Distance anxiety

I've done more than 100 miles on my electric longboard now and the experience has been great. My travel distance on the skateboard for my commute to work is 2.5 miles each way. Sometimes longer when the weather is really hot and I choose a really picturesque path through the civic park.

I've tried the trip going many different ways and have learned which paths are the smoothest:- It's surprising how some tarmacked roads, although looking fairly smooth in appearance, give more judder than others.

Despite, knowing the board can do 4+ miles before needing a recharge, I was topping up the board battery power in the evening before work and during work. I never had a feel as to when the batteries would run out, as I wasn't monitoring my total distance for work or for play.

I've got into a regular pattern now with skateboarding to and from work. So now I only charge the board up at work :) However,  I do travel into the city centre on the board occasionally (just over 2 miles). One day on the way back I ran out of power. The board bleeped and then a two minutes later the power stopped!  I'm sure that beep should have given me more notice than that! - something I will have to monitor in future use. I was about a mile from home and had to lug that board all the way back. I did try free wheeling but fast concluded I needed more practice.

So I've been thinking about mounting a device on the skateboard to measure distance travelled. Knowing about the distance covered after each charge I can better forecast when the board needs a recharge.  Sure I could use an app on a smart phone to measure distance, but why not treat the board like a car  and have a permanent record associated to the vehicle.

A quick Google on the internet and a few attempts are evident. One manufacturer of conventional Skateboard use to make a board with built in odometer. Also a couple of hackers have made odometers for their boards. There's a nice "how to" on the instructables website. It uses the ubiquitous Arduino microprocessor, a magnet embedded on one of the skateboard wheels and a magnetic reed relay switch mounted close to the wheel on the skateboard truck. The Arduino microprocessor counts every time the magnet passes the reed relay  switch. Each pass of the magnet represents one revolution. Knowing the wheel diameter, the number of revolutions can be converted to distance. This is exactly how many commercial cycle odometer/computers work. I'd rather use something of the shelf than build from scratch myself. So I am currently investigating if a cycle computer could be re-purposed for measuring distance and speed on my longboard.