Model Railroad Engine Gets A Tiny OLED Rollsign While Showing Off Tidy Protoboard Skills

August 19, 2020 by 4 Comments

When catching public transport, it’s very helpful if the bus or train in question has a large display indicating the route or destination. While many transit lines now rely on flipdot or LED displays, the classic rollsign still gets the job done. [diorama111] wanted to emulate this on a model railroad, and set about building a simulacrum at tiny scale.

Intended to suit an HO-scale model train, the build makes use of a tiny 0.6 inch NHD-0.6-6464G OLED display. It’s wired up with a boost converter for power and hooked up to a tiny circuit consisting of an ATMEGA328p and an infrared receiver. The microcontroller is responsible for receiving commands from the remote control, and displaying the appropriate image on the screen. The hidden beauty of this one is well shown in the video below as [diorama111] cleanly and meticulously assembles the circuit on protoboard with just an iron and tweezers.

What makes this project great is how neatly it’s integrated into the body of the train. Nestled inside the locomotive, it almost looks like a stock part of the model. While the nature of the OLED display does come across a touch anachronistic, implementing the vertical scroll really does add a lot to the final effect.

We love to see creative scale modelling projects, and we’ve seen some great work from [diorama111] in the past, too. Video after the break.

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Restoring Commodore’s Unloved Plus/4

August 18, 2020 by 9 Comments

The Commodore Plus/4 was not loved by the marketplace after its launch in 1984. Despite its namesake feature of having productivity programs built in, its lack of compatibility with Commodore 64 software and oddball status meant that it struggled to find acceptance. However, like so many retro computers, it maintains a following to this day. [Drygol] had collected a total of eight neglected units, and set to giving them a full workover.

First on the docket is cleaning, and [Drygol] makes short work of disassembling the computers and removing decades of dirt and dust. Keycaps are treated with Retrobright to restore their original color. The black styling of the case means it gets a simple wash down instead, and then a rub with thin oil to restore the plastic’s original sheen.

[Drygol] steps through various popular hacks for the platform too, from 6510 CPU replacements for the often-failing 7501 and 8501, to SD2IEC card interfaces to replace the much-maligned storage original storage options. Damaged keyboard studs are replaced with hacked-up Amiga parts, while LEDs that are long out of production are swapped out for cut-down modern parts.

The impressive thing is just how much community support there is for an also-ran Commodore that never truly caught the public’s eye. Efforts are ongoing, too, with projects like THED aiming to reproduce some of the custom chips used on the platform.

We’ve featured posts on the engineering that goes into Commodore’s 8-bit computers as well, like this excellent piece from [Bil Herd] on the story of the Commodore 128. Of course, if you’re working your own wonders with retro hardware, you know who to call.

Encouragement Machine Battles Your Inner Bully

August 18, 2020 by 1 Comment

We would be preaching to the choir if we told you that fear is the action killer when it comes to the challenge of new projects in uncharted territory. Everyone who reads Hackaday knows that it takes mettle to forge through the self-doubt as we push ourselves to new engineering heights.

[JBV Creative] hears the voice, too: the one that says you can’t build that thing, it’s too difficult/useless. He knows that both creativity and anti-creativity stem from the same source — the powerful human mind that dreams up these projects in the first place.

The Encouragement Machine combines the two in a piece that engineers art from garbage, aka negative thoughts. It works by first acknowledging the most basal of discouraging thoughts — an important step of the process — and then it simply trims away the negativity.

This machine uses a stepper motor to feed receipt paper underneath a custom stamp that says YOU CAN’T DO IT. Then it passes the paper through a pair of servo-driven scissors that snip off the apostrophe-t.

Ironically or not, [JBV Creative] ran into a few issues with this build, but managed to muster up enough moxie to work through the problems without encouraging slips of paper. We have to wonder how much more smoothly the next project will go given all the positivity he now has on-demand.

[JBV] doesn’t delve into the electronics much, but it looks like an Arduino and a motor driver to us. We totally dig the design — it looks like an electrical substation or rocket launch pad that happens to have a Ferris wheel. Step right up and check out the build video after the break.

Generic encouragement is great all-purpose attitude adjuster, but what if you want more specific sentiments? Here’s an affirmation mirror that will help you believe whatever you program into the scrolling display.

