Hi all,
My son is an up and coming elite sprinter and we’re getting a bit more serious with his training. I want to be able to track at the very least, his instantaneous speeds when training. It would be a bonus to be able to track distance relative to a single point or even just relative to points on the track, ie the start point of a single sprint and perhaps a few points at certain distances, like 2 points 10m apart to measure 10m flying times etc. Absolute position isn’t important, so cm level RTK precision may be over the top if there’s another option to measure position accurately (±100mm would be good enough) relative to a datum. I have thought about a rover/base RTK type setup but it’s getting expensive to the point where I could just buy a commercially available tracking system for not much more. We currently video every session and I analyse the video using a program called Kinovea, which lets me get an idea of speeds but I really want something that tells us immediately what the result was as that works great as a training stimulus and drives him to do better each time.
I am currently using a NEO-M9N board with an ESP32, making a very simple web server that I can view on my phone to see the live speed (sent via ESP NOW). I’m working on adding logging to SD capability as well as looking into javascript to log it onto my laptop when viewing the web page on it. I also have a BNO055 accelerometer breakout board and thought about fusing it with the GPS velocity but I’ve held off that because displacement is probably more important and double integrating acceleration to get distance isn’t a great way to go.
For tracking position I was thinking about having a few ESP32 boards located on the ground and have the wearable ESP32 constantly measuring RSSI (probably BLE as I think it is faster to measure) to detect a crossing event as it passes each one. I figured that even if I’m not getting readings at a high rate I can possibly construct a curve after the crossing event and then interpolate the data to calculate when the crossing event occurred. Not “real” real-time but ~one second latency for that isn’t a big deal, just as long as we get the results of that run before we start the next run. Of course, RTK GPS would take care of this beautifully but I don’t fully understand how I would set it up for something like this and I’m not sure if it’s suitable in a wearable, given the antenna requirements.
OH, BTW, I did try the wireless timing gates (https://learn.sparkfun.com/tutorials/wi … roject/all) and they work great indoors and at the track night under floodlights when there’s no IR bouncing around but if the sun’s up they get false triggers constantly.
Thanks!
Stu.