Timestamp jump in the raw data

rittmorittmo Sverige
in Cyton
Hello. When recording with a frame rate of 250 with the cyton board and dongle there are arbitrary time jumps in the raw data file of about 200-400 ms in the timestamps. At first we thought it was due to the bluetooth but after having compared the datafile from the GUI to the datafile written to the SD-card which looks the same we realised this can't be the case. We can't figure out why this is and how to solve it. Someone else that have encountered this? Could this be just a fault in the output of the timestamp or does this mean that we do not have data between these time stamps?

Look at the timestamp at 19:02:44.071 and the one after.
221, -22729.62, -10545.33, -82978.08, -77797.44, -96769.37, -113060.71, -64416.52, -89388.34, 0.000, 0.000, 0.000, 19:02:44.071
222, -22731.79, -10547.77, -83013.08, -77815.18, -96763.41, -113046.40, -64420.95, -89374.41, 0.000, 0.000, 0.000, 19:02:44.071
223, -22760.11, -10557.64, -83086.62, -77874.75, -96753.26, -113026.78, -64473.09, -89354.00, 0.000, 0.000, 0.000, 19:02:44.071
224, -22730.20, -10534.29, -83094.93, -77889.68, -96716.58, -112994.61, -64490.19, -89355.05, 0.000, 0.000, 0.000, 19:02:44.071
225, -22715.99, -10530.84, -83030.78, -77853.00, -96736.80, -113016.72, -64444.59, -89383.77, 0.000, 0.000, 0.000, 19:02:44.517
226, -22723.19, -10540.75, -82959.59, -77815.67, -96775.36, -113053.16, -64381.45, -89404.34, 0.000, 0.000, 0.000, 19:02:44.517
227, -22727.70, -10534.80, -82987.64, -77835.79, -96735.48, -113025.52, -64386.07, -89367.14, 0.000, 0.000, 0.000, 19:02:44.518

Thanks in advance

Comments

  • wjcroftwjcroft Mount Shasta, CA
    Have you set the Latency or buffering setting for your serial port, to avoid the stuttering?


    Fixing FTDI InBufferSize for OS X
    OpenBCI on Windows
  • rittmorittmo Sverige
    Ahhh! Thank you so much! Do you have got a clue of why the voltage values were the same in the data file from the SD-card since there should be no latency there right?
  • BillhBillh
    For each data line, the SD card write and serial port write may be written one after the other via what is coded as a single-threaded loop, so perhaps a delay in one delays the next.

Sign In or Register to comment.

© Vanilla Keystone Theme 2026