Strange readings location sensor speed

[craVe_DRIVE]

Hi Team,

I need You help with SPEED parameter of location sensor because I receive stragne ( to low ) readings. I have found some information on forum that I need to x 1.944 the result to receive km/h. BUT final result is still to low according to real car speed ( almost 2 times ).

How to solve this ?

Thank You

Lucas

[SteveJG]

Where did you get the conversion factor of 1.944 Lucas? I think you are converting m/sec to knots, not km/hour.

The 'speed' provided by the LocationSensor is 'average' speed between two successive LocationChanged events. The reported value is not instantaneous speed. Understanding the difference between average and instantaneous may be the reason you do not achieve the results you expect. You need to understand the speed units - the LocationSensor reports speed in m/sec units), convert to km/hr if you want speed in kilometers (1000 meters) and also be aware m/sec must be addressed to convert kilometers/ hour . m/sec * km/1000m * 60 sec/min * 60 min/hour = km/hour .

To convert m/sec to km/hr use this formula:

18 * m/sec / 5 = km/h.

1 meter/second is equal to 3.6 km/h or 1.944 knots .

Does this help Lucas?

Have you read:

A Basic LocationSensor Speedometer

A Basic LocationSensor Speedometer ============================ An app with an analog speedometer display using a GoogleCharts gauge and javascript. This example works on an Android 8.1 and probably all Androids between 5 and at least 8.1 . [speedometer] There are two speedometer dials; 0 to 100 mph and 0 to 50 mph. Modify the html files stored in Media to set different display ranges. ( Make an Analog Gauge and use it to display something useful . shows an Altimeter gauge; you can instea…

How do we measure our speed with location.(speedometer)

Yes, your postulation is basically correct. To record a speed the LocationSensor.LocationChanged must fire at least twice to get a speed rerading. To calculate a speed, the tool must record two separate geolocations. Speed is the rate at which an object’s position changes, measured in meters per second. The equation for speed is simple: distance divided by time.Take the distance traveled (for example the distance from the geolocation of satellite fix #1 to satellite fix #2 . Divide t…

Location Sensor (Speed)

Changing the LocationSensor.Enabled state with a Button is unacceptable? You don’t “want to put a button every time I stop and start again.” Are you afraid of wearing out your finger? There are some alternatives to consider: – unfortunately a Button event handler used like a toggle switch is your best solution to enable and un-enable the LocationChanged event. You could use a Switch component instead but you still would have to engage it. – talk to it; reason with the thing. Use a SpeechR…

If you have not yet read the discussions, they may provide a better understanding of what you are trying to achieve.

Good luck. Just use the correct conversion factor.

[uskiara]

Dear @craVe_DRIVE (Lucas),
I've recently used the LocationSensor to enrich my own Digital Dashboard (AI2 coded) on my car.
The device I'm using is a Lenovo 8" tablet (connected via BT the the EOBD port of my car) fitted with GPS sensor.

I use these blocks to configure the LocationSensor :
in the Screen1_Init procedure I set:
locationsensor Distance = 0 => no minumum distance to fire the event
locationsensor timeInterval = 1000 => 1 second minimum trigger time (comment: it should be according to the theory, but typically it rises far less than 1 second when the GPS has started to fix the points, at least this is the performance on my Lenovo pad)
locationsensor Enabled = True
In the LocationChanged event the following blocks:

As @SteveJG said, please be careful on the conversion factor ! (it must be 3.6 to convert from m/s to Km/h).

As I told, this code is fitted on my pad where I acquire on the vehicle's CAN bus also the speed computed by the Engine Control Unit. The two speeds are fairly comparable, (also with 1 decimal) after the GPS has successufully started to fix the points. As @SteveJG also said, the sensor needs at least two consecutive fixes to compute the speed. This can cause a little discrepancy between the two speeds (GPS vs CAN) in fast accelerations (positive or negative) since the GPS is a bit slower, in these cases, but in "normal" conditions (i.e. if you don't drive "fast and furious" ) the GPS speed is following the "true" one with a good dynamics.
Lastly: when I stop the car (i.e. at the stoplight) the CAN speed goes to 0 immediately, while the GPS's one shows still two decreasing values before getting 0. The opposite when you restart: the GPS speed still shows 0 for a couple of seconds when the CAN speed already shows values greater than 0.
My hint is to don't care about this little and fast disappearing discrepancy and to better keep your attention to the road instead ...
Best wishes !!!