Recently I bought ioptron CEM 40 mount. I am trying to connect kstars/ekos to this mount but getting this error below. Attaching the logs as well. I would really appreciate if someone can help with this issue.
2022-01-29T04:20:34: [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.
Many people using a CEM40 + pi (including ASIAir Pro) have a similar issue. If you try to connect the CEM40 directly to a usb port on the pi, it fails to be recognized during boot-up. If you look at lsusb before starting KStars, the mount will not be there (when it is there, you see an entry for an FTDI usb to serial device). If you look at dmesg, it tries to connect and reports "maybe bad usb cable?".
Either there is something about the usb hub inside the mount that the pi OS usb drivers do not recognize, or (maybe more likely) the mount is trying to draw more power through usb than the pi can provide. So people end up with a powered usb hub in between the pi and the mount.
I also have trouble staying connected to a CEM40, as described above. In my connection tab, in System Ports, I see FT230X_Basic_D3093ZS7
A longer string containing that is in the Ports line. If I click on System Ports, it turns green. Scan Ports results in the message "one port found".
Is there some meaning to System Ports always starting not-green? Have I done anything by clicking on it, besides making a nice green color?
edit: It would appear that I have not done anything useful by turning System Ports green, as after a few minutes there was another Read command time-out error
So many variables in this, and so hard to do experiments.
There's the "pi won't talk directly to the mount" - is that fully corrected by using a hub, or not? Any hub, or just some hubs? If it connects at all, does that mean that the pi - hub - mount communication is settled, and any further communication issues lie elsewhere?
There's some people reporting that the iOptron cable is a problem (even maybe with windows?).
There's the fact that most type-B cables do not fit snugly into the mount's female type-B. The iOptron cable fits best, but still moves around easily when fully engaged.
There's the fact that I have had many hours of successful indoor testing with the same cable setup that failed quickly outdoors (maybe something about the cameras? saw one ASIAir message board post that swapping out the 12v supply they were using for cameras seems to have fixed their connection issue) / (maybe temperature? - but I had a couple of successful evenings late December, they were about as cold as last night).
Current test is in the garage, so not as cold as outside but much colder than the house, with no cameras. I started with the iOptron cable, but snugged up to the 12v plug using velcro as suggested by someone on fb - the idea being to provide some side-load to keep the plug from moving around enough to cause momentary loss of continuity. The fact that lsusb continues to show the mount and iPolar even while getting read timeout errors says that the connection never gets totally lost, but wiggly usb connections are an obvious potential problem.
Left it powered on overnight, with the mount not actually doing anything. It threw read timeout errors all night, averaging one about every 15 minutes, but the driver never crashed and the mount would still respond to commands in the morning. Better, but not confidence-inducing.
Swapped a non-iOptron type-B cable I was using earlier, but now snugged up with the velcro. It has been tracking for 3 hours now with no read errors, so that's encouraging - but experience tells me not to declare this to the the real solution.