What’s an OBD-II (typically alternatively known as OBD-2, and different occasions in both type absent the interstitial hyphen) scanner? Answering that query first requires an understanding of what OBD is. The acronym stands for on-board diagnostics; right here’s the introductory abstract from Wikipedia’s entry:
On-board diagnostics (OBD) is a time period referring to a automobile’s self-diagnostic and reporting functionality. OBD methods give the automobile proprietor or restore technician entry to the standing of the assorted automobile sub-systems. The quantity of diagnostic info accessible through OBD has various extensively since its introduction within the early Nineteen Eighties variations of on-board automobile computer systems. Early variations of OBD would merely illuminate a malfunction indicator mild (MIL) or “fool mild” if an issue was detected, however wouldn’t present any info as to the character of the issue. Fashionable OBD implementations use a standardized digital communications port to supply real-time knowledge along with a standardized collection of diagnostic bother codes, or DTCs, which permit an individual to quickly establish and treatment malfunctions inside the automobile.
Apparently, I realized whereas researching this piece, the time period “OBD-I” was retroactively utilized to an earlier California Air Assets Board (CARB)-initiated on-board diagnostics method, after the standardization and rollout of OBD-II roughly a decade later. OBD-I first:
The regulatory intent of OBD-I used to be to encourage auto producers to design dependable emission management methods that stay efficient for the automobile’s “helpful life”. The hope was that by forcing annual emissions testing for California beginning in 1988, and denying registration to autos that didn’t cross, drivers would have a tendency to buy autos that might extra reliably cross the take a look at. OBD-I used to be largely unsuccessful, because the technique of reporting emissions-specific diagnostic info was not standardized. Technical difficulties with acquiring standardized and dependable emissions info from all autos led to an incapacity to implement the annual testing program successfully.
Now for OBD-II, which was necessary for all automobiles bought in america starting in 1996, once more quoting straight from Wikipedia:
OBD-II is an enchancment over OBD-I in each functionality and standardization. The OBD-II normal specifies the kind of diagnostic connector and its pinout, {the electrical} signaling protocols accessible, and the messaging format. It additionally supplies a candidate checklist of car parameters to observe together with methods to encode the info for every. There’s a pin within the connector that gives energy for the scan instrument from the automobile battery, which eliminates the necessity to join a scan instrument to an influence supply individually. Nonetheless, some technicians would possibly nonetheless join the scan instrument to an auxiliary energy supply to guard knowledge within the uncommon occasion {that a} automobile experiences a lack of electrical energy attributable to a malfunction. Lastly, the OBD-II normal supplies an extensible checklist of DTCs. Because of this standardization, a single system can question the on-board laptop(s) in any automobile.
Wikipedia’s total on-board diagnostics entry, which additionally covers a Normal Motors-proprietary diagnostics scheme referred to as Meeting Line Diagnostic Hyperlink (ALDL) together with numerous OBD-II successors, is properly price a learn. And in case you’re not conscious of what the connector is that’s referred to earlier, right here’s a pic:
Again within the non-standardized OBD days, diagnostics connectors weren’t solely applied in numerous shapes, sizes, and pinouts, they have been additionally scattered in numerous areas across the automobile, together with beneath the hood. These days they’re required to be inside 2 ft of the steering wheel; most frequently they’re discovered beneath the dashboard.
One key advantage of such standardization (which, by the way in which, curiously does NOT lengthen to a standard sign protocol in all implementations; 5 choices are supported. Extra on that in a bit…) is that producers can develop knowledge “readers” not just for restore store use but in addition for common automobile proprietor utilization, at minimal so customers can get some concept of the automobile’s standing and, in the event that they’re “wrenches”, also can sort out any needed work themselves. That stated, sort “OBD-II” into the Amazon web site search bar and also you’ll be offered with a prolonged and in any other case bewildering checklist of outcomes spanning a number of pages, for diagnostics scanners ranging in value from lower than $10 to a number of hundred {dollars}. A listing of their variations (albeit off the highest of my head, due to this fact possible not complete) encompasses components reminiscent of:
- How well-known (or not) the gear provider’s “model” is.
- The breadth of autos (each producer, mannequin, and mannequin years) supported.
- If the scanner firmware is usually up to date each to squash bugs and assist new autos, and in that case, how (through USB connection to a pc, Bluetooth obtain from a cell system, direct Wi-Fi obtain, and so on.) and the way usually updates are made accessible.
- If the scanner is solely a diagnostic knowledge reader or if it additionally helps knowledge reset or much more elaborate specific-data configuration programming.
- Which automobile system(s) are supported, and to what diploma in every case: engine, transmission, brakes, steering, charging, and extra basic electrical, and so on.
- Consumer enter schemes: buttons, touchscreen, and so on.
- Information output schemes: LEDs, an LCD show, assist for knowledge add to a linked laptop, smartphone, pill, and so on.
- Connectivity between the male OBD-II connector (and its related circuitry) and the principle reader: wired, Bluetooth, and so on. Some Bluetooth-based items, in truth, supply adequate in-connector “smarts” that the rest of the reader consists solely of software program working on a wirelessly tethered laptop or cell system!
