The three most frequent reasons a printer won't connect to your AstroBox are:
- Incorrect Baud Rate.
- Incorrect connection timeout.
- Bad Psychical connection.
- Incompatible printer.
It's a good idea to learn how to debug the serial port to troubleshoot comms problems.
Let's take one by one:
Incorrect Baud Rate
Most printers function at either 250000 or 115200 baud rates. When the incorrect baud rate is set, the printer won't received the commands properly and its responses will appear as garbage.
Monitor your serial logs when you're trying to connect to see if clear text is coming back from the printer. If not, change the baud rate in Settings -> Printer Connection and try again.
Incorrect Connection Timeout
You should see your printer resetting due to a new USB connection, then a M105 command will be sent and finally the printer response comes. If this response doesn't come before the specified Connection Timeout, the AstroBox software reports a connection error.
The AstroBox software comes pre-configured with a pretty generous connection timeout of 10 seconds. However some printers might take longer to reset and respond. Below are the steps to increase the timeout.
1. Connect to your box's command line by either ssh or connecting a monitor and keyboard.
2. Execute the following commands:
# sudo service astrobox stop # sudo nano /etc/astrobox/config.yaml
3. Add the following line to the serial section (2 spaces indentation):
serial:
timeout:
connection: 15
4. CTRL-X + Yes to save the file and execute the start command:
# sudo service astrobox start
The software will now wait 15 seconds before giving up. Note that if this is not successful, it could still be due to one of the other issues described in this article.
Bad Physical Connection
If your USB cable quality, location or board power supply are not good, communication problems will happen. The things to check for here are the same as described in this article.
Incompatible Printer
The list of known compatible printers is here, please check it out first.
We support two types of firmware: GCODE based (Marlin/Repetier) or S3G based (Sailfish), make sure the right driver is selected in Settings -> Printer Profile.
Unfortunately some printers implement a proprietary interface that we can't communicate with, in those cases there's not much we can do without collaborating with the printer manufacturer. If you have one of these machines, please contact your manufacturer and let them know that you'd like to use AstroPrint with their machine. When enough users do that, they'll work with us to make it compatible.