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ryohajika / ShimmerProjectECL

ShimmerProjectECL is a java-based project to make a simple software to stream data from a Shimmer sensor using LSL(LabStreamingLayer) protocol. Designed for the Windows platform and Shimmer GSR+ sensor.
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shimmer latency #1

Open pmavros opened 1 year ago

pmavros commented 1 year ago

Hi Ryo ,

Thanks for writing this application it could be very useful for our study. I have one question: do you record or assess the latency betweeen when a signal is measured on the shimmer and when it is received on the computer (I know LSL takes care of the latencies further downstream, between ECL and LabRecorder for instance).

Many thanks, Panos

ryohajika commented 1 year ago

Hi Panos, there is no method implemented to see the latency between the client computer and a shimmer sensor. However, Shimmer sensor has its own timestamp which is apart from the client's timestamp, and I would try one thing to see if there's any latency or time drift occurs from the communication. When you start recording/streaming data with a Shimmer, you can sample the timestamp of the client and the sensor's timestamp when it actually starts the operation. Then, you can sample another timestamp of the client when it receives the timestamp from Shimmer so that you can see 1) the time difference of the client and the sensor and 2) how much time did it take to trigger the operation with Bluetooth connection. From these information, you may be able to consider the latency or time drift in the sensing. I hope my response makes sense!!

pmavros commented 1 year ago

Hi Ryo,

Many thanks for answering to my question, that is a great idea. I should implement this at some point. I have made a similar little applet for matlab, I am referencing your project too.

Cheers, Panos