Back To The Future Prop Can Tell When It Hits 88 MPH

August 17, 2022 by Tom Nardi 8 Comments

Obviously, the most iconic piece of fictional hardware from the Back to the Future films is Doc Brown’s DeLorean DMC-12 time machine. But we’d have to agree with [Jason Altice] of CodeMakesItGo that the second-most memorable gadget is the modified Futaba remote control used to control the DeLorean from a distance. Now, thanks to his detailed build guide, you can build your own version of the time machine’s controller — complete with working speed readout.

Now to be clear, [Jason] isn’t claiming that his build is particularly screen accurate. It turns out that the actual transmitter used for the prop in the film, the Futaba PCM FP-T8SGA-P, has become difficult to find and expensive. But he argues that to the casual observer, most vintage Futaba transmitters are a close enough match visually. The more important part is recreating the extra gear Doc Brown bolted onto his version. Continue reading “Back To The Future Prop Can Tell When It Hits 88 MPH” →

Want To Use A Classic Mac Mouse On A Modern Computer? No? Here’s How To Do It Anyway

August 11, 2022 by Donald Papp 23 Comments

Need to hook a classic Mac mouse up to your modern machine with the help of a DIY USB adapter? [John Floren] has you covered. [John]’s solution uses a board with an ATmega32U4 microcontroller on it to connect to the Mac mouse on one end, and emulate a USB HID (Human Interface Device) on the other. A modern machine therefore recognizes it like it would any other USB input device.

Why is this necessary? The connector on the classic Mac mouse may look like a familiar DE-9 connector, but it is not an RS-232 device and wouldn’t work if it were plugged into a 9-pin serial port. The classic Mac mouse uses a different pinout, and doesn’t have much for brains on the inside. It relies on the host computer to read its encoders and button states directly.

This project is actually a bit of an update to a piece of earlier work [John] did in making a vintage Depraz mouse work with modern systems. He suspected that it wouldn’t take much to have it also work with a classic Mac mouse, and he was right — all it took was updating the pin connections and adding some pull-up resistors. The source code and design files are on GitHub.

Even if one does not particularly want to use a classic Mac mouse for daily work, there’s definitely value in this kind of thing for those who deal in vintage hardware: it allows one to function-check old peripherals without having to fire up a vintage machine.

Continue reading “Want To Use A Classic Mac Mouse On A Modern Computer? No? Here’s How To Do It Anyway” →

Saving Fuel With Advanced Sensors And An Arduino

August 3, 2022 by Ryan Flowers 37 Comments

When [Robot Cantina] isn’t busy tweaking the 420cc Big Block engine in their Honda Insight, they’re probably working on some other completely far out automotive atrocity. In the video below the break, you’ll see them take the concept of a ‘lean burn’ system from the Insight and ~~graft~~ hack it into their 1997 Saturn coupe.

What’s a lean burn system? Simply put, it tricks the car into burning less fuel when it’s cruising under a light load to improve the vehicle’s average mileage. The Saturn’s electronics aren’t sophisticated enough to implement a lean burn system simply, and so [Robot Cantina] did what any of us might have done: hacked it in with an Arduino.

The video does a wonderful job going into the details, but essentially by using an oxygen sensor with finer resolution (wide-band) and then outputting the appropriate narrow band signal to the ECU, [Robot Cantina] can fine tune the air/fuel ratio with nothing more than a potentiometer, and the car’s ECU is none the wiser. What were the results? Well… they weren’t as expected, which means more experimentation, more parts, and hopefully, more videos. We love seeing the scientific method put to fun use!

People are ever in the quest to try interesting new (and sometimes old) ideas, such as this hot rod hacked to run with a lawnmower carburetor.

Continue reading “Saving Fuel With Advanced Sensors And An Arduino” →

A Classic TV Trope For An Escape Room

August 3, 2022 by Sven Gregori 15 Comments

No spooky mansion is complete without a secret passage accessed through a book shelf — or so Hollywood has taught us. What works as a cliché in movies works equally well in an escape room, and whenever there’s escape rooms paired with technology, [Alastair Aitchison] isn’t far. His latest creation: you guessed it, is a secret bookcase door.

For this tutorial, he took a regular book shelf and mounted it onto a wooden door, with the door itself functioning as the shelf’s back panel, and using the door hinges as primary moving mechanism. Knowing how heavy it would become once it’s filled with books, he added some caster wheels hidden in the bottom as support. As for the (un)locking mechanism, [Alastair] did consider a mechanical lock attached on the door’s back side, pulled by a wire attached to a book. But with safety as one of his main concerns, he wanted to keep the risk of anyone getting locked in without an emergency exit at a minimum. A fail-safe magnetic lock hooked up to an Arduino, along with a kill switch served as solution instead.

