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+--- Thread: zero timestamps in exported data (/showthread.php?tid=2171)
zero timestamps in exported data - markd - 07-25-2025
Hi,
I did some recording with accelerometer then exported the data, but the first some 1k lines have 'Time (s)' col all zero, though the sensor is yielding data. Tried a few times with same results.
Burst length in pict is some 700ms.
The START system-time in metadata seems consistent with the 1st record rather than with the 1st non-zero-time line, checking with external reference clock (generator sync'd with the phone).
app version is 1.1.16 on Android6.1
any clues?
thanx
RE: zero timestamps in exported data - Jens Noriʇzsɔɥ - 07-28-2025
That's indeed weird and I have no idea what's going on there. AFAIC, the time stamps are now provided by the smartphone firmware, so it's likely a problem that is not in our hand – looks still fixable somehow, though.
Could you please provide some details: is it raw accelerometer data (“with g”) or linear acceleration (“without g”)? Could you copy the first few lines of the “Device Info” (circled “I” in the menu), so without the list of sensors?
RE: zero timestamps in exported data - Jens Noriʇzsɔɥ - 07-28-2025
Hm… looking again at your post: if the START time looks ok and regular data is incoming from 0.027s on at 200 Hertz, then there is a data burst of 1050 values without valid time information that phyphox obtains from Android. Still weird…
RE: zero timestamps in exported data - markd - 07-29-2025
(07-28-2025, 02:25 PM)Jens Noriʇzsɔɥ Wrote: Could you please provide some details: is it raw accelerometer data (“with g”) or linear acceleration (“without g”)? Could you copy the first few lines of the “Device Info” (circled “I” in the menu), so without the list of sensors?
it's acc "with g"
pls see attachment for dev infos (btw it's Android 6.0.1 not 6.1, sorry)
thx
RE: zero timestamps in exported data - Jens Noriʇzsɔɥ - 07-29-2025
Thank you. The S5 mini is not even a rare device. We will look into it with our (that) old Android devices. Unfortunately, Sebastian is on (well earned) annual leave for two more weeks…
Have you tried the new phyphox release 1.2.0? I cannot spot anything in the changelog that looks as it could –even surprisingly– fix this, though.
RE: zero timestamps in exported data - Jens Noriʇzsɔɥ - 07-29-2025
(I wonder if the “burst” is tapping on start, perhaps a bit too early for the start of regular data)
RE: zero timestamps in exported data - markd - 07-30-2025
(07-29-2025, 07:55 PM)Jens Noriʇzsɔɥ Wrote: (I wonder if the “burst” is tapping on start, perhaps a bit too early for the start of regular data)
nope - phone is on top of exciter which is driven with periodic burts, see here the 1st 3 (rows with some signal only)
I'll check|upgrade latest release in case if still compatible once it shows up in f-droid
thx
RE: zero timestamps in exported data - Jens Noriʇzsɔɥ - 07-30-2025
Ah, ok. – This release, phyphox was first available on f-droid (on July 6).
