@victochen , just to close the loop on the original issue.. the delay in the calibration procedure was caused by UART data or processing of the ESC feedback backing up. The fix is to just slow down the command rate, seen in this commit : https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc/-/commit/b512f9e3d5e695868775de3d40eedb2ad15cf6d9 . Additionally, using command line argument --cmd-rate 100 when you run the calibration script on VOXL2 will fix the issue.
V