automotive

64 Articles

Take A Deep Dive Into A Commodity Automotive Radar Chip

January 17, 2023 by 24 Comments

When the automobile industry really began to take off in the 1930s, radar was barely in its infancy, and there was no reason to think something that complicated would ever make its way into the typical car. Yet here we stand less than 100 years later, and radar has been perfected and streamlined so much that an entire radar set can be built on a single chip, and commodity radar modules can be sprinkled all around the average vehicle.

Looking inside these modules is always fascinating, especially when your tour guide is [Shahriar Shahramian] of The Signal Path, as it is for this deep dive into an Infineon 24-GHz automotive radar module. The interesting bit here is the BGT24LTR11 Doppler radar ASIC that Infineon uses in the module, because, well, there’s really not much else on the board. The degree of integration is astonishing here, and [Shahriar]’s walk-through of the datasheet is excellent, as always.

Things get interesting once he gets the module under the microscope and into the X-ray machine, but really interesting once the RF ASIC is uncapped, at the 15:18 mark. The die shots of the silicon germanium chip are impressively clear, and the analysis of all the main circuit blocks — voltage-controlled oscillator, power amps, mixer,  LNAs — is clear and understandable. For our money, though, the best part is the look at the VCO circuit, which appears to use a bank of fuses to tune the tank inductor and keep the radar within a tight 250-Mz bandwidth, for regulatory reasons. We’d love to know more about the process used in the factory to do that bit.

This isn’t [Shahriar]’s first foray into automotive radar, of course — he looked at a 77-GHz FMCW car radar a while back. That one was bizarrely complicated, though, so there’s something more approachable about a commodity product like this.

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Saving Fuel With Advanced Sensors And An Arduino

August 3, 2022 by 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.

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The Surprisingly Manual Process Of Building Automotive Wire Harnesses

July 27, 2022 by 115 Comments

Even from the very earliest days of the automobile age, cars and trucks have been hybrids of mechanical and electrical design. For every piston sliding up and down in a cylinder, there’s a spark plug that needs to be fired at just the right time to make the engine work, and stepping on the brake pedal had better cause the brake lights to come on at the same time hydraulic pressure pinches the wheel rotors between the brake pads.

Without electrical connections, a useful motor vehicle is a practical impossibility. Even long before electricity started becoming the fuel of choice for vehicles, the wires that connect the computers, sensors, actuators, and indicators needed to run a vehicle’s systems were getting more and more complicated by the year. After the engine and the frame, a car’s wiring and electronics are its third most expensive component, and it’s estimated that by 2030, fully half of the average vehicle’s cost will be locked in its electrical system, up from 30% in 2010.

Making sure all those signals get where they’re going, and doing so in a safe and reliable way is the job of a vehicle’s wire harnesses, the bundles of wires that seemingly occupy every possible area of a modern car. The design and manufacturing of wire harnesses is a complex process that relies on specialized software, a degree of automation, and a surprising amount of people-power.

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strut mounted on lathe

Turning Irregular Shapes

July 16, 2022 by 33 Comments

In case you’re not closely following Egyptian Machinist YouTube, you may have missed [Hydraulic House]. It’s gotten even harder to find him since he started posting under[بيت الهيدروليك]. Don’t let the Arabic put you off, he delivers it all in pantomime.

A recent drop is “How To Turn Irregular Shapes On The Lathe“.  We’re not sure, but think the part he’s working on is the front suspension of a  3 wheeled auto-rickshaw. The first metal at the center is over 30cm from the bottom. No problem, he just makes a long driven dead center from a bit of scrap material and goes on with his business.

By no means is this the only cool video.  We liked his video on a remote pumped hydraulic jack  and one on making your own hydraulic valves.

If you’re into machinist-y things, don’t miss him. Every video is full of pretty nifty tricks, sometimes made with a zany disregard of some basics like “maybe better to have done the welding before mounting in the lathe”, turning with a cutoff tool (I think), and occasionally letting go of the chuck key. It’s definitely ‘oh, get on with it’ machine shop work.

We love videos from professionals in the developing world making with relatively simple tools. Often hobby hackers are in the same position, milling with a lathe and some patience instead of a giant Okuma. Not long ago we posted this article about making helical parts , with the same ‘imagination and skill beats more machinery any day’ vibe.

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Car Hacker Hacks Lawn Care Carb Into Hot Rod Car

April 21, 2022 by 45 Comments

Internal combustion engines have often been described (quite correctly) as air pumps, and because of this nature, they tend to respond very well to more air. Why? Because more air means more fuel, and more fuel means more power- the very nature of hot rodding itself. [Thunderhead289] is an accomplished car hacker, and he’s decided to take things the opposite direction: Less air, less fuel… more mileage? As you can see in the video below the break, [Thunderhead289] has figured out how to mount a single barrel carburetor from a lawn mower to the four barrel intake of a Ford 302– a V8 engine that’s many times larger than the largest single cylinder lawnmower!

