The Perfect Pi Pico Portable Computer

February 22, 2025 by Adam Fabio 24 Comments

[Abe] wanted the perfect portable computer. He has a DevTerm, but it didn’t quite fit his needs. This is Hackaday after all, so he loaded up his favorite CAD software and started designing. The obvious choice here would be a Raspberry Pi. But [Abe] didn’t want to drop in a Linux computer — he was going for something a bit smaller.

An RP2040 Pico would be a perfect fit. Driving a display with the Pico can be eat a lot of resources though. The solution was a PicoVision from Pimoroni. PicoVision uses two RP2040 chips. One drives an HDMI port, while the other is free to run application software. This meant a standard HDMI screen could be used.

The keyboard was a bit harder. After a lot of searching, [Abe] found an IR remote designed for smart TVs. The QWERTY keyboard was the perfect size but didn’t have an interface he could use. He fixed that with an adapter PCB including an I2C GPIO expander chip. A bit of I2C driver software later, and he had a working input keyboard.

Hardware doesn’t do anything without software though. The software running on the handheld is called Slime OS, and the source is available at [Abe’s] GitHub. It’s a launcher, with support for applications written in python. [Abe] has a few basic demos working, but he’s looking for help to get more features up and running.

Although it wasn’t quite what [Abe] was after, our own [Donald Papp] came away fairly impressed when he gave the DevTerm a test drive back in 2022. Something to consider if you’re looking for a Linux handheld and not quite ready to build one yourself.

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Software Lets You Paint Surface Patterns On 3D Prints

January 25, 2025 by Adam Fabio 19 Comments

Just when you think you’ve learned all the latest 3D printing tricks, [TenTech] shows up with an update to their Fuzzyficator post-processing script. This time, the GPL v3 licensed program has gained early support for “paint-on” textures.

Fuzzyficator works as a plugin to OrcaSlicer, Bambu Studio, and PrusaSlicer. The process starts with an image that acts as a displacement map. Displacement map pixel colors represent how much each point on the print surface will be moved from its original position. Load the displacement map into Fuzzyficator, and you can paint the pattern on the surface right in the slicer.

This is just a proof of concept though, as [TenTech] is quick to point out. There are still some bugs to be worked out. Since the modifications are made to the G-code file rather than the model, the software has a hard time figuring out if the pattern should be pressed into the print, or lifted above the base surface. Rounded surfaces can cause the pattern to deform to fit the surface.

If you’d like to take the process into your own hands, we’ve previously shown how Blender can be used to add textures to your 3D prints.

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The Twisted History Of Ethernet On Twisted Pair Wiring

December 30, 2024 by Adam Fabio 55 Comments

We all take Ethernet and its ubiquitous RJ-45 connector for granted these days. But Ethernet didn’t start with twisted pair cable. [Mark] and [Ben] at The Serial Port YouTube channel are taking a deep dive into the twisted history of Ethernet on twisted pair wiring. The earliest forms of Ethernet used RG-8 style coaxial cable. It’s a thick, stiff cable requiring special vampire taps and lots of expensive equipment to operate.

The industry added BNC connectors and RG-58 coax for “cheapernet” or 10Base2. This reduced cost, but still had some issues. Anyone who worked in an office wired with 10Base2 can attest to the network drops whenever a cable was kicked out or a terminator was dropped.

The spark came when [Tim Rock] of AT&T realized that the telephone cables already installed in offices around the world could be used for network traffic. [Tim] and a team of engineers from five different companies pitched their idea to the IEEE 802.3 committee on Feb 14, 1984.

The idea wasn’t popular though — Companies like 3COM, and Digital Equipment Corporation had issues with the network topology and the wiring itself. It took ten years of work and a Herculean effort by IEEE committee chairwoman [Pat Thaler] to create the standard the world eventually came to know as 10Base-T. These days we’re running 10 Gigabit Ethernet over those same connectors.

For those who don’t know, this video is part of a much larger series about Ethernet, covering both history and practical applications. We also covered the 40th anniversary of Ethernet in 2020.

