Measuring Car Engine RPM via the Cigarette Lighter


Sometimes we forget how many things we can do with a simple oscilloscope. In this video [Ben] uses one that Tektronix lent him to measure his DeLorean engine RPM. By checking the car main ~12V voltage one may notice that the voltage spikes occurring are directly related to the engine speed, as they are created by the inductive kicks from the ignition coils. Obviously the multiplication you have to do to get the RPMs from the number of spikes per second depends on your engine configuration (flat 4, v6…).

The method that [Ben] used was to search for high amplitude spikes on the (AC coupled) car 12V Fast Fourier Transform (FFT) to get a reliable measurement given the many electrical noise sources present in his car. At the end of his video, he however mentioned that it could still be possible to get a good measurement with a simple voltage comparator and a high enough voltage reference.

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Hackaday Links: January 19, 2014


[Nick] wrote in to tell us about his first blog post. He’s showing off a PWM LED driver he build around a 555 timer. This project uses a lot of basics; some 555 experience, PCB etching, and surface mount soldering. We’d like to know more about the blue substrate on his circuit board!

After seeing the BOM spreadsheet with KiCAD integration a couple of weeks back, [Vassilis] sent in a link to his own Excel-based Bill of Materials helper. We’re wondering if anyone has a similar tool that will work with Open Office?

While we’re on the topic of downloadable documents, here’s a reference PDF for all types of DC measurements. The collection is a free offering from Keithley. [Thanks Buddy]

Since you’re brushing up on your knowledge you may also be interested in a free online microcontroller course offered by UT Austin. They’re targeting the Tiva C Launchpad as the dev board for the class.

This website seems to be a little creepy, but the teardrop shaped 3D printed music box which is being shown off is actually rather neat.

Hackaday Alum [Phil Burgess] threw together a point and shoot camera for Adafruit. It’s a Raspberry Pi, camera board, touchscreen display, and USB battery all rubber banded together. The processing power of the RPi is used to add image processing effects which are shown off in the demo video.

We don’t own a DeLorean. If we did, we’d probably follow the lead of Queen’s University Belfast and turn it into and electric vehicle. [Thanks Jake]

The 3D photocopiers are coming. Here’s a hacked together proof-of-concept from [Marcelo Ruiz]. After laser scanning the part is milled from floral foam.


DeLorean hovercraft

[Matthew Riese] got frustrated waiting for the future to arrive so he could have his flying car. He decided to take things into his own hands and construct the closest thing he could. This turned out to be a hovercraft. Not only that, but he thought that the most fitting shape for this thing would be a DeLorean.  We can’t say that we disagree with him. Unfortunately, there isn’t a whole lot of information on his build. There is this cool video on his kickstarter page (don’t worry, he got funded back in 2010). To make up for the fact that the build information is sparse, we’ve found you some plans to make your own hovercraft. Just add whatever shape body you want, though we have some suggestions.

[via Makezine]

Hackday Links: March 10, 2012

We’re throwing money at our monitor and nothing’s happening!

Sometimes we get hacks sent into our tip line that are outrageously awesome, but apart from a YouTube video we’ve got nothing else to write about. So begins the story of the flying Back to the Future DeLorean quadrocopter. Sadly, the story ends with the video as well. (If you’ve got any info, send it in!)

Fine, we’ll throw in another cool car

Mercedes covered a car with LEDs and made the James Bond’s invisible car from Die Another DayThe Mercedes video cost tens of thousands of dollars to produce, so of course there’s camera trickery; we’re just wondering how much credit Adobe After Effects gets for this build.

Microsoft touchscreen demo might be impossible

Yes, Microsoft does care about user experience. Just take a look at this video from their applied sciences group. They did user testing with touchscreens that updated every 1 millisecond, compared to the ~100ms our phones and tablets usually update. Of course the result was a better UX, but now we’re wondering how they built a touch screen that updates every millisecond? That’s a refresh rate of 1 kHz, and we’ve got no clue how they bodged that one together. We’re probably dealing with a Microsoft Surface projector/IR camera thing here, but that doesn’t answer any questions.

Edit: [Philip Rowney] sent in a tip that it could be this TI touch screen controller that can sample above 1 kHz. The only problem is this chip uses a resistive touch screen, instead of a multitouch-enabled capacitive screen. At least that solves one problem.

And now for something that can measure 1 kHz

[Paleotechnologist] posted an excellent guide to the care and feeding of an oscilloscope. Most of our readers probably already know the ins and outs of their awesome Techtronix and HP units, but that doesn’t mean the younglings won’t have to learn sooner or later.

Good idea, except the part about saving it for spring

In a moment of serendipity, [Valentin] figured out how to use touchscreens with wool gloves. The answer: rub thermal grease into the tip of the index finger. It works, and doesn’t look to be too much of a mess. We’ll remember this for next winter.

The last one didn’t have a picture, so here’s this

[Darrell] used a little bit of LaTeX and Ruby to make colored labels for his resistor collection. We’re struck with the idea of using test tubes to organize resistors. It’s cool and makes everything look all sciencey and stuff.

Is GEK a modern-day Mr. Fusion?

[Nanomonkey] spent the weekend building generators that run off of syngas. All Powers Lab produces Gasifier Experimenter Kits to convert raw material to energy. The kits use Gasification to make a “natural gas like” fuel from materials such as wood chips, walnut shells, construction debris or agricultural waste.

So is this the Mr. Fusion that powered the DeLorean? This Honda fitted with a GEK sure makes it look that way. But all joking aside, this looks like a great way to turn waste in heat or electricity. There’s tons of info on the site to dig through. The controllers are open source which would make it easier to interface with the Google PowerMeter when the system is used as a generator.

eD, the electric DeLorean


Who wouldn’t want a DeLorean, honestly it has to be the one of the coolest cars around, what with its gull wing doors and stainless steel siding. Joking aside [Tom Neiland] and [Dave Delman] went even further, creating eD, the electric DeLorean. It contains around 910 pounds of deep cycle lead batteries, custom transmission adapter plate, and a WarP 9 DC motor controlled by a water cooled 2000 amp Z2K-HV, all together to produce 200 horsepower reaching over 85 miles per hour.

The project cost ended up around $18,000 and they plan to add even more including a digital dash and Lithium batteries to extend the cars travel distance from the currently limited 30-40 miles on a single charge. Unfortunately the two couldn’t get their flux capacitor working, but we feel Dr. Brown would still be proud. Check out a video after the break and the writeup at Jameco.

[Thanks Tech Olive]

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