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DropController Sets The Bar For Documentation

August 18, 2020 by 4 Comments

dropController has the kind of documentation we wish would spontaneously generate itself whenever we build something. [Martyn Currey] built a robust rig for water droplet photography, and we don’t want to dismiss the hardware, but the most impressive part might be the website. It might not be very fancy, but it’s thorough and logically organized. You can find parts lists, assembly manuals, tutorials, sketches, and schematics. If only all the projects that came our way were so well detailed.

Water droplet photography is pretty cool, although freehanding it will make your patience fall faster than 9.81 m/s². The concept is that a solenoid valve will flicker open to release a drop of water, wait for a certain number of microseconds, and then trigger your DSLR via a wired remote cable. The tricky part comes from controlling as many as six valves and three flashes. We don’t have enough fingers and toes to press all those buttons.

The bill of materials contains many commonly available parts like an Arduino Nano, an LM2596 voltage regulator, some MOSFETS, an HC-06 Bluetooth module, plus standard audio connectors to hook everything up. Nothing should break the bank, but if money is not an issue, [Martyn] sells kits and complete units.

Waterdrop controllers are not the newest kids on the block, and strobe photography is a time-honored tradition.

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Share Your Clipboard Across Machines Using MQTT

August 18, 2020 by 21 Comments

Many of us regularly move from one computer to another for work, play, and hacking; every now and then finding yourself wishing you could copy something on one machine and paste on another without additional steps in between. [Ayan Pahwa] was well acquainted with this frustration, so he created AnywhereDoor, a cross-platform clipboard sharing utility that uses MQTT.

Some cloud-based solutions already exist to do this, but that means sending your private clipboard data to someone else’s server. Not keen on that idea, [Ayan]’s solution makes use of a MQTT broker that can run anywhere on the local network, and lightweight python clients to run on Mac, Windows and Linux. The client checks your clipboard at specified intervals, and publishes new data to a topic on the broker, to which all the clients are subscribed. The data is end-to-end encrypted using Fernet symmetrical key encryption, so the data won’t be readable to anyone else on the network. Currently, AnywhereDoor only supports copying text, but media is planned for a future version.

We like the relative simplicity of the utility, and see it being very handy for hackers bouncing between machines in the lab. Simple software utilities that solve a specific and real problem can are very useful, like a wiring documentation tool, or Kicad to isolation routing patchwork converter.

Open Exosuit Project Helps Physically Challenged Put One Foot In Front Of Another

August 18, 2020 by 6 Comments

Humans make walking look simple, but of course that’s an illusion easily shattered by even small injuries. Losing the ability to walk has an enormous impact on every part of your day, so rehabilitative advances are nothing short of life-changing. The Open Exosuit for Differently Abled project is working feverishly on their Hackaday Prize entry to provide a few different layers of help in getting people back on their feet.

We’ve seen a number of exosuit projects in the past, and all of them struggle in a few common places. It’s difficult to incorporate intuitive user control into these builds, and quite important that they stay out of the way of the user’s own balance. This one approaches those issues with the use of a walker that both provides a means of steadying one’s self, and facilitates sending commands to the exosuit. Using the OLED screen and buttons incorporated on the walker, the user can select and control the walking, sitting, and standing modes.

The exoskeleton is meant to provide assistance to people with weakness or lack of control. They still walk and balance for themselves, but the hope is that these devices will be an aid at times when human caregivers are not available and the alternative would be unsteady mobility or complete loss of mobility. Working with the assistive device has the benefit of continuing to make progress in strengthening on the march to recovery.

The team is hard at work on the design, and with less than two weeks left before the entry deadline of the 2020 Hackaday Prize, we’re excited to see where the final push will bring this project!

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Linux-Fu: One At A Time, Please! Critical Sections In Bash Scripts

August 18, 2020 by 12 Comments

You normally think of a critical section — that is, a piece of a program that excludes other programs from using a resource — as a pretty advanced technique. You certainly don’t often think of them as part of shell scripting but it turns out they are surprisingly useful for certain scripts. Most often, a critical section is protecting some system resource like a shared memory location, but there are cases where a shell script needs similar protection. Luckily, it is really easy to add critical sections to shell scripts, and I’ll show you how.

Sometimes Scripts Need to Be Selfish

One very common case is where you want a script to run exactly one time. If the same script runs again while the original is active, you want to exit after possibly printing a message. Another common case is when you are updating some file and you need undisturbed access while making the change.

That was actually the case that got me thinking about this. I have a script — may be the subject of a future Linux-Fu — that provides dynamic DNS by altering a configuration file for the DNS server. If two copies of the script run at the same time, it is important that only one of them does modifications. The second copy can run after the first is totally complete.

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