UART Port broken, what should I do?

[mlebret (Marc Lebret)]

@abdulrfahim.fahim

So the application here would be USB to TTL right? I’m sorry, I’m not very well versed in reference to the picture you posted.
And you also said that TXD on telemetry-ground-station should be connected to RXD flash-adapter and RXD on the telemetry-ground-station should be connected to TXD flash-adapter? correct?

All is correct. It should work…

[abdulrfahim.fahim (Abdul Fahim)]

That’s the thing. I receive the error: “No heartbeat found”.

[abdulrfahim.fahim (Abdul Fahim)]

Btw my baudrate is 57600 if that is anything important. The telemetries are connected since the light is then are solid green. But the above error is given. If you know something, please do tell.

[abdulrfahim.fahim (Abdul Fahim)]

Hmmm… I get the following error now.

Blockquote arducopter.service - ArduPilot for Linux
Loaded: loaded (/etc/systemd/system/arducopter.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2019-12-13 01:42:37 UTC; 7min ago
Docs: https://docs.emlid.com/navio2/navio-ardupilot/installation-and-running/#autostarting-ardupilot-on-boot
Main PID: 3434 (sh)
CGroup: /system.slice/arducopter.service
├─3434 /bin/sh -c /usr/bin/arducopter $TELEM1 $TELEM2
└─3435 /usr/bin/arducopter -A udp:127.0.0.1:14550 -C /dev/ttyUSB0

Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error
Dec 13 01:50:10 navio sh[3434]: Failed to open UART device /dev/ttyUSB0 - Input/output error

Blockquote

[bide]

This is just generic advice. Post the output of these commands:
whoami
ls -l /dev/ttyUSB*
cat /etc/group | grep dialout
lsof | grep ttyUSB0

What they do:

1. show your user name
2. show your USB adapter(s) and what user owns them
3. check to see if your user name is a member of the ‘dialout’ group
4. check to see if any other programs are using the USB adapter(s)

[abdulrfahim.fahim (Abdul Fahim)]

Hey, the following are the outputs, the last one though gives an error.

@bide

This is just generic advice. Post the output of these commands:
whoami
ls -l /dev/ttyUSB*
cat /etc/group | grep dialout
lsof | grep ttyUSB0

pi@navio:~ $ whoami
pi
pi@navio:~ $ ls -1 /dev/ttyUSB*
/dev/ttyUSB0
pi@navio:~ $ cat /etc/group | grep dialout
dialout:x:20:pi
pi@navio:~ $ lsof | grep ttyUSB0
-bash: lsof: command not found

The last command outputs an error.

[bide]

The error just means lsof is not installed on your pi.

In the first command, could you change the “dash one” to “dash ell” (lower-case):
ls -l /dev/ttyUSB*

also:
stty -F /dev/ttyUSB0

It 1) shows ownership of the USB device, and 2) shows the current baud rate

[abdulrfahim.fahim (Abdul Fahim)]

@bide

In the first command, could you change the “dash one” to “dash ell” (lower-case):
ls -l /dev/ttyUSB*

also:
stty -F /dev/ttyUSB0

It 1) shows ownership of the USB device, and 2) shows the current baud rate

pi@navio:~ $ ls -ell /dev/ttyUSB*
ls: invalid option – ‘e’
Try ‘ls --help’ for more information.
pi@navio:~ $ stty -F /dev/ttyUSB0
stty: /dev/ttyUSB0: No such file or directory

Both resulted in error of some kind.

[bide]

I think the representation of the character fonts is getting you messed up.

*here’s a couple of hints for ls -l /dev/ttyUSB*

1. the -1 is not -1 and it is not -ell. It is a dash followed by a lower-case letter ell.
   Letter Names in the English Alphabet and How to Spell Them

2. These are numerals 1,2,3,4. These are letters l,m,n,o. You want the letter “l”

[abdulrfahim.fahim (Abdul Fahim)]

pi@navio:~ $ ls -l /dev/ttyUSB*
ls: cannot access ‘/dev/ttyUSB*’: No such file or directory

Error!

[bide]

I suppose this means your USB device has been disconnected. Maybe unplug it and plug it back in.

[abdulrfahim.fahim (Abdul Fahim)]

pi@navio:~ $ ls -l /dev/ttyUSB*
crw-rw---- 1 root dialout 188, 0 Dec 13 23:14 /dev/ttyUSB0

Yes you are right.

[bide]

So try this again:

@bide

stty -F /dev/ttyUSB0

[abdulrfahim.fahim (Abdul Fahim)]

@bide

stty -F /dev/ttyUSB0

pi@navio:~ $ stty -F /dev/ttyUSB0
speed 57600 baud; line = 0;
min = 0; time = 0;
-brkint -icrnl -imaxbel
-opost -onlcr
-isig -icanon -iexten -echo -echoe -echok -echoctl -echoke

[bide]

everything looks good there.

To watch data coming in the ttyUSB0 device, you could run the program ‘screen’ like so:
screen /dev/ttyUSB0

when you are done watching, to exit the program you have to press:
‘CTRL-a’ then ‘k’ and answer 'y’es to kill it

[abdulrfahim.fahim (Abdul Fahim)]

@bide

screen /dev/ttyUSB0

Nothing happened…

[abdulrfahim.fahim (Abdul Fahim)]

Simply a screen blank.

[bide]

That means there is no data coming in at 57600 baud. If there was data coming in, you would see the characters appear on the screen.

This is the end of my help. You need to find a way to troubleshoot the rest of the hardware now. This part at the pi seems fine.

[abdulrfahim.fahim (Abdul Fahim)]

Do you mean that the problem is with the telemetry? The Ground telemetry doesn’t connect with the air module?

[abdulrfahim.fahim (Abdul Fahim)]

Btw, now the baud rate is different;
pi@navio:~ $ stty -F /dev/ttyUSB0
speed 9600 baud; line = 0;
-brkint -imaxbel