FAQ
What is OBD?
Do I need an OBD-II compatible car to use Carman?
Does my car have OBD-II?
Do I need any special hardware to connect Carman to a car?
Which car models Carman support?
Why there are two applications in Carman package?
When I run the Rich view I've got a message saying that I must configure the application on the other view. What should I do?
Why does it take so long to get response for each sensor?
Why Carman does not update all sensors values in a screen at once?
Why some of the gauges seems not to be receiving any value?
Why I'm not able to use the Rich view if the Carman Hildon based view is running?
When installing python 2.5, the Application Manager returns an error. What should I do?
How can I contribute to Carman project?
What is OBD?
OBD, or On Board Diagnostics, is a system used on automobiles to monitor some components and to detect malfunction. If some component is not functioning properly, information about the system is stored in an on-board computer so it can be recovered later by the service technician. OBD-II is the second and the most current version of this technology.
Do I need an OBD-II compatible car to use Carman?
Yes, you need ODB-II compatible car to use Carman. But you may use or try Carman in simulator mode also to see how it works.
Does my car have OBD-II?
If your car model year is 1996 or above, it is most likely to be OBD-II compliant. In doubt, ask your car manufacturer.
Do I need any special hardware to connect Carman to a car?
Yes, the OBD-II plug in the Car is not compatible to any computer connector. So, you must use a "Scan Tool" to convert the signal to a Serial or USB connector (or directly to Bluetooth). Right now, Carman only supports ElmScan 5 Scan tool, though it can be easily extended to support others in the future.
The connection between the Scan Tool and the N800 (or 770) is done using Bluetooth. So you must use a Scan tool that already support Bluetooth (e.g. Car-Pal and OBDKey) or you must have a Serial to Bluetooth adapter that supports the serial port profile (SPP). We've only tested Carman with the Firefly serial adapter, but any adapter that supports SSP should work.
Which car models Carman support?
At the moment Carman has only been tested with Brazilian cars, and only with the standard OBD-II PIDS. We are working in a new feature called car "profile" that will allow further customization to be done in Carman so it can handle better the different car Models. But, as we do not have any access to most available cars, we will need the community help to provide information on that. Please see the question "How can I contribute to Carman project?"
Why there are two applications in Carman package?
The Carman program is composed of two views: a Hildon based view and a Pygame based (Rich) view. The Hildon based view provides more information and was designed to be used in situation that requires more user interaction (like changing user configuration). On other hand, the Pygame based view was designed to be really fancy and requires low user interaction.
When I run the Rich view I got a message saying that I must configure the application on the other view. What should I do?
As the Pygame Rich view as designed to have low user interaction, all the configuration needs to be done on the Hildon based view. This error usually happens when you run the Rich view first without configuring the connection on the Hildon.
Why does it take so long to get response for each sensor?
How long it takes to get an information from the car electronic control unit depends on each car model. Usually this time should be around half a second. If it is taking much longer than this, probably the connection should be investigated.
Why Carman does not update all sensors values in a screen at once?
Once connected, the Carman will gather information for each sensor from ElmScan in a serial way, that is, one after another.
Why some of the gauges seems not to be receiving any value?
Carman uses the sensor PID to request the sensor data. The generic profile uses the standard PIDs from the OBD-II standard. The problem is that some manufacturers changes the PID "meaning" or use hidden PIDs. In that case, Carman will simply ignore the data received.
Why I'm not able to use the Rich view if the Carman Hildon based view is running?
In 770, you will need 16MB of virtual memory to run both applications.
When installing python 2.5, the Application Manager returns an error. What should I do?
Please be sure that you have followed all the instructions on our Download page. One usual source of problem is the use of wrong repositories in Application Catalog. If you are installing on 770, be sure to use the Gregale repository. If you are installing on N800, be sure to use the Bora repository.
How can I contribute to Carman project?
Carman is an Open Source project. You can contribute with Carman in a number of ways:
