. If a crash is detected, it will release a charge of compressed helium to inflate an airbag that wraps around the user’s head protecting a larger amount of the head then a traditional helmet. It also inflates around the wearer’s neck providing neck bracing in the impact further improving safety. The inflation process is incredibly fast and violent, very much akin to a car’s airbag. [Seth] demonstrated this on the process on two occasions to great effect, and to his amazement. While the idea of relying on computers to protect your head may sound ridiculous, studies have shown that the Hövding is safer than a regular helmet in certain situations.

Continue reading “You Wouldn’t Download A Helmet?”

What’s An LCR Databridge?

[Thomas Scherrer] has an odd piece of vintage test equipment in his most recent video. An AIM LCR Databridge 401. What’s a databridge? We assume it was a play on words of an LCR bridge with a digital output. Maybe. You can see a teardown in the video below.

Inside the box is a vintage 1983 Z80 CPU with all the extra pieces. The device autoranges, at least it seems as much. However, the unit locks up when you use the Bias button, but it isn’t clear if that’s a fault or if it is just waiting for something to happen.

The teardown starts at about six minutes in. Inside is a very large PCB. The board is soldermasked and looks good, but the traces are clearly set by a not-so-steady hand. In addition to AIM, Racal Dana sold this device as a model 9341. The service manual for that unit is floating around, although we weren’t able to download it due to a server issue. A search could probably turn up copies.

Continue reading “What’s An LCR Databridge?”

A Web Based Controller For Your Garage Door

Garage doors! You could get out of your vehicle and open and close them yourself, but that kinda sucks. It’s much preferable to have them raise and lower courtesy some mechanical contrivance, and even better if that is controlled via the web. [Juan Schiavoni] shows us how to achieve the latter with their latest project.

The web-based controller is based around a Xiao ESP32 microcontroller board, chosen for its baked-in WiFi connectivity. It’s set up to host its own web interface which you can login to with a password via a browser. If you have the correct authorization, you can then hit a button to open or close the garage door.

To interface the ESP32 with the garage door itself, [Juan] went the easy route. To trigger opening or closing the door, the ESP32 merely flicks an IO pin to toggle a transistor, which is hooked up to the button of the original garage door opener. Meanwhile, the ESP32 is also hooked up with a magnetic switch which is activated by a magnet on the garage door itself. This serves as a crude indicator as to the current status of the door—whether currently open or closed. This is crucial to ensure the indicated door status shown in the web app remains synced with the status of the door in reality.

It’s a simple project, and reminds us that we needn’t always do things the hard way. [Juan] could have figured out how to hook the ESP32 up with some radio chips to emulate the original garage door opener, but why bother? hooking it up to the original remote was far easier and more reliable anyway. We’ve seen a good few garage door hacks over the years; if you’ve got your own unique take on this classic, don’t hesitate to notify the tipsline!

[Thanks to Stillman for the tip!]

Thermal Monocular Brings The Heat At 10X

[Project 326] is following up on his thermal microscope with a thermal telescope or, more precisely, a thermal monocular. In fact, many of the components and lenses in this project are the same as those in the microscope, so you could cannibalize that project for this one, if you wanted.

During the microscope project, [Project 326] noted that first-surface mirrors reflect IR as well as visible light. The plan was to make a Newtonian telescope for IR instead of light. While the resulting telescope worked with visible light, the diffraction limit prevented it from working for its intended purpose.

Continue reading “Thermal Monocular Brings The Heat At 10X”

The frame of a delta 3D printer is shown. The toolhead of the 3D printer does not have a hotend installed, but instead has a frame with a circular hole in the middle.

A Toolchanging Delta 3D Printer

We’ve seen quite a few delta 3D printers, and a good number of toolchanging printers, but not many that combine both worlds. Fortunately, [Ben Wolpert]’s project fills that gap with a particularly elegant and precise delta toolchanger.

The hotend uses three steel spheres and triangular brackets to make a repeatable three-point contact with the toolhead frame, and three pairs of corresponding magnets hold it in place. The magnets aren’t in contact, and the three magnets on the toolhead are mounted in a rotating ring. A motorized pulley on the printer’s frame drives a cable which runs through a flexible guide and around the rotating ring.

The whole setup is very reminiscent of the Jubilee toolchanging system, except that in this case, the pulley rotates the ring of magnets rather than a mechanical lock. By rotating the ring of magnets about 60 degrees, the system can move the pairs of magnets far enough apart to remove the hotend without much force.

The rest of the toolchanging system is fairly straightforward: each tool’s parking area consists of two metal posts which slot through corresponding holes in the hotend’s frame, and the motherboard uses some RepRapFirmware macros to coordinate the tool changes. The only downside is that a cooling fan for the hotend still hadn’t been implemented, but a desk fan seemed to work well enough in [Ben]’s tests. The files for the necessary hardware and software customizations are all available on GitHub.

We’ve only seen a similar toolchanging system for a delta printer once before, but we have seen a great variety of toolchangers on the more common Cartesian systems. Don’t like the idea of changing extruders? We’ve also seen a multi-extruder printer that completely eliminates tool switching.

Continue reading “A Toolchanging Delta 3D Printer”

Remembering Memory: EMS, And TSRs

You often hear that Bill Gates once proclaimed, “640 kB is enough for anyone,” but, apparently, that’s a myth — he never said it. On the other hand, early PCs did have that limit, and, at first, that limit was mostly theoretical.

After all, earlier computers often topped out at 64 kB or less, or — if you had some fancy bank switching — maybe 128 kB. It was hard to justify the cost, though. Before long, though, 640 kB became a limit, and the industry found workarounds. Mercifully, the need for these eventually evaporated, but for a number of years, they were a part of configuring and using a PC.

Why 640 kB?

The original IBM PC sported an Intel 8088 processor. This was essentially an 8086 16-bit processor with an 8-bit external data bus. This allowed for cheaper computers, but both chips had a strange memory addressing scheme and could access up to 1 MB of memory.

In fact, the 8088 instructions could only address 64 kB, very much like the old 8080 and Z80 computers. What made things different is that they included a number of 16-bit segment registers. This was almost like bank switching. The 1 MB space could be used 64 kB at a time on 16-byte boundaries.

So a full address was a 16-bit segment and a 16-bit offset. Segment 0x600D, offset 0xF00D would be written as 600D:F00D. Because each segment started 16-bytes after the previous one, 0000:0020, 0001:0010, and 0002:0000 were all the same memory location. Confused? Yeah, you aren’t the only one.

Continue reading “Remembering Memory: EMS, And TSRs”