Serial port 1 data loss occasionally

Hi,

I send data form PC to nano carrier board kit(UART1-pin6/8/10 of J41) per second, but occasionally the data loses frames, such as,
I send 12345 form pc per second, but nano kit display

12345
12345
45
12345
Some or all of the data will be lost!
But send data to PC form nano , it is without error.
Does anybody encounted the problem or know what’s going on?

Thanks!

hello yzh03,

may I know which JetPack release you’re working with,
could you please also share your serial port configuration for reference.
thanks

Hello JerryChang,

We are working with JetPack 4.2.1, and the serial port configuration is as follows:

~$ sudo stty -F /dev/ttyTHS1 -a

speed 115200 baud; rows 24; columns 80; line = 0;
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; eol = ;
eol2 = ; swtch = ; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;
-parenb -parodd -cmspar cs8 hupcl -cstopb cread clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl -ixon ixoff
-iuclc -ixany -imaxbel -iutf8
-opost -olcuc -ocrnl -onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
-isig -icanon -iexten -echo -echoe -echok -echonl -noflsh -xcase -tostop -echoprt
-echoctl -echoke -flusho -extproc

Thanks!

hello yzh03,

we would like to setup an environment to reproduce the issue,
could you please also share the tool or the script files to send data form host-pc per second.
thanks

Hello JerryChang,

We use the TTL-USB convertor to connect nanokit to PC, and use serial tool “serial port utility” to send data “12345#” per second loop.
The terminal enter “sudo cat /dev/ttyTHS1” after nano is started, and it displays data such as “5#2345##45#45#12345#2345#12345#2345"etc, but no"12345#12345#12345#12345#12345#”.

Thanks!




Hello everyone,
Has anyone tested nano kit serial 1 (UART1 on J41), is there anything wrong ?

hello JerryChang,
Did you repeat the experiment, does your kit work properly ?

Thanks to all !

hello yzh03,

confirmed we could also reproduce the failures on the Nano devkit.
we’re arrange resources to investigate this, will update the status after we come out conclusions.
thanks

here!

I have a similar problem on using /dev/ttyTHS1 (J41)

Hi,

Yes, I am also facing the exact same issue and am also using /dev/ttyTHS1. Except that I am using the production Nano module with a custom-made carrier board. The signal integrity on the hardware was verified though. I am using R32.2 sources kernel and building it, then flashing it via the flash.sh script. This is needed because there are some custom drivers I need to use.

Anyway… any pointers regarding this issue would be appreciated.

Thanks.

You may try this.

That fixed the issue I was facing. Thank you so much!

hi all,

FYI,
serial data is being transferred properly without any data loss with execute getty running at background,
for example, on Jetson-Nano.

$ sudo /sbin/getty -a ubuntu -L 115200 ttyTHS<port> &

systemctl stop nvgetty
systemctl disable nvgetty

We stop the nvgetty service and it works well.

Thanks!