Add A Host Of 8-Bit Processors To Your Arduino

Normally when we bring you news of a retrocomputing design, it will centre around a single processor. At its heart will be a 6502, a Z80, or perhaps a 6809. There will be a host of support chips, some memory as RAM or ROM, and a bunch of interfaces. [Erturk Kocalar]’s RetroShield project for the Arduino Mega breaks all of those rules, because it supports all three of those classic processors, has no support chips, no memory, and no external interfaces beyond the shield connection to the Mega. What on earth is going on!

A closer look reveals that the project is a set of shields that use the Mega’s power to emulate all the support chips and peripherals you’d have seen on the original hardware. And while it would be impressive to have a single board with support for all three CPUs, in fact there is a PCB for each one. But that makes it no less interesting a project for those with an interest in 8-bit processors, because the focus becomes the software rather than a quest to find out-of-production silicon.

So far there is some limited demo software, and his website goes into some detail on the interfacing and code required. The Arduino can only clock the 8-bit CPU at 95kHz in software which may sound a bit low to those familiar with 1980s home computers, but it’s best to think of this as an experimentation platform and give up dreams of playing Elite. An exciting prospect comes in giving the 8-bit machine access to Arduino shields, if improbable hardware is your bag.

If this has captured your interest, you might also wish to take a look at the $4 Z80 single board computer which has a similar ethos.

Arduino Drives Seventeen Stepper Motors, Carefully

It’s fair to say that building electronic gadgets is easier now than it ever has been in the past. With low-cost modular components, there’s often just a couple dozen lines of code and a few jumper wires standing between your idea and a functioning prototype. Driving stepper motors is a perfect example: you can grab a cheap controller board, hook it up to a microcontroller, and the rest is essentially just software. But recently [mechatronicsguy] wondered if even that was more hardware than was technically necessary to get the job done.

It’s not that he was intentionally looking to make things more complicated for himself, of course. His rationale was entirely economic; if you’re looking to drive a dozen or more stepper motors, even the “cheap” controllers can add up. So he started to wonder if he could skip the controller entirely and connect the stepper motor directly to the digital pins of an Arduino. Generally speaking this is a bad idea, but if you’re careful and are willing to take the risk, [mechatronicsguy] is living proof it’s possible

So what’s the trick to running a whopping seventeen individual stepper motors directly from the digital pins of an Arduino Mega? Well, to start with you’re not going to be running the beefy NEMA 17 motors like you might find in a 3D printer. [mechatronicsguy] is using the diminutive (and dirt cheap) 28BYJ-48, a light duty stepper used in many consumer products. Even with this relatively tiny motor, you need to crack open the case and cut a trace on the PCB to switch it from unipolar to bipolar.

Beyond that, you need to be careful. [mechatronicsguy] reports he’s had success running as many as ten of them at once, but realistically the fewer operating simultaneously the better. This is actually made easier due to the relatively poor specs of the 28BYJ-48 motor; its huge eleven degree step size means its not really susceptible to the same kind of slippage you’d get on a NEMA 17 when powered down. This means you can cut power to all but the actively moving motor and be fairly sure they’ll all stay where you left them.

With as popular as the 28BYJ-48 stepper is, there are several projects this “quick and dirty” method of interfacing could potentially work with. This small “barn door” star tracker is an obvious example, but we’ve also seen some very nice robotic arms built with these low-cost motors which could benefit from the technique.

Miniature 3D Printed Forklift is quite pallet-able

If you have a small logistics problem, we have the solution for you. [Leon] built a tiny little forklift with LED lighting, working forks, and remote control using a combination of 3D printing tech, some CNC work, and fine soldering skills.

The electronics for this build are based around a few servos and a pair of geared DC motors and are driven via an Arduino Mega. Connectivity and remote controllability are what you would expect from an Arduinified project. There’s an HC-05 Bluetooth module on the board and remote control is handled by a custom Android app.

Of note in this project are the forks that actually work, almost like a real forklift. This allows the mini Arduino forklift to pick up mini pallets, drop them somewhere, and have mini DIY enthusiasts come up to build mini-furniture for mini-Etsy, which will be prominently featured in the mini foyer of a mini two-story walkup. No, it’s not mini-gentrification; this mini forklift is helping the mini local economy.

You can check out the entire build video below, filmed in the usual maker demo method of speeding up the entire build process but somehow keeping the no-talking audio. We have a lot to thank [Jimmy DiResta] for, and it’s not just cinematography. All the files for this forklift are up on the Github should you want to build your own.

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Bad Apple!! Via The Arduino Mega

The Arduino Mega is a useful tool for the maker. Generally, once one has come up with plans for blinking LEDs that require more IO than is available on the Arduino Uno, one graduates to the Mega and goes for broke. However, it’s not typically what we’d consider as our first choice for video work. [Stephane] begs to differ, and coded this Bad Apple!! demo for the Arduino Mega 2560.

