Hi,
I've exported my daily activity of December 22, 2016 from the Garmin Connect site and trying to extract my heart rate values. I'm calculating the timestamp of the heart rate based on this post
https://www.thisisant.com/forum/viewthread/6374/ but the date seems to be off.
Based on the Garmin Connect site, there was only one time where I had a harte rate of 111, which is at 1:40pm (13:40 CET) as seen in attachment
hearrate_1340_111.png. The FIT files also provide only one heart rate value with 111, but with a completely different timestamp:
Monitoring:
Heart Rate: 111
Time Stamp 16: 64080
Calculated Timestamp: Thu Dec 22 22:32:00 CET 2016
Looking back at the Garmin Connect site again, I had a heart rate of 106 at this timestamp (attachment
hearrate_2232_106.png).
My procedure for calculating the timestamp is as follows:
I have a member variable where the timestamp of the monitoring message will be set
monitoringMesgTimeStamp = mesg.getTimestamp().getTimestamp();
when the message contains a heart rate, the timestamp will be calculated
if( mesg.getHeartRate() != null) {
System.out.print( " Heart Rate: " );
System.out.println( mesg.getHeartRate() );
System.out.print( " Time Stamp 16: " );
System.out.println( mesg.getTimestamp16() );
Long heartRateTimeStamp = monitoringMesgTimeStamp + (( mesg.getTimestamp16() - ( monitoringMesgTimeStamp & 0xFFFF ) ) & 0xFFFF);
System.out.println( " Calculated Timestamp: " + new DateTime(heartRateTimeStamp));
}
Is there something wrong with the way I'm calculating the values or does the Garmin Connect exported files are corrupt? Sadly, I could not attach the exported ZIP file to this post, but if required for further support, let me know.
Environment: Windows 10, Java 8 Update 73, IntelliJ 15.04
Thanks,
Patrick
UPDATE 1:
I've extracted the the whole day as csv file and created a diagram. The diagram generated in Excel looks similar to the one shown in Garmin Connect. The Excel version is more detailed as the FIT files provide the hear rate per minute while Garmin Connect shows the heart rate in a two minute interval, but every value seems to be off by 2 - 6 beats, as shown in attachment
hearrate_diff.png. This raises the question whether Garmin Connect has problems in displaying the heart rate correctly or is there a problem with the export?
