Native Development

[lyon819]

Does anyone know how to get previous data point?

For java, last point = current point and put the line after current point.

However, I don't know how to get the previous data point from C programming.

Thank your help.

[gbeukeboom]

Could you clarify what you mean by "previous data point"? Are you trying to retrieve the previous acceleration/location etc of the device?

[lyon819]

I tried to get the previous acceleration.

The code is at below. I tried to use buffer to get the previous acceleration. I don't know what's wrong.

The code didn't work.

if(paused==2){
                            for (i =0; i < 2; i++){
                                sensor_event_get_xyz(event, &force_x[i], &force_y[i], &force_z[i]);
                                if(force_x[0] != force_x[1]){
                                    ftime(&tmb[i]);
                                    fprintf(f,"%ld%d, %7.3f, %7.3f, %7.3f\n", tmb[i].time, tmb[i].millitm, force_x[i], force_y[i], force_z[i]);
                                }
                            }
                        }

[gbeukeboom]

Is the application listening for sensor events? Are you trying to get events as they come in or retrieve previous sensor events from the buffer?

[lyon819]

Yes, I tried to listen sensor event, and then put data into a buffer in order to get the previous data point.

Or,

If you know other way to get the previous data point.

Could you share the information.

Thank you,

[gbeukeboom]

Could you follow the guide here:

https://bdsc.webapps.blackberry.com/native/beta/documentation/recipe_accelerometer_1935321_11.html

Also the Falling Blocks sample shows how to read acceleration as well:

https://bdsc.webapps.blackberry.com/native/beta/sampleapps

You can read all sensor events as they occur, but *not* retrieve previous values. If previous data is needed, could you explain how it would be useful.

[lyon819]

I can get acceleration.

But, I tried to get the previous data point, which can be calculated with the current data point.

For example:

X = Current acceleration - the previous acceleration.

or

X = Current acceleration - the previous two acceleration.

[gbeukeboom]

You will need to track this yourself.

[lyon819]

Do you know what's wrong in my code?

Thank you,

[gbeukeboom]

Could you explain what your code is trying to achieve and what the results actually are vs what is expected?