This forum uses cookies
This forum makes use of cookies to store your login information if you are registered, and your last visit if you are not. Cookies are small text documents stored on your computer; the cookies set by this forum can only be used on this website and pose no security risk. Cookies on this forum also track the specific topics you have read and when you last read them. Please confirm whether you accept or reject these cookies being set.

A cookie will be stored in your browser regardless of choice to prevent you being asked this question again. You will be able to change your cookie settings at any time using the link in the footer.

large skips in time stamps
#1
Hello I tried searching but didn't come up with much. Apologies if this is a well-known aspect of phyphox. 

I found this thread:
https://phyphox.org/forums/showthread.ph...large+data

But not sure if my issue is related. My issue: without thinking much about sample rate, I hopped on a roller coaster and started the accelerometer (iPhone 10,3). These rides are short, maybe 6-7 min at a time, but since I keep the phone secure in a pocket, I have to start the data-logging relatively far in advance before the ride starts (a minute?). At the end of the ride, the phone is inaccessible in my pocket until I can get out of the ride, but generally less than a minute, and still taking data. I export as csv and at first glance the data looks good, very fine grained of course, but in detail there are sudden gaps in the data. Example: 

Data file with 5741 data points. There is a sudden jump in the timestamps from 62.69 to 305.21, then one at 316.29 to 459.62, and a final jump from 468.50 to 632.18. The data ends at 632.27. The meta time file shows START at 0.00, PAUSE at 3.66, START at 3.66, and PAUSE at 632.29. Screenshot shows a basic plot of data highlighting the gaps (I got a warning about multiple screenshots but there should be only one).

I'm having a hard time figuring out what's going on. It's as if the sensors' algorithm decide to suppress data collection for periods of time. I realize that phyphox is limited by how and when the sensors choose to provide data. Am I trying to take too much data or for too long? Is this an issue on the data export end? If there an obvious piece of documentation I'm missing?


Attached Files Thumbnail(s)
   
Reply


Messages In This Thread
large skips in time stamps - by jeglin - 08-27-2022, 05:20 PM
RE: large skips in time stamps - by jeglin - 08-30-2022, 04:34 AM
RE: large skips in time stamps - by jeglin - 08-30-2022, 04:58 PM
RE: large skips in time stamps - by jeglin - 09-05-2022, 06:39 PM

Forum Jump: