Lag

[cleric-k]

Lag

[Cleric-K]

How do you measure the lag?

vjsf should not introduce any feelable lag, since the program loop is quite straightforward - it simply reads the IBUS frames and immediately converts them to vJoy commands.

Also keep in mind that vjsf graphical interface (including the channel monitor) is not reliable for judging latency. The interface updates more rarely than the actual vJoy driver updates. The reason is that the gui of vjsf has only informative role, so trying to update the gui every 7ms (the normal ibus frame rate) will require too much cpu resources and most of the updates wouldn't be even detected by the human eye.

[VIV-IOI]

Thanks, fast feedback!
I simply measure the system lag with a 240fps cam, 60hz monitor, and a real time background ms stopwatch ( a 60hz monitor gives +/- 16ms per frame ).

Nice point, it really makes sense, so gui from vjsf it's not a visual real time feedback that i can use for measuring lag.
Update rate 7ms shows on gui of vjsf is related to input signal on ibus arduino > vjsf output?

For now the best way is try to debug this with real time code latency measure.

Thanks for all info,
Best regards,

[Cleric-K]

The 7ms on vjsf is not latency but the time between the frames (frame rate) - that is how often input ibus frames arrive on the serial port.

In fact, it is not possible to measure latency without additional equipment, because when an ibus frame arrives at the serial port, there's simply no way to tell how long it has been travelling. It could have been sent 1ms ago, or it could have been sent an year ago. The only way is to timestamp the frame as it leaves the transmitter and then track the time when the same frame arrives at the pc. But this is not easy to do, as it would require various tech hacks.

The question is whether you feel lag when you play?
You should check that with different sims.

For example I have suspicion that DRL has some latency on its own. FPV Air seems to be the most responsible. I do fine in sims like FPV Air, Liftoff, but in DRL I find it quite hard to do moves that require more precise timing - like split s-ing into an air gate. This move is quite comfortable in the other sims, but I have no idea why it is so hard for me in DRL. Physics seem to be not that different, so I strongly suspect that (at least on my machine, which is not very gamer-grade at all) DRL simply has some lag which I'm having trouble compensating.
It is interesting that Joshua Bardwell mention exactly the same thing in one of his videos - he said that he kept crashing in DRL and didn't have idea why.
https://www.youtube.com/watch?v=Vbiv3HbymrE&t=16m39s