Check port of Arduino board

Sometimes the Arduino or other devices connected to the PI over USB get a different port assign by the system. If the standard port /dev/ttyUSB0 does not work it is possible that it got assigned a different port number.

To see what port the Arduino is on we can use ls /dev/tty* (* is a wildcard, giving us al listings with anything after the *). In this case, the Arduino Uno we use is usually at /dev/ttyUSB* where * will be a number and most of the time is 0.

pi@ixe05 ~/sketchbook/blink $ ls /dev/ttyUSB*
/dev/ttyUSB0

This tells us that we have a port at /dev/ttyUSB0.

Sometimes the Arduino can be found under /dev/tty/ACM* and the like. If the Arduino still does not show up there is one more thing to try on the port side.

1. Disconnect the Arduino
2. Run the command ls /dev/tty*
3. Connect the Arduino
4. Run the command ls /dev/tty* again
5. Finally, compare the two lists that were generated and see which device tty port was added. This is likely the connected Arduino.