Measure large latencies

cbachhuber / G2GDelay

Glass-to-Glass delay measurement system

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Measure large latencies #15

Open joshua-glazer opened 2 years ago

joshua-glazer commented 2 years ago

I'm working on an application in which we need to measure latencies that can be longer than 1 second, however from my understanding of the current Arduino code, the maximum latency it can measure is 524ms. The goal here is therefore to:

[ ] Determine a good approach for measuring large latencies
[ ] Update the README to describe the ability and limitations of measuring the delays, perhaps explaining how to adjust the max latency

joshua-glazer commented 2 years ago

As suggested by @cbachhuber two approaches could be:

lowering the sampling rate. Simple, less accurate, doesn't fully solve the problem, only scales it. There might be other parameter changes necessary as well
Using PT_voltages as circular buffer: after you run over the end of the sample array, overwrite the oldest values at the front with new values. Detection and ending code also needs adaptation. Complex, accurate, solves the problem altogether.

wpeirkcfj commented 7 months ago

I am very interested in your Glass to Glass Delay Measurement System project and bought my own equipment to try to reproduce it. But after setting up this project, I found that during the test delay process, if the system works normally when the LED is placed directly on the PT, it is normal to shoot the LED through the mobile phone screen and then use the PT to receive it, but when the LED is placed The system does not work properly when on the computer screen. PT cannot receive the light displayed by the LED through the computer screen. I was wondering if you could help me with this. I sincerely appreciate your help and guidance. Warm regards, @cbachhuber @joshua-glazer

cbachhuber commented 7 months ago

Hey @wpeirkcfj, thanks for you request! I see your issue as separate from the one being discussed in this thread, so let's resolve your issue in https://github.com/cbachhuber/G2GDelay/issues/23.