Processing power requirements

NETMF & Gadgeteer
1

Hey,

I’ve got a Panda reading a GPS, a RAZOR IMU, and outputting data to an ESC twice a second. I have now realised I will also need it to do a quick distance check every half a second, using the following method:


            int r = 6378100;

            d_lon = dest_lon - lon;
            
            distance = MathEx.Acos(MathEx.Sin(lat)*MathEx.Sin(dest_lat)+MathEx.Cos(lat)*MathEx.Cos(dest_lat)*MathEx.Cos(d_lon))*r;

Is that too much to ask of a Panda? I have absolutely no clue how much processing power trig functions take. There are even simpler alternatives I could fall back to, should I need to.

2

Are you using the GHI math functions? They should be fast

3

Yes I am, and by fast do you mean fast enough? I guess I’m just too used to attempting trig functions on 8bit microprocessors, which never worked too well.

While I’ve got a thread open, I might aswell ask regarding a problem I’m currently having.

I’ve got a class called GPS, where I used to have a constructor with 1 argument. This class is referenced from another project, inside which I am creating a GPS object. This worked well, until I’ve edited the constructor of GPS, made it accept 0 arguments. Clean & built GPS, ensured I have the correct reference about a million times, yet each time I try to build the other project which uses the GPS object, I get a “There is no constructor for GPS which accepts 0 arguments” (or something along those lines).

Any clue hoow to fix this, I’ve spent the last half an hour trying to fix all this, but it is so not working.

4

Maybe you are rebuilding the release of the Gsm and are referencing the debug output in your other project. (Or vica versa)

5

I also onced experienced what Wouter is talking about. This happend to me when i was using VS Express version where you are not able to switch between Debug and Release (i think). Somehow however express managed to compile a release version and reference it. Doing a cleanup didn’t work since only active Debug directory was used.

Create a new solution, add new projects and then copy your code to those projects (using Add Existing in context menu). Then it should work fine.