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Wire Rope: Never Saddle A Dead Horse

December 29, 2024 by Adam Fabio 26 Comments

If you’re into building large projects, you’ll eventually find yourself looking at wire rope. Multistrand steel wire used as antenna guy wires, bridge supports, and plenty of other uses. The [HowNot2] team tested an old rule of thumb for wire rope. “Never saddle a dead horse”.

Click through the break for more:

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Let It Snow With A Sub $100 Snowmaking Machine.

December 28, 2024 by Adam Fabio 29 Comments

[Mattmopar] figured out how to get a white Christmas even if the weather isn’t frightful. He built a simple DIY snow making machine with a few plumbing parts, and tools you probably already have. Snowmaking machines used on the ski slopes cost tens of thousands of dollars. Even the “low-cost” home versions are $400 and up.

[Matt] cut things down to the basics. Snowmaking requires two ingredients: Water and compressed air. The water is coming from a cheap electric pressure washer he found used. The air pressure is from an old air compressor. [Matt] is using his shop compressor – but even a cheap compressor will do fine.

The cold is an unforgiving environment though – so a few changes are needed. The trick is to use garden hose instead of air hose. Traditional air hose has a rather small hole. This leads to ice clogs coming from the compressor itself. A check valve also ensures that water from the pressure washer doesn’t back up into the compressor.

The nozzles are pressure washer nozzles. Two 40 degree nozzles for the water, and a 65 degree nozzle for the air/water mix. In true hacker style, the frame of the machine is a ladder, and the gun attached via zip-ties.

Of course you still need cold temperatures for this to work, but that’s not too hard in the winter months. Now if you have the opposite problem of too much snow, check out this self clearing concrete.

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The Bendix G-15 Runs 75,000 Lines Of Code

December 21, 2024 by Adam Fabio 16 Comments

There’s a Blue Bendix in Texas, and thanks to [Usagi Electric] it’s the oldest operating computer in North America. The Bendix G-15, a vacuum tube computer originally released in 1956, is now booting, and running code from paper tape. [David, aka Usagi] received the G-15 about a year ago from The System Source museum. The goal was to get the computer running so museum patrons could interact with a real tube computer. We’ve been following along since the project began.

[Usagi’s] latest G-15 video covers the last few problems on the road to running code. The biggest hurdle was the fact that the system wasn’t responding properly to the GO button on the typewriter. [Usagi] was able to isolate the issue down to a flip flop and then to a particular signal on an AND gate — the RC signal. The gate appeared to be bad, but swapping the entire circuit card multiple times had no effect. Something else had to be going on.

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ESP32 Hosts A USB Keyboard In This Typewriter

November 17, 2024 by Adam Fabio 14 Comments

Did you know the ESP32 can be a USB host? Well it can, and [Volos] uses host mode to build this fun little word processor.

The venerable ESP32 has a well-known USB device mode. Anyone who has programmed one has used it. A bit less known is the microcontroller’s ability to host USB devices. These days, operating as a USB device is relatively simple. But acting as a host is a much more complex task. The ESP32 has a software host that works — but only for Human Interface Devices (HID). Human interface devices generally are keyboards, mice, trackballs, and similar devices that handle data relatively slowly, forming the interface with us simple humans.

[Volos] uses the EspUsbHost Arduino library for this project. The library makes USB host mode simple to use. Another piece of the puzzle is the LCD board [Volos] picked. It has a dual-role USB Type-C port, meaning the hardware to switch roles is baked in. Other boards may require some modifications or special cables to make things work.

The software is the best part of this build. [Volos] implemented a simple word processor. It can save and load files from a microSD card and, of course, edit text — all controlled by a USB keyboard. He had to use a 4-bit palette to save memory. This gives the device a retro charm that reminds us of Don Lancaster’s TV Typewriter. The source for this and all of [Volos] projects can be found on GitHub. Now, all we need is a spell check that can fit in the memory constraints of the ESP32! We have to admit the chip has a lot of potential USB tricks.

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