Courtesy of [david.reid]

Bent PETG Fills A Nixie Gap

April 19, 2018 by 21 Comments

Have you ever thought that Nixie tubes are cool but too hard to control with modern electronics? And that they’re just too expensive? [david.reid] apparently thought so and decided to create his own version of a Nixie tube, and it doesn’t get much cheaper than this.

PETG Nixie Tube

While working on a 3D printed locomotive with his son, [david.reid] used clear PETG (Polyethylene Terephthalate Glycol) 3D printer filament to move light from LEDs to various parts of the locomotive. He found this was a success, but roughed up the outside of the filament to see what would happen. Lo and behold, a warm glow appeared on the surface of the tube! Like any good hacker, his next thought was of Nixie tubes, as you have seen in many clocks.

His basic idea is that with a little heat you can bend the filament into any shape that you like ([david.reid] uses custom molds). You then use some sandpaper to roughen up the outside wherever you’d like light to show, and add an LED at the bottom to light it up!

[david.reid] isn’t the first person to modernize Nixie Tubes. Over the years, we’ve seen them combined with Wi-Fi boards, individual LED segments, or even laser cutters & WS2812s!

Now’s a great time to get started on a project for the Hackaday Prize! If you’re looking for somewhere to start, we’d love to at least see your own take on a clock!

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When 4 + 1 Equals 8: An Advanced Take On Pointers In C

April 19, 2018 by 104 Comments

In our first part on pointers, we covered the basics and common pitfalls of pointers in C. If we had to break it down into one sentence, the main principle of pointers is that they are simply data types storing a memory address, and as long as we make sure that we have enough memory allocated at that address, everything is going to be fine.

In this second part, we are going to continue with some more advanced pointer topics, including pointer arithmetic, pointers with another pointer as underlying data type, and the relationship between arrays and pointers. But first, there is one particular pointer we haven’t talked about yet.

The one proverbial exception to the rule that pointers are just memory addresses is the most (in)famous pointer of all: the NULL pointer. Commonly defined as preprocessor macro (void *) 0, we can assign NULL like any other pointer.

Continue reading “When 4 + 1 Equals 8: An Advanced Take On Pointers In C” →

Completely Scratch-Built Electronic Speed Controller

April 19, 2018 by 13 Comments

Driving a brushless motor requires a particular sequence. For the best result, you need to close the loop so your circuit can apply the right sequence at the right time. You can figure out the timing using a somewhat complex circuit and monitoring the electrical behavior of the motor coils. Or you can use sensors to detect the motor’s position. Many motors have the sensors built in and [Electronoobs] shows how to drive one of these motors in a recent video that you can watch below. If you want to know about using the motor’s coils as sensors, he did a video on that topic, earlier.

The motor in question was pulled from an optical drive and has three hall effect sensors onboard. Having these sensors simplifies the drive electronics considerably.

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Mechanisms: Hook And Loop Fasteners

April 19, 2018 by 35 Comments

As a species, we’ve done a pretty good job at inventing some useful devices. But as clever as we think we are, given sufficient time, natural selection will beat us at our game at almost every turn. So it makes sense that many of our best inventions are inspired by nature and the myriad ways life finds to get DNA from one generation to the next.

Hook and loop fasteners are one such design cribbed from nature, and the story behind this useful mechanism is a perfect example that a prepared mind, good observation skills, and a heck of a lot of perseverance are what it takes to bring one of Mother Nature’s designs to market.

Editor’s Note: As some predicted in the comments section, we were contacted by representatives of Velcro Companies and asked to change all mentions in this article to either VELCRO® Brand Fastener or to use the generic “Hook and Loop” term. If it seems weird that we’re calling this hook and loop, now you know why.

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Unlock & Talk: Open Source Bootloader & Modem

April 19, 2018 by 13 Comments

During the early years of cell phones, lifespan was mainly limited by hardware (buttons wearing out, dropping phones, or water damage), software is a primary reason that phones are replaced today. Upgrades are often prompted by dissatisfaction with a slow phone, or manufacturers simply stopping updates to phone software after a few years at best. [Oliver Smith] and the postmarketOS project are working to fix the update problem, and have begun making progress on loading custom software onto cellphone processors and controlling their cellular modems. Continue reading “Unlock & Talk: Open Source Bootloader & Modem” →

Raspberry Pi W Antenna Analysis Reveals Clever Design

April 19, 2018 by 25 Comments

The old maxim is that if you pay peanuts, you get a monkey. That’s no longer true, though: devices like the Raspberry Pi W have shown that a $10 device can be remarkably powerful if it is well designed. You might not appreciate how clever this design is sometimes, but this great analysis of the antenna of the Pi W by [Carl Turner, Senior RF Engineer at Laird Technology] might help remind you.

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Browsing Modern Day BBS On The Epson PX-8 Laptop

April 18, 2018 by 24 Comments

As you read this, there are still people chatting away on Bulletin Board Systems all over the world. Running on newly written software and without the need to actually use a dial-up modem, these (slightly) more modern takes on the BBSs of yore can be compelling diversion for those who might want to decompress a bit from contemporary social networks.

[Blake Patterson] is one of these people, and he writes in to tell us about his recent experiments with using a particularly gorgeous example the Epson PX-8 “Geneva” laptop on modernized BBSs. The form factor of the device makes it a fairly convenient client for chatting, despite the somewhat unusual screen. Luckily, modern BBS software is able to cope with the PX-8’s 80 character by 8 line LCD display, it’s just a matter of getting the thing online.

The trick is tethering the PX-8 to a Linux machine as a serial terminal. [Blake] had to build a serial cable for the laptop, and then used a basic USB-to-serial converter to get it connected to a Raspberry Pi. Once you’ve logged in over serial, you can simply fire off a telnet command to connect to the BBS of your choice. In the video after the break, he demonstrates what it’s like browsing and chatting on a BBS using the PX-8. The screen certainly takes a bit of getting used to, but actually works fairly well given the nature of the BBS interface.

[Blake] recently gave us a look at a Wi-Fi “modem” for retro computers based on the ESP8266, if you’d rather cruise your favorite BBS without a dangling Pi.

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