Automotive diagnostics have come a long way since the “idiot lights” of the 1980s. The current version of the on-board diagnostics (OBD) protocol provides real time data as well as fault diagnostics, thanks to the numerous sensors connected to the data network in the modern vehicle. While the hardware interface is fairly standardized now, manufacturers use one of several different standards to encode the data. [Alex Sidorenko] has built an open source OBD-II Adapter which provides a serial interface using the ELM327 command set and supports all OBD-II standards.
The hardware is built around the LPC1517 Cortex-M3 microprocessor and can accept a couple of different versions. Here’s the PDF schematic, and a set of Gerber files (ZIP archive) for the PCB layout, if you’d like to dig in to it’s internals. The MC33660 ISO K Line Serial Link Interface device is used to provide bi-directional half-duplex communication interface with the micro-controller. Also included is the TJF1051, a high-speed CAN transceiver that provides an interface between the micro controller and the physical two-wire CAN lines on the ODB-II connector. The serial output from the adapter board is connected to a computer using a serial to USB adapter.
The software is written in C++ for the LPCXpresso IDE – a GNU tool chain for ARM Cortex-M processors, but can also be compiled using a couple of other toolchains. He’s got instructions if you’d like to build the firmware from source, or if you’d like to program the adapter via Flash Magic.
We featured [Alex]’s inexpensive PIC based ODB-II interface way back in 2007, so he’s been working on this for a while and has a good grip on what he’s doing.
[Bruce Land] sent in this cool final project for ECE 4760 at Cornell University. Dubbed TrckrX, it is an OBD-II tracking and data logging system built into a BMW E36 M3. The car in question is being used in some auotocross competitions. The driver wanted instant access to some data as well as a log of everything for later analysis. The unit gives a real time display of vehicle speed, coolant temp, and RPM. G-force and timestamps are stored on the SD card.
We think this is a very cool idea, and could be quite useful in some instances. The real time display of speed and RPM seem a bit peculiar as the car’s speedometer and tachometer are more appropriately placed for real time information. However, we completely understand that this was a class project and this person may not have wanted to replace their dash cluster with a new readout.
[Steve] let us know about his MultiDisplay car monitoring system. Unlike traditional systems that rely on interfacing with the OBD-II protocol and existing car computer, the MultiDisplay uses an Arduino and custom shield with a combination of sensors; including temperatures, pressures, throttle, Boost, and etc. The data collected can then be displayed on a 20×4 LCD or streamed to a PC with visualization and event recording.
It’s nice to see half a years worth of work finally be complete and presented in such a clean and professional manner, keep up the good work [Steve]
[Avi Aisenberg] sent us his final project for ece 4760. His team built and OBD-II data interface. Even though OBD-II is an industry standard, each manufacturer has implemented it differently. This is where this project shines. They have built it to be capable of talking to any of them. Not only that, but it has a nice backlit LCD screen for diagnosing issues without having to go back to your computer and downloading the data. If you really don’t need all the bells and whistles, you can make one for roughly $15. They even have an OBD-II app for the iPhone.
Rev by DevToaster is an application for the iPhone and iPod Touch that allows real-time monitoring of vehicle ECU data from the OBD-II port. Rev interfaces with a WiFi OBD-II dongle.
If your check engine light is on or flashing, REV is able to check the engine code, list all of the engine codes stored in the vehicle, and reset the stored codes or check engine light.
Rev is able to monitor real-time; vehicle speed, RPM, fuel consumption, engine coolant temp, fuel pressure, calculated engine load, throttle position, intake manifold pressure, air intake temp, timing advance, mass air flow, fuel level, barometric pressure, EVAP system vapor pressure, and fuel trim.
A brief video of REV in action is after the break.
Continue reading “iPhone OBD-II app”
In the past few years, we’ve seen a growth in car hacking. Newer tools are being released, which makes it faster and cheaper to get into automotive tinkering. Today we’re taking a first look at the M2, a new device from the folks at Macchina.
The Macchina M1 was the first release of a hacker friendly automotive device from the company. This was an Arduino compatible board, which kept the Arduino form factor but added interface hardware for the protocols most commonly found in cars. This allowed for anyone familiar with Arduino to start tinkering with cars in a familiar fashion. The form factor was convenient for adding standard shields, but was a bit large for using as a device connected to the industry standard OBD-II connector under the dash.
The Macchina M2 is a redesign that crams the M1’s feature set into a smaller form factor, modularizes the design, and adds some new features. With their Kickstarter launching today, they sent us a developer kit to review. Here’s our first look at the device.
Continue reading “First Look: Macchina M2”
The 90s were a pivotal time in world history, and 1996 was no different. You might have spent the year glued to the TV playing Super Mario 64, or perhaps you were busy campaigning for Bill Clinton or Bob Dole, or maybe you were so depressed that Princess Diana and Prince Charles divorced that you spent the whole year locked in your room, a prisoner of your own existential nihilism. Whatever you did, though, it’s likely that one major event passed you by without a thought: The standardization of on-board vehicle diagnostics (in the US), otherwise known as OBD-II.
In the 1970s, vehicles (in some western countries, at least) were subject to ever-increasing restrictions on emissions. Most companies began switching from carburetors to efficient fuel injection systems, but even that wouldn’t be enough for the new standards. Cars began to carry rudimentary computer systems to manage and control the influx of valves, meters, and sensors that became the new norm. And, as one would guess, every car company had their own standard for managing and monitoring these computer systems. Eventually they would settle on the OBD system that we have today.
Continue reading “Maintenance, Emissions, and Privacy: The OBD Story”