Make use of external speed sensors

[Singesang]

Today's portable navigation solutions have an integrated acceleration sensor that make it possible to navigate when there is no gps fix available. This feature is mostly used when the sat fix gets lost (driving through a tunnel e.g.) so that further navigation is still possible (even when it's a bit imprecise)

That speed information can get obtained through a user script that uses OBD/CAN/an acceleration sensor.

[pavelmachek.livejournal.com]

I guess this is better done somewhere else.

Basically you'd want gpsd to use accelerator sensors to compute new positions.

It would be kind of cool, but I'm not sure if those sensors are accurate enough to be useful for more than few seconds.

Anyway, this does not belong to navit.

[KaZeR]

​http://wiki.openmoko.org/wiki/Technical:Accelerometer_Fundamentals, bottom comments, explains why it won't be done in navit in the near future.

[mafketel]

I agree the acceleration sensors have limitations but, there are also gps's with magnetic compass data and if you the add the wheelsensor data of the car. One would be quite accurate. Most cars nowadays have wheelspeedsensors on all wheels thnx to the abs.

Since tires deflate and wear heat up etc, you can calibrate the wheelspeedsensors when there is a good fix. This can also give you a tire deflation warning ;) especially when you also can enter the tire circumference.