Data loss?

Q&A forumCategory: QuestionsData loss?
Wolfgang asked 2 weeks ago

I seem to be losing data on the u-blox USB connection.
 
For this test I have enabled only the UBX protocol as USB port output, and configured only the NAV-TIMEUTC message to be output once per solution (every second).
 

cat < /dev/ttyACM0 | od -A x -t x1z -v -w28
000000 b5 62 01 21 14 00 80 11 aa 19 02 00 00 00 8a 7b fe ff e3 07 07 04 17 23 3a 37 2e 62 >.b.!...........{.......#:7.b<
00001c b5 62 01 21 14 00 68 15 aa 19 02 00 00 00 0c 7a fe ff e3 07 07 04 17 23 3b 37 9c dd >.b.!..h........z.......#;7..<
000038 b5 62 01 21 14 00 50 19 aa 19 02 00 00 00 8d 78 fe ff e3 07 07 04 17 24 00 37 cd cc >.b.!..P........x.......$.7..<
000054 b5 62 01 21 14 00 38 1d aa 19 02 00 00 00 0f 77 fe ff e3 07 07 04 17 24 01 37 3b 47 >.b.!..8........w.......$.7;G<
000070 b5 62 01 21 14 00 20 21 aa 19 02 00 00 00 90 75 fe ff e3 07 07 04 17 24 02 37 a7 ab >.b.!.. !.......u.......$.7..<
00008c 37 15 26 b5 62 01 21 14 00 f0 28 aa 19 02 00 00 00 93 72 fe ff e3 07 07 04 17 24 04 >7.&.b.!...(.......r.......$.<
0000a8 37 80 77 b5 62 01 21 14 00 d8 2c aa 19 02 00 00 00 14 71 fe ff e3 07 07 04 17 24 05 >7.w.b.!...,.......q.......$.<
0000c4 37 ed e6 b5 62 01 21 14 00 c0 30 aa 19 02 00 00 00 95 6f fe ff e3 07 07 04 17 24 06 >7...b.!...0.......o.......$.<
0000e0 37 59 4a b5 62 01 21 14 00 a8 34 aa 19 02 00 00 00 17 6e fe ff e3 07 07 04 17 24 07 >7YJ.b.!...4.......n.......$.<
0000fc 37 c7 c5 b5 62 01 21 14 00 90 38 aa 19 02 00 00 00 98 6c fe ff e3 07 07 04 17 24 08 >7...b.!...8.......l.......$.<
000118 37 33 29 b5 62 01 21 14 00 78 3c aa 19 02 00 00 00 19 6b fe ff e3 07 07 04 17 24 09 >73).b.!..x<.......k.......$.<
000134 37 a0 98 b5 62 01 21 14 00 60 40 aa 19 02 00 00 00 9a 69 fe ff e3 07 07 04 17 24 0a >7...b.!..`@.......i.......$.<
000150 37 0c fc b5 62 01 21 14 00 48 44 aa 19 02 00 00 00 1b 68 fe ff e3 07 07 04 17 24 0b >7...b.!..HD.......h.......$.<

Note how after the 5th message we only get the last part of message no. 6 (“37 15 26”). You can see there is only this one message missing/corrupted by looking at the seconds sequence: 01, 02, ??, 04, 05, 06, …
For some reason that I don’t understand this happens with some regularity, and you can see an actual pause in the console output as I am catting the serial port.
Any ideas?
 

1 Answers

What about IOREF pin ?
 

Wolfgang replied 2 weeks ago

I’m plugged on the USB port, not UART.

Anyway, found the problem: https://portal.u-blox.com/s/question/0D52p00008bo9f2CAA/zedf9p-usb-connection-on-linux