If you look at modern timing system you'll see that the starter's pistol has a switch (or other sensor) that is activated by the trigger/hammer mechanism that fires the blank round.jakwnd wrote: The only real limitation I need from the RTOS is to reliably start the camera recording when the gun fires (GPIO). the rest of the timing can be assured from the elapsed time of the video.
This post has all the info on Machinoid:suicidal_orange wrote: I searched for machinoid to see what it was but got everything from a CNC controller to video games, nothing that looked relevant to your question?
Automatic timing equipment used on swimming events detects competitors with plates (+ backup buttons for judges).jakwnd wrote:Hey all, I am trying to design a FAT (fully automatic timing) system around the RPi and camera module, like the ones used at track and swimming events.
jakwnd wrote:As long as any possible delay is under a hundreth of a second then it can still qualify for the standard.
Thanks for the reply! I read through the NCAA rule book regarding timing. you can download it here [http://www.ncaapublications.com/product ... s/TF14.pdf]FLYFISH TECHNOLOGIES wrote: I have strong doubts that your approach can pass any certificate procedure, but during this development you will gain some new technical knowledge and skills...
Do you think using a reliable RTC could suffice? Heck with the new compute module one could work one into a design.FLYFISH TECHNOLOGIES wrote: Just a small detail: typical certified timekeeping system contains time-base circuit with a heated crystal to maintain very constant temperature -> clock stability.
Ok, you can try...jakwnd wrote:I read through the NCAA rule book regarding timing.
Section 12 is timing, and it seems that It could possibly pass a certificate procedure if any exists.
Define "reliable".jakwnd wrote:Do you think using a reliable RTC could suffice?
I see your point. But I simply cannot seem to find any evidence of a certification or anything of the sort. I'm sure I will have to do extensive tests to ensure the accuracy. Researching all the other systems on the market, I do not see anything related to a 'certification' only a guarantee of accuracy.FLYFISH TECHNOLOGIES wrote: Be aware that there are cases where you'll probably need to prove that the equipment is certified... like best results/records, or when a result causes some bonuses to the competitor (eg. scholarship), etc.
Sports federations/associations don't perform time accuracy/precision/etc. certification tests.jakwnd wrote:But I simply cannot seem to find any evidence of a certification or anything of the sort.
Rather than start the recording when the gun fires and all the possible delays associated with that, why not start the recording before the gun fires and then relate it back via the video to the point of starting?The only real limitation I need from the RTOS is to reliably start the camera recording when the gun fires (GPIO). the rest of the timing can be assured from the elapsed time of the video.
If the aim is to determine the timing from a captured video I wonder if you could even achieve 1/60 second resolution in the timing. With the recent 60/90 fps modes (but more limited resolution) you might be close enough. However you may need to take into account the rolling shutter as part of that. You'd also want to be sure that it's actually capturing at the requested rate rather than say requesting 60fps and actually getting 59fps. This probably wouldn't be visible just by watching the captured video (Film distributors get away with speeding up 24fps Cinematic films to 25fps for the European market - which makes a feature length film a couple of minutes shorter when watched at home!)jakwnd wrote: Section 12 is timing, and it seems that It could possibly pass a certificate procedure if any exists. This is mainly for High School meets. Most High schools don't have a budget for a 2-3 thousand dollar FAT system, so even if this can only qualify for AT (automatic timing - 1/60 of a second) it could still be a good alternative.