I know this has been discussed many times before, as I've read most of them. I have 2 3d Printers (Anet A8 and a Anycubic Chiron) running on a Raspberry Pi 3B, using Octoprint. Somewhere in mid-print, the Chiron will disconnect with the following error message
"2020-11-24 22:51:22,999 - Unexpected error while reading serial port, please consult octoprint.log for details: SerialException: 'device reports readiness to read but returned no data (device disconnected or multiple access on port?)' @ comm.py:_readline:2793
2020-11-24 22:51:23,008 - Please see https://faq.octoprint.org/serialerror for possible reasons of this.
2020-11-24 22:51:23,041 - Changing monitoring state from "Printing" to "Offline (Error: SerialException: 'device reports readiness to read but returned no data (device disconnected or multiple access on port?)' @ comm.py:_readline:2793)"
2020-11-24 22:51:23,094 - Connection closed, closing down monitor
So far, I have replaced the Raspberry Pi power source to a know good one supplying proper voltage and amps, replaced the data cable to a known good, shielded cable, upgraded the Octoprint to the latest known stable version, upgraded the firmware of the Chiron to the latest version supplied by Anycubic, and still continue to receive failed prints. The exact configuration running today (raspberry Pi, 2 printers, Octoprint configuration) ran perfectly for several months, then for no reason that I can find, the Chiron started dropping the serial connection to the Pi. The other printer does NOT drop the connection.
Anybody out there have an idea on why this happens? I apologize for the redundancy of this post, but I'm at a total loss on what to try next.