I recently bought CEM 40 and facing the same issue with this error I pasted below. I am using astroberry (rpi4). I would really appreciate if someone can help with this problem.

Thanks

I just received CEM40 today. My rasberry pi4, too, does not recognize it. It says: [ERROR] Failed to connect to port (/dev/ttyUSB0). Error: Port failure Error: No such file or directory. Check if device is connected to this port.
Please help.

P.S. My firmware version is: 210605. I think it's the newest.

Use port selector and select a port from the dropdown list. Maybe baud rate 115200

What power source you power up raspberry pi4? Pi4 is power hunger. It may not have sufficient to power USB device plugged in. You can add a active USB hub in between Pi4 and CEM40.

Kenny

This may not be the problem nor solution - I debugged this *endlessly* with my GEM45, and a powered hub didn't help (but I did spend money!).

See the culmination of my mostly-complete "saga" here .

The USB to RJ12 adapter however did *not* work, and the guiding issues were because I suck at polar alignment.

I did run into the "[ERROR] Failed to connect to port (/dev/ttyUSB0). Error: Port failure Error: No such file or directory. Check if device is connected to this port." problem as well - it was because the Pi couldn't assign it a USB adapter correctly, iirc because of the mount itself (was often the problem with the GEM45 when going direct-to-mount with the Pi).

You can see this on the Pi4 terminal by running:
Then plug in the mount however you are doing this via USB - you can see what that will likely look like here if you are experiencing the same problem I was.

TL;DR: Grab a cheap, *unpowered* USB hub (I linked directly to the one I ended up using) and try that - it may save you a massive amount of headache / money-spending. You can see in my other post(s) that I ended up getting a different USB cable as well, but that did not work by itself (it required the unpowered USB hub).

I have selected every baud rate possible, but the problem persists.

Edit: this is a reply to Jasem Mutlaq

I used many types of power sources (home outlet and two power banks with different usb cables.) In addition, I tried an unpowered usb hub. Pi4 still cannot detect the mount. The mount works with Ioptron Commander 7.0 with my laptop with Windows10 fine.

Edit: this is a reply to KENNY WONG.

I have tried an unpowered usb hub. It does not work. I may have to try your solution later, but it will take sometime to have the hub delivered to me.
As far as I see I may try:
- your unpowered usb hub,
- a new usb cable,
- or buy a rasberry pi3.

Edit: this is a reply to MH

Try `dmesg -Tw` on the command line while swapping cables out, that may give you more information around the Pi actually detecting / allocating the USB port correctly (or not) at least.

I also recall running into weird issues where just having the cables plugged in during boot versus plugging in after would sometimes cause problems, but I wasn't able to delve into that further to figure out if that was actually the cause or not =(

I found an unpowered usb hub and tried it. My Pi4 has started to see the mount, but the connection is not very stable. I will try your recommended hub (finger-crossed.)
Thank you for your reply. Please keep it coming.

Can do!

I am more than happy to help - I think I lost some significant chunk of my overall life expectancy getting the GEM45 working, so if I can save anyone even a fraction of that grief, it's worth it haha

[Tue Apr 12 18:56:51 2022] usb 1-1.3.3: clear tt 4 (9051) error -71
[Tue Apr 12 18:56:51 2022] usb 1-1.3.3: clear tt 4 (9051) error -71
[Tue Apr 12 18:56:51 2022] usb 1-1.3: USB disconnect, device number 23
[Tue Apr 12 18:56:51 2022] usb 1-1.3.3: USB disconnect, device number 34
[Tue Apr 12 18:56:51 2022] usb 1-1.3.3.3: USB disconnect, device number 35
[Tue Apr 12 18:56:51 2022] usb 1-1.3.3.4: USB disconnect, device number 36
[Tue Apr 12 18:56:51 2022] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
[Tue Apr 12 18:56:51 2022] ftdi_sio 1-1.3.3.4:1.0: device disconnected
[Tue Apr 12 18:57:02 2022] usb 1-1-port4: Cannot enable. Maybe the USB cable is bad?
[Tue Apr 12 18:57:03 2022] Under-voltage detected! (0x00050005)
[Tue Apr 12 18:57:03 2022] usb 1-1-port4: Cannot enable. Maybe the USB cable is bad?
[Tue Apr 12 18:57:03 2022] usb 1-1-port4: attempt power cycle
[Tue Apr 12 18:57:04 2022] usb 1-1-port4: Cannot enable. Maybe the USB cable is bad?
[Tue Apr 12 18:57:05 2022] usb 1-1-port4: Cannot enable. Maybe the USB cable is bad?
[Tue Apr 12 18:57:05 2022] usb 1-1-port4: unable to enumerate USB device
[Tue Apr 12 18:57:07 2022] Voltage normalised (0x00000000)


It says "Under-voltage detected" when not using the usb hub.