Since his main target is an escape room, using an Arduino allows also for a whole lot more variety of integrating the secret door into its puzzles, as well as ways to actually unlock it. How about by solving a Rubik’s Cube or with the right touch on a plasma globe?

Continue reading “A Classic TV Trope For An Escape Room” →

A Customizable Macropad To Make Anyone’s Tail Wag

July 28, 2022 by Kristina Panos 4 Comments

[Gili Yankovitch] has always wanted some kind of macro keypad for all those boss-slaying combos he keeps up the sleeve of his wizard robe while playing WoW. Seventeen years later, he finally threw down the gauntlet and built one. But really, this is an understatement, because Paws is kind of the customizable macropad to end all customizable macropads.

This thing is completely bespoke, and yet cookie cutter at the same time — but we mean that in the best possible way. Paws can be made in any shape or form, and quite easily. How is this even possible, you ask? Well, every single key has its own microcontroller.

Yep, each key has an ATtiny85 and a cute little ribbon cable, and these form a token ring network that talks to an Arduino, which provides the keyboard interface to the computer. To make things even easier, [Gili] built a simple programming UI that automatically recognizes the configuration and number of keys, and lets the user choose the most important bit of all — the color of the LED.

[Gili] wanted to combine all the skills he’s learned since the worst timeline started in early 2020 — embedded software, CAD, electronics, and PCB design. We’d like to add networking to that list, especially since he figured out a nice workaround for the slowness of I²C and the limitations of communication between the ‘tiny85s and the Arduino. Though [Gili] may have started out with a tall order, he definitely filled it. Want to get your paws on the design files? Just claw your way over to GitHub.

If your customization interests lie more toward what program is in focus, be sure to check out Keybon, which was one of the many awesome winners of our Odd Inputs and Peculiar Peripherals contest.

A No-Calibration Metal Detector

July 17, 2022 by Jenny List 12 Comments

A traditional early project for someone discovering a love for electronics has been for many years a metal detector. This would mean a few transistors back in the day, but today it’s more likely to involve a microcontroller. [Mircemk] has an example that bends both worlds, with a single transistor oscillator and an Arduino.

This type of metal detector has a large search coil which forms part of the tuned circuit in an oscillator. As a piece of metal enters its range the frequency of oscillation changes. In the old days, this would have been detected as an audible beat frequency with another oscillator. This design would require a calibration step at the start of detecting, to tune the two oscillators to the same frequency.

This detector keeps the first oscillator but eschews the second one in favor of an Arduino. The microcontroller acts as a frequency counter, monitoring the frequency and issuing an alarm when it detects a change likely to be caused by a piece of metal. It may not have some of the finess a human ear could apply to a beat frequency in the all-analogue days, but it’s simple enough to build and it avoids the need for calibration. Seeing it in the video below the break we’re sure that just like those transistor models old, there will be plenty of fun to be had with it.

An Arduino may be one of the current go-to parts, but will it ever displace the 555? Perhaps not in the world of metal detectors!

Continue reading “A No-Calibration Metal Detector” →

A Handy Tester For A Mountain Of PS/2 Keybords

July 12, 2022 by Dan Maloney 16 Comments

The hacking life is not without its challenges, and chief among these is the tendency to always be in acquisition mode. When we come across a great deal on bulk equipment, or see a chance to rescue some obscure gear from the e-waste stream, we generally pounce on it, regardless of the advisability.

We imagine this is why [Nathan] ended up with a hoard of PS/2 keyboards. Seriously, there are like thousands of the things. And rather than lug a computer to them for testing, [Nathan] put together this handy Arduino-based portable tester to see which keyboards still have some life left in them. The video below goes into detail on the build, but the basics are pretty simple — an Arduino, a 16×2 LCD display, and a few bits and bobs to run it off a LiPo pack and charge it up. Plus, of course, a PS/2 jack to plug in a keyboard and power it up. Interestingly, the 16×2 display is an old Parallax unit, from the days when RadioShack still existed and sold their stuff. That required a little effort to get it working with the Arduino, but in the end it works like a charm — plug in a keyboard and whatever you type shows up on the screen.

Of course, it’s hard to look at something like this, and that mountain of keyboards in the background, and not scheme up ways to really automate the whole test process. Perhaps an old 3D printer with a stylus mounted where the hot end would go could press each key in turn while the tester output is recorded — something like this Wordle-bot, but on a keyboard scale. That kind of goes against [Nathan]’s portability goal, but it’s still fun to think about.

Continue reading “A Handy Tester For A Mountain Of PS/2 Keybords” →