Jetson Nano RS-485 transfer message

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
1

Hi,

I’m testing RS-485 on Jetson Nano and I have some questions

The Jetson Nano has the ttyTHS1 and ttyTHS2 for RS-485

I tried to transmit message from THS1 to THS2, but the messages only showed 15 words

The 16th exceed words and even over will be showed as garbled characters

This situation did not happened when I transmit message from THS2 to THS1

What is the reason for this?

And is it normal for RS-485 function?

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3

I have found the similar issue for this

After I set the baud rate to 57600(my origin setting is 115200), the garbled characters disappear

Is there any possible baud in 115200 and there’s no garbled characters?

4

hello zax0220jecht,

please have a try to disable getty service,
$ sudo systemctl stop nvgetty.service
$ sudo systemctl disable nvgetty.service

and, use the commands to have getty service running in the background manually.
$ sudo /sbin/getty -a ubuntu -L 115200 ttyTHS<port> &

5

Hi Jerry,

I used the command to check the service is using or not, but there’s no process using this service
$ sudo ps aux | grep nvgetty

What is the function of command you offered?
$ sudo /sbin/getty -a ubuntu -L 115200 ttyTHS &

6

Hi

I have another question

Is Jetson Nano serial port support the speed up to 115200?

I have check the kernel souce code and saw the correspond baud rate setting

But I can’t set 115200 baud and transmit message successfully

Only if the 57600 baud can work

7

hello zax0220jecht,

the default bardrate is 115200/8n1 for UART console.

9

Hi Jerry,

I found the route cause in the dts

I comment out these two lines in platform by reference the dts of soc and it works normally without garbled characters

platform

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soc

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image741×307 48.6 KB

Thanks for your great help

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10

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