user6841: I have connected two arduinos to /etc/ttyUSB0 and /etc/ttyUSB1.
Only one is visible in Arduino IDE. Why and how to force second?
UPDATE
$ ls -l /dev/serial/by-id
total 0
lrwxrwxrwx 1 root root 13 Jan  6 23:32 usb-1a86_USB2.0-Serial-if00-port0 -> ../../ttyUSB1

I.e. it shows port, which IS NOT SHOWN in Arduino IDE (only /dev/ttyUSB0 is shown.
ALSO
I can see both ports if run arduino with sudo. Should I run it with sudo?
Permissions are same
$ ls -l ttyUSB?
crw-rw-rw- 1 root dialout 188, 0 Jan  6 23:26 ttyUSB0
crw-rw-rw- 1 root dialout 188, 1 Jan  6 23:39 ttyUSB1


user37857: You have to add use your user to the dialout group, as explained in the installation instructions for Linux.
sudo usermod -a -G dialout $USER

Then log out and back in again.

6841: <p>I have connected two arduinos to <code>/etc/ttyUSB0</code> and <code>/etc/ttyUSB1</code>.</p>

<p>Only one is visible in Arduino IDE. Why and how to force second?</p>

<p><strong>UPDATE</strong></p>

<pre><code>$ ls -l /dev/serial/by-id
total 0
lrwxrwxrwx 1 root root 13 Jan  6 23:32 usb-1a86_USB2.0-Serial-if00-port0 -&gt; ../../ttyUSB1
</code></pre>

<p>I.e. it shows port, which IS NOT SHOWN in Arduino IDE (only <code>/dev/ttyUSB0</code> is shown.</p>

<p><strong>ALSO</strong></p>

<p>I can see both ports if run <code>arduino</code> with sudo. Should I run it with sudo?</p>

<p>Permissions are same</p>

<pre><code>$ ls -l ttyUSB?
crw-rw-rw- 1 root dialout 188, 0 Jan  6 23:26 ttyUSB0
crw-rw-rw- 1 root dialout 188, 1 Jan  6 23:39 ttyUSB1
</code></pre>
 37857: <p>You have to add use your user to the dialout group, as explained in the <a href="https://www.arduino.cc/en/Guide/Linux" rel="nofollow noreferrer">installation instructions for Linux</a>.</p>

<pre><code>sudo usermod -a -G dialout $USER
</code></pre>

<p>Then log out and back in again.</p>