For those unfamiliar, video on the Arduino is actually somewhat of a solved problem – merely requiring a pair of resistors and some nifty code. The real meat of this hack is the video storage itself. It’s been done before, but by streaming data off an SD card or serial link. [Stephane] was determined to store everything on the Arduino itself, and thus the hack begun. Video data is stored as 1 bit per pixel, as it’s a simple black and white video as per the original inspiration. LZ77 compression was used to cram the data down without requiring too much RAM, which is a limited resource on the Mega. It’s video only, as the Mega is tapped out handling 3 minutes and 39 seconds of video storage, but future work may include syncing with a second Arduino to deliver the soundtrack.

It’s a hack that shows off [Stephane]’s ability to get impressive performance out of limited platforms. We’ve seen this before, with his excellent Star Fox port to the Arduboy. Video after the break.

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Superdeep Borehole Samples Create Non-boring Music

In the 1970s, the Soviet Union decided to dig a hole for science. Not just any hole, the Kola Superdeep Borehole reached a depth of over 12 kilometers, the deepest at the time and the second deepest today by just a few meters. Since this was one of the few holes dug this deep that wasn’t being drilled for oil, the project was eventually abandoned. [Dmitry] was able to find some core samples from the project though, and he headed up to the ruins of the scientific site with his latest project which produces musical sounds from the core samples.

The musical instrument uses punched tape, found at the borehole site, as a sort of “seed” for generating the sounds. Around the outside of the device are five miniature drilling rigs, each holding a piece of a core sample from the hole. The instrument uses the punched tape in order to control the drilling rigs, and the sound that is created is processed by the instrument and amplified, which creates some interesting and rather spooky sounds. The whole thing is controlled by an Arduino Mega.

Not only does the project make interesting sounds from a historically and scientifically significant research station and its findings, but the project has a unique and clean design that really fits its environment at the abandoned facility. The other interesting thing about this project is that, if you want to make the trek, anyone can go explore the building and see the hole for themselves. If you’re wondering about the tools that could be used to make a hole like this, take a look at this boring project.

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An Arduino Powered Tank Built To Pull Planes

Surely our readers are well aware of all the downsides of owning an airplane. Certainly the cost of fuel is a big one. Birds are a problem, probably. That bill from the traveling propeller sharpener is a killer too…right? Alright fine, we admit it, nobody here at Hackaday owns an airplane. But probably neither do most of you; so don’t look so smug, pal.

But if you did own a plane, or at least work at a small airport, you’d know that moving the things around on the ground is kind of a hassle. Smaller planes can be pulled by hand, but once they get up to a certain size you’ll want some kind of vehicle to help out. [Anthony DiPilato] wanted a way to move around a roughly 5,200 pound Cessna 310, and decided that all the commercial options were too expensive. So he built his own Arduino powered tank to muscle the airplane around the tarmac (if site is down try Google cache), and his journey from idea to finished product is absolutely fascinating to see.

So the idea here is pretty simple. A little metal cart equipped with two beefy motors, an Arduino Mega, a pair of motor controllers, and a HC-08 Bluetooth module so you can control it from your phone. How hard could it be, right? Well, it turns out combining all those raw components into a little machine that’s strong enough to tow a full-scale aircraft takes some trial and error.

It took [Anthony] five iterations before he fine tuned the design to the point it was able to successfully drag the Cessna without crippling under the pressure. The early versions featured wheels, but eventually it was decided that a tracked vehicle would be required to get enough grip on the blacktop. Luckily for us, each failed design is shown along with a brief explanation about what went wrong. Admittedly it’s unlikely any of us will be recreating this particular project, but we always love to see when somebody goes through the trouble of explaining what went wrong. When you include that kind of information, somewhere, somehow, you’re saving another maker a bit of time and aggravation.

Hackers absolutely love machines with tank treads. From massive 3D printed designs to vaguely disturbing humanoid robots, there’s perhaps no sweeter form of locomotion in the hacker arsenal.

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Roll A Black Box For Your Wheels

Telemetric devices for vehicles, better known as black boxes, cracked the consumer scene 25 years ago with the premiere of OnStar. These days, you can get one for free from your insurance company if you want to try your luck at the discounts for safe driving game. But what if you wanted a black box just to mess around with that doesn’t share your driving data with the world? Just make one.

[TheForeignMan]’s DIY telematics box was designed to pull reports of the car’s RPM, speed, and throttle depression angle through the ODBII port. An ODBII-to-Bluetooth module sends the data to an Arduino Mega and logs it on an SD card along with latitude and longitude from a NEO-6M GPS module. Everything is powered by the car’s battery through a cigarette lighter-USB adapter.

He’s got everything tightly wrapped up inside a 3D printed box, which makes it pretty hard to retrieve the SD card. In the future, he’d like to send the data to a server instead to avoid accidentally dislodging a jumper wire.

If this one isn’t DIY enough for you to emulate, start by building your own CAN bus reader.