Raspberry Pi target - Error connecting to SSH server at xxx.yyy.zzz.www

Dear Colleagues,

I am setting up a testbed with a Raspberry Pi (RPi) and a Windows PC host. . Due to company policies I have had to set up the testbed as follows:

1. Assigned static private IP addresses to the Windows PC host and RPi.
2. The RPi and Windows PC host are connected with cables to an unmanaged switch.
3. The wifi and bluetooth radios on the RPi are disabled.
4. The RPi runs the uncomplicated fiirewall (ufw) with a rule that allows connections from the Windows PC host on any ports
5. Password-less SSH connections are allowed from the Windows PC host to the RPi.
6. Password authentication is disabled on RPi, i.e., PasswordAuthentication no in the /etc/ssh/sshd_config file

When I try to build the executable (elf) with ert.tlc for the RPi target I encounter the follwing error

Top model targets built: Model Action Rebuild Reason ==============================================================================

MMM Failed Code generation information file does not exist.

0 of 1 models built (0 models already up to date) Build duration: 0h 0m 15.784s

Error connecting to SSH server at xxx.yyy.zzz.www

Component:Simulink | Category:Block diagram error

In the above xxx.yyy.zzz.www is the IP address of the RPi. I am able to SSH from the Windows PC host command window to the RPi without a problem.

I am writing to ask

1. If anyone has encountered the connection error with a password-less ssh set up and found a workaround.
2. Is there a way to compile and link the executable from the command window, from either MS Windows or WSL? I have looked at the files in the MMM_rtw folder and there's an unholy mix of "regular" source and makefiles and .m and .mat files that I haven't been able to unwrap. However, I have noticed that the only place where the offending IP address shows up in cleartext is MW_target_hardware_resources.h

Thank you!

B

[Bogdan Udrea]

I have experimented during the weekend and confirmed that with my wired network configuration I can compile, link, and generate elfs if the RPi ssh daemon is set up to require password authentication with the following entries in the /etc/ssh/sshd_config

PermitEmptyPasswords yes
PermitEmptyPasswords no
ChallengeResponseAuthentication yes

I cannot compile, link, and generate elfs if the RPi ssh daemon is set up for password-less connections with public key based authentication and the following entries in the /etc/ssh/sshd_config

PasswordAuthentication no
PermitEmptyPasswords no
ChallengeResponseAuthentication no

Once I get a reply from the MathWorks tech support I'll post an update.

Cheers,

B

Answer 1

[Bogdan Udrea]

I have received confirmation from MathWorks Tech Support that a SSH with a password is required between the host (or development) computer and the Raspberry Pi target. There are no workarounds.