Hi Ryanne,
At the moment there is no sync method during data Acquisition for Matlab. Technically you should be able to sync the data via post processing. In order to do so you first need to understand how time stamping currently works. Include below is info concerning the time stamp, which can be found from the download section under the file listed as Shimer Packet Format:- It is a 16bit value and will loop around 0 when it exceeds 65536. The time stamp comes from the Shimmer's 32KHz clock and is thus ticking/incrementing 32 times per millisecond. Thus each increment represents 31.25uS of real time. With that in mind in order to sync the data you will first require you to synchronize the internal clock of all Shimmers. In order to do this, place all Shimmers you wish to synchronise into Shimmer Multi Gang Charger and press the reset button on any one of the Shimmers, this will reset all Shimmer internal timestamps at the same time. Once this is done you should now technically be able to sync the data if you keep track of the time differences it takes for each different Shimmer device to start streaming data. Yes bug 0.1.1 is fixed. I would recommend downloading the latest Matlab Instrument Driver. Changes and updates are logged in the Readme file. Best regards, JC _____ From: [email protected] [mailto:[email protected]] On Behalf Of Ryanne Lemmens Sent: 31 October 2012 14:49 To: [email protected] Subject: [Shimmer-users] synchronize shimmer streaming using Matlab Hello, I have a question about streaming multiple shimmers using Matlab. Is it possible to synchronize the shimmers? And how should I do that? I am now using up to 7 shimmers, all 9DOF with accelerometer, gyroscope and magnetometer signals. I've used a matlab function to stream based on the examples in the Matlab instrument driver library (twoshimmerexample.m). When I start streaming multiple shimmer simultaneously, the timestamp is similar but there is a shift in the signals (about 30 secs). I hope someone can help me. Many thanks! And another question, does someone know whether bug 0.1.1 is allready fixed? Kind Regards, Ryanne Dit bericht is uitsluitend bestemd voor de geadresseerde. Het bericht kan vertrouwelijke informatie bevatten. Indien dit bericht niet voor u is bestemd, wordt u vriendelijk verzocht de verzender te informeren en het bericht met eventuele bijlagen te vernietigen. Openbaarmaking, vermenigvuldiging, verspreiding en/of verstrekking van vertrouwelijke informatie aan derden zonder toestemming van de verzender is niet toegestaan.
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