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.