The hacks start not just with the concept, but with getting the carburetor installed. Rather than being a downdraft carburetor, the new unit is a side draft, with the float bowl below the carb’s venturi. To mount it, a 3d printed adapter was made, which was no small feat on its own. [Thunderhead289] had to get quite creative and even elevate the temperature of his workshop to over 100 degrees Fahrenheit (38 Celsius) to get the print finished properly. Even then, the 34 hour print damaged his Ender printer, but not before completing the part.

The hackery doesn’t stop there, because simply mounting the carburetor is only half the battle. Getting the engine to run properly with such a huge intake restriction is a new task all its own, with a deeper dive into fuel pressure management, proper distributor timing, and instrumenting the car to make sure it won’t self destruct due to a poor fuel mixture.

While [Thunderhead289] hasn’t been able to check the mileage of his vehicle yet, just getting it running smoothly is quite an accomplishment. If silly car hacks are your thing, check out [Robot Cantina]’s 212cc powered Insight and how they checked the output of their little engine. Thanks to [plainspicker] for the tip!

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3D Printing Concept Car (Parts)

March 23, 2022 by 6 Comments

When you want to fabricate something you either start with something and take away what you don’t want — subtractive manufacturing — or you start with nothing and add material, which is additive manufacturing that we usually call 3D printing. Popular Science recently took a look inside Vital Auto, the British lab that uses 3D printing for high-end concept cars from companies like Rolls-Royce, McLauren, Jaguar, and others. In the video below, [Anthony Barnicott], an engineer for Vital, says that the two technologies — additive and subtractive — work best when used together.

As you might expect, they are not using a $200 FDM printer. They have three Formlabs 3Ls that print with resin and five Formlab Fuse 1 selective laser sintering printers. While metal printers are still uncommon in hacker’s workshops, resin printers are now very affordable although your garage printer is probably a good bit smaller than the 3L’s 335x200x300 mm volume. For comparison, an LCD-based AnyCubic Photon X provides just 165x132x80 mm. Of course, you’re looking at about $11,000 for the dual-laser 3L versus about $240 for the Photon.

Vital started building the EP9 electric car concept for NIO, an electric car maker in China. You can imagine that modern manufacturing machines make it possible to create more sophisticated concept cars faster. How many times do you want to tweak a part that takes a machinist eight hours to produce? But if you can just let a machine run overnight and get the result in the morning, you are more likely to change and refine the part.

Vital Auto is an interesting look at how professional fabrication shops are using the same technologies we do, at least at the core. We’ve noted before how these same technologies are making homebrew projects look better than some commercial products not long ago. You can print big things if you break them up, of course. Or, break the bank and buy a really big printer.

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Kia Recalls Cars Over Airbag Controller Assembly Issue

March 9, 2022 by 26 Comments

Last month Kia Motors announced a large recall due to possibly defective airbag controller units (ACU). The recall spans many models and model years — in the United States alone it covers over 400K cars, and over half a million cars worldwide. From the NHTSA report we learn that the problem happened at assembly when the cover of some ACUs interfered with the pins of an EEPROM chip. This can cause some of the pins to open-circuit. If your car had this problem, a warning light would come on, but more seriously, the airbags would not deploy in an accident. Kia estimates that less than 1% of the cars using this ACU have this issue. Cars which have this fault will get a new ACU, and other cars will get a firmware upgrade to keep this from happening should the EEPROM pins break loose in the future.

We think this EEPROM is used for logging errors and crash events, and is therefore not in the critical path for airbag deployment. The original firmware apparently prevented deployment if the EEPROM had a fault. Presumably, after this patch, if pins break in the future, the fault indicator still lights up but you’ll have functioning airbags.

It’s not clear if these broken EEPROM pin solder joints were present from the start and the factory test procedures didn’t catch the problem. Or did the pins left the factory intact and were subsequently broke due to bumps and vibrations. Hardware issues aside, having safety critical firmware perform its primary function even when faults exist in non-essential parts of the circuit seems like a requirement that should have been applied to the ACU from the beginning.

This is a reminder of the importance of enclosure design and making sure your PCB layouts take into account all clearances necessary for the entire assembly. How many times have you got your PCB back and realized you forgot to even put mounting holes?

We covered a similar issue a couple of years ago regarding the Takata airbag fiasco. If you have a Kia, this form on their website tells you whether your vehicle is subject to the recall or not.