Best way to measure distance?

Projects General Guidance
1

Hey all,

I want to make a system that tracks how far I go on a longboard (the device will be attached somehow).

What is the best approach to this? I have seen both GPS and wheel rotation counters brought up, but the rotation counter seems like it might be too bulky (the longboard is quite low to the ground). Would a GPS be the best approach here or would I encounter significant stacking errors as I measure longer distances?

Thanks.

3

Ah, longboard as in a skateboard that is longer. I'd be measuring miles.

5

wouldn't take much to mount a magnet on an axle, and a mag sensor on the axle frame, then count pulses on a Teensy, as an example. Do you need a display 'while rolling', or can you settle for reading out the count later?

6

Better yet, let Mom do the math, just enable tracking!

7

It would be nice to have a display with distance/current speed.

8

Where would you mount that?

9

Probably on top of the very front of the board - tbh I'm not entirely sure how much of this is feasible/practical, just trying to get ideas and learn.

10

feasible, yes, practical - well, it's going to take a beating on a skateboard, right? If 'short lifetime' is okay, or you won't be putting it through torture, then yes, it can be done.
Points to ponder -

  • must be visible/readable in daylight, right? So large print/large display, unless you're shorter than most
  • must be powered for long runtimes, right? So power consumption of the display is a factor
  • Powered by what - batteries mounted on the board, so size/weight/mounting location are all factors

The sensor is really the tip of the iceberg, I think. Give us some replies for the above, and we'll give you more to chew on.

11

I think it shouldn't take too much of a beating - longboards (at least in this case) are pretty much just used to get from point A to B, not really the abuse that a normal skateboard would go through.

And yeah, battery concern is something to consider. I would use a phone to do this, but I don't want to have to map out where I went/calculate every time I ride - the Arduino draws me since I can just turn it on and begin tracking.

Thanks for the help, I think I'll sit on it and see if its worth the hassle.

13

Good point. I could always just make something small and maybe stick it in my bag/pocket using GPS, but I imagine size/accuracy might be an issue.

15

I've done this with GPS. About 500' error over a 15 mile distance. Most accurate approach I found was to log position every 10 seconds and calculate distance between those positions and accumulate. That was at highway speeds; perhaps only log every minute since you're travelling slower.

16

The last thing I would ever do while riding is look at my feet. "Look there, go there."