The OBD-II scanner that I presently personal (for causes that I’ll save for an additional weblog submit one other day) is an Autel AutoLink AL519, which I purchased final November from an eBay retailer for $59.98:
I’ve lengthy questioned what its (and comparable merchandise’) insides seemed like. To fulfill my curiosity through this teardown challenge, I went with a extra modestly priced (albeit nonetheless mainstream-featured) system, the THINKOBD 100 from THINKCAR Tech, which set me again solely $14.94 (on sale) from Amazon once I purchased it in January. Right here’s a inventory photograph:
And a promo video:
I’ll as typical start the dissection with a collection of outer packaging photographs:
The THINKOBD 100 is self-powered by the provision voltage (and present) and floor feeds originating on the feminine OBD-II port it’s linked to, which is fairly slick:
I like the brutally trustworthy, albeit grammatically and in any other case considerably convoluted, wording on the bottom:
What’s Cheaper than It isn’t a Good as It, what’s Higher than It isn’t as Low-cost as It
Though THINKCAR TECH is US-based, the THINKOBD 100 is China-manufactured; I’m guessing that imperfect translation to English is on the root of the clumsy wording. In the same vein, I discover it curious that as additionally famous on the bottom, the included person guides present directions in seven totally different languages…none of them Chinese language. Be aware, too, that the effective print signifies that the unit helps all 5 of the aforementioned OBD-II sign protocol choices.
Onward to the remaining (and relatively boring) field sides:
And now, let’s crack open the field’s high flap:
That’s a reassuring sticker!
Right here’s what’s inside, as typical accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for measurement comparability functions.
The THINKOBD 100, not together with its completely linked cable, has dimensions of 4.72 x 2.55 x 0.79 inches, and the assemblage weighs 8 ounces. Be aware, too, the twin person guides; one has three languages’ price of directions, the opposite 4. Listed below are the 2 panels’ price of English-language tutorial prose:
The included (a pleasant contact!) USB cable is used to obtain and set up up to date software program to the system. It’s predictably USB-A on one finish, however archaic mini-USB on the opposite…apparently this product has been accessible on the market for some time.
Right here’s the male OBD-II connector on the finish of the three.2 ft completely hooked up cable:
And right here’s what’s left as soon as the scanner and USB cable are faraway from their white plastic packaging environment:
Now for our affected person. That’s a 1.77 in. (diagonal) 160×128 pixel shade TFT LCD on the entrance:
At backside is the mini-USB connector for updates, together with an information-filled sticker:
The perimeters are pretty bland, though I’ll observe that the textured case is simple to grip:
At high is the different finish of the cable that connects to the OBD-II port:
And eventually, on the again we see the 4 screws that time to our pathway inside:
You understand what comes subsequent, proper?
The PCB pops proper out of the remaining half of the case:
Let’s look first on the comparatively unexciting PCB entrance aspect:
Now for the again aspect, containing the majority of the circuitry:
Right here’s a closeup of the comparatively circuitry-cluttered high half:
On the very high, clearly, is the connector that the OBD-II cable plugs into, with indicators subsequently routing between there and the PCB. Under and to the left of it are two 2903 low-power dual-voltage comparators (producer unknown; does anybody know what firm that vertical-line brand is related to? The second mark line says “AK2SF” if that helps).
Straight beneath the connector is an fascinating chip, the SIT1044T, from an organization referred to as Silicon Web of Issues Expertise. It’s a 5 Mbps high-speed CAN (controller space community) FD (versatile knowledge charge) transceiver; I’m positive that no less than a few of you already additionally seen the related “CANL” and “CANH” markings on the PCB close to the connector, proper? To its proper is the AMS1117, a linear regulator from Superior Monolithic Methods. And to the best of that is one other regulator, the 78M05 (producer unknown).
The biggest (and highest pin depend) IC on the board is the system “brains”, the MM32F103RBT from one other Chinese language semiconductor firm, MindMotion. It’s a 96 MHz Arm Cortex-M3 primarily based SoC additionally containing (amongst different issues) 128 KBytes of flash reminiscence and 20 KBytes of SRAM. And talking of flash reminiscence, beneath the applying processor is extra of it, 64 Mbits of SPI NOR flash reminiscence to be precise, within the chip with markings figuring out it as GigaDevice Semiconductor’s GD25Q64E. No, I don’t know what these blue and inexperienced scribbles on the latter two ICs imply, both, though they have been presumably added by whoever assembled after which examined the PCB containing them!
In spite of everything that upper-half pleasure, the corresponding decrease half of the bottom of the PCB is boring compared, that’s until you’re into diodes and different passives…
At this level I’ll cease disassembling, as a result of as common readers of my teardowns already know, I at all times want to depart my “sufferers” in a situation the place I can later reassemble them to a totally purposeful state for both my or a charity donation recipient’s subsequent use. That stated, I’ll preserve the OBD-II scanner in items till after this text is printed, so I can reply any “what’s that” or different questions you might need. Hold forth within the feedback! And keep tuned for that “why is OBD-II personally related to me” story to comply with sooner-or-later.
—Brian Dipert is the Editor-in-Chief of the Edge AI and Imaginative and prescient Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the corporate’s on-line publication.
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