Delay between the start of activity and the start of sensors

[jjpaz]

Hi

Since 2.20.30 software version it was included the “no delay” between the start of activity and the start of the timer in the watch. Until that version the timer and activity screen started 5-6 seconds after pushing start button.
Well, in my S9P I’m watching this behavior reviewing activities in SuuntoApp:

• I push start button
• Watch starts timer. During first 10 seconds the timer freezes two times during 2-3 seconds.
• 5 seconds after start, watch starts to record position (starts GPS tracking, position in the map is not the position in wich I pushed start button)
• 8-10 seconds after start, watch starts to show heartrate.
• 13-14 seconds after start, watch starts to save altitude and speed.

So it seems that, altougth the timer is running, the watch needs at least 10 seconds to start all sensors and start recording activity, is this OK?
It works similar way in my S9B so it seems that software is running that way.

You can review your own activities in SuuntoApp (advisable to use zoom):

Beggining of activity (30m of distance?):

After 14seconds (altitude and speed didn’t change):

[Egika]

@jjpaz just adding some guessing here:
Some of those values need to be low pass filtered. Otherwise you would see just jittering and noisy signals.
Depending on the time constant of those low pass filters, data will be ready to be displayed after a few seconds.
Not sure if this explains everything you have been observing.

[jjpaz]

@Egika Thanks for your reply. That’s a good explanation, my post is only to ask if that’s a regular behaviour.
I understand that it’s OK and is the correct behaviour at the start of the activity but it’s a bit surprising

[dombo]

@Egika hm, as I have pre-start screen, with shown heart rate, sensors connected and GPS fixed, I don’t see any need and reason to low-pass filter of these data on the beginning of the activity itself.

[jjpaz]

I’ve been reviewing old activities (february 2022) and the behavior is the same, delay 10seconds after pushing start button. Perhaps now is 2-3 seconds slower

[zhang965]

S9pp here, my watch doesn’t freeze in the beginning but the activity graph, it begins in 30m

[zhang965]

@Egika said in Delay between the start of activity and the start of sensors:

@jjpaz just adding some guessing here:
Some of those values need to be low pass filtered. Otherwise you would see just jittering and noisy signals.
Depending on the time constant of those low pass filters, data will be ready to be displayed after a few seconds.
Not sure if this explains everything you have been observing.

Not for my case, I begin running 5s before hitting the button, so my speed should not be low enough to be filtered

[Mario Malčak]

@jjpaz Hi, I noticed the samo after the last update. I connected it with watch restarting in activity (there is another whole topic about it in this forum). I’ve noticed that if I start running immediately after hitting start before it reeds all the sensors that my watch restarts. If I wait for 20-30 seconds than it doesn’t restart.
Anyhow it’s all so annoying after this software update. I never know will my S9B work or not when I go running

[jjpaz]

@zhang965 Same behavior, so this is the standard working mechanism for starting activities in Suunto watches.
I don’t know how it works in other brands, it’s just my own curiosity.

[Dimitrios Kanellopoulos]

this behviour was there since 2016 afaik (Spartans). We have a starting filter to remove any anomalies from starting without speed (difficult gps situation)

[jjpaz]

@Dimitrios-Kanellopoulos Thanks! Curiosity satisfied!

[Egika]

@zhang965 said in Delay between the start of activity and the start of sensors:

@Egika said in Delay between the start of activity and the start of sensors:

@jjpaz just adding some guessing here:
Some of those values need to be low pass filtered. Otherwise you would see just jittering and noisy signals.
Depending on the time constant of those low pass filters, data will be ready to be displayed after a few seconds.
Not sure if this explains everything you have been observing.

Not for my case, I begin running 5s before hitting the button, so my speed should not be low enough to be filtered

By filtering, I don’t mean to discard data that is below or above a certain threshold.
A low pass filter basically needs to smaple data for a certain time before yielding output data.

[dombo]

@Dimitrios-Kanellopoulos why you don’t use starting filter from the data from pre-start screen, where sensors are connected and gps fixed? by hitting start it means to start. not to start to prepare for start. I also don’t like this, as for races it is useless.

[Dimitrios Kanellopoulos]

There is room for improvement that is true. I hear you