Greetings to all fellow ROS answers members,

I am trying to familiarized myself with the usage of ROSbot 2.0 pro by following the ROS tutorials provided on the Husarion website.

While progressing through https://husarion.com/tutorials/ros-tu... I faced the following problem...

Troubled command

roslaunch rosbot_ekf all.launch rosbot_pro:=true

Error generated

Unable to sync with device; possible link problem or link software version mismatch such as hydro rosserial_python with groovy Arduino

I tried to solve this issue based on the following four approaches...

1st approach: Updates and upgrades

sudo apt-get update sudo apt-get upgrade

Results:

• Spent about 10mins on the upgrade
• Tried running the command that has issue, error still retains.

2nd approach: Update rosserial-python and rosserial-arduino

sudo apt-get install rosserial-kinetic-python sudo apt-get install rosserial-kinetic-arduino

Results:

• no upgrades required for python, but there was one upgrade for arduino
• Tried running the command that has issue, error still retains.

3rd approach: Ensure baud rate and serial port compatibility

Based on the command which triggered the error, looking into the "all.launch" file from the "rosbot_ekf" package.

serial_port value="/dev/ttyS4" serial_baudrate value="460800"

Looking into the "arduinoHardware.h" file from the "rosserial-arduino" package. It was noticed that their baud rate was indeed different.

ArduinoHardware(SERIAL_CLASS* io , long baud= 57600)

baud_ = 57600;

Since the error mention the possible mismatch of rosserial-python, I went to analyze the "serial_note.py" file from the "rosserial-python" package. But I believed these parameters will ultimately get overwritten by the "all.launch" file with its inputted values.

port_name = rospy.get_param('~port','/dev/ttyUSB0') baud = int(rospy.get_param('~baud','57600'))

.. Procedure A Edit the "arduinoHardware.h" file to match according to the "all.launch" file baud rate values

sudo nano arduinoHardware.h

Results: Tried running the command that has issue, error still retains.

.. Procedure B Edit the "all.launch" file to match according to the "arduinoHardware.h" file baud rate values

nano all.launch

Results: Tried running the command that has issue, error still retains.

(p.s. Perhaps I missed out a mundane step for both A and B. I understand sometimes you need to do a catkin_make? )

4th approach: Ensure serial port is in the correct baud rate

This command checks the baud rate of the serial port

stty -F /dev/ttyS4

This command sets the baud rate for the serial port

stty -F /dev/ttyS4 57600

Results: Tried running the command that has issue, error still retains.

Conclusion After trying all these solutions, I think my case does not lie with the issue of baud rate or serial port compatibility, likely to be software version mismatch.

May I kindly know how can I further diagnose this error?