Recently a new energy meter was installed in my home. The new meter is a so called Dutch Smart Meter which means as much as that it is
a digital meter instead of the good old Ferraris meter, it will send its usage data to the network operator via GPRS and has a “P1” port which is just a regular RJ11/RJ12 socket over which it transmits using the DSMR protocol (v4.
One of my projects is building my own timing system for speed skating. I have some ideas of how to build this, but to be sure of the feasibility and needed components I decided to ask some help on reddit/arduino. It is a good description of the project too:
In ice skating and speed skating they employ Photoelectric Retroreflective Sensors (lasers) to time passing over the start/finish line. As a hobbyist ice/speed skater I want to build such a system so we can organise competitions with our club, and time results precisely.
Normally as a programmer Float’s are more than precise enough. During one of my projects however I had some serious headaches because of it. At start of the project I was rolling my own points in 3D-space, just a fancy wrapper around 3 Doubles. When I needed more vector powers (cross products, quaternations, rotation matrices) I switched to com.github.jpbetz.subspace.Vector3 from https://github.com/jpbetz/subspace. This Vector3 uses 3 Floats internally, which was fine, cause it wouldn’t make that much of a difference, I thought.
Inline skating is one of my favourite things to do during summer, and I love to explore new routes. With skates however the road quality is very important. If the asphalt has too much gravel the skates shake heavily and the experience is awful.
Strava, logging activities for cycling and running has had Heatmaps for quite some time. Also their Route Planner integrates the same data and uses *popularity* to snap routes to frequently traveled roads.