Author Topic: Connecting 3D printer to PC via USB  (Read 336 times)

Connecting 3D printer to PC via USB
« on: 31 March, 2021, 05:20:55 pm »
I am having trouble establishing a connection.  If I plug in a USB cable from the printer to my W10 PC it goes dingly dingly dong and I get Silicon Labs CP210x USB to UART bridge come up in device manager.  So the PC is recognising it has been plugged in.  But no matter what COM port I choose or what baud rate I cannot establish a connection.  Is there a procedure to go through, step by step, to get communication.  If it was IP I could ping but what can be used for USB?  What settings should I use - data bits, parity etc?

W10 laptop
AnyCubic i3 Mega running Marlin
Pronterface to talk to printer

Thanks

Re: Connecting 3D printer to PC via USB
« Reply #1 on: 31 March, 2021, 05:28:08 pm »
Under com ports in device manager, what do you have listed? The  baud rate should be 115200.

However, I strongly advise against printing from Windows as it'll only end in pain and failed prints. Save the gcode to an SD card. Or if your feeling inclined, set up a raspberry pi and octoprint

Re: Connecting 3D printer to PC via USB
« Reply #2 on: 31 March, 2021, 05:35:12 pm »
Yup, it's 115200 and I'm not trying to print but to try and alter setups and do PID calibration  and so on.

Kim

  • Timelord
Re: Connecting 3D printer to PC via USB
« Reply #3 on: 31 March, 2021, 05:38:09 pm »
Sounds like the typical Arduino-ish setup where you have a USB-to-serial chip talking to some microcontroller's UART.  The diagnostic tool of choice would be a serial terminal (I recently discovered the absence of HyperTerm in Windows 10, but remembered PuTTY could speak serial), preferably in combination with some sort of documentation for the serial protocol so you know what to send in the hope to get it to respond.  Sadly, the nature of asynchronous serial comms is that it can be a right pain to work out the connection parameters when you're dealing with something that only transmits in response to valid data.  If you're lucky it'll spontaneously spew data at intervals without you talking to it, and if you're really lucky it will be human readable (or at least intelligible ASCII).

FWIW, I'd be astounded if it wanted anything but 8 data bits, no parity and one stop bit.  No flow control is likely.

If it's just a question of which COM port is associated with the USB interface, I thought Device Manager showed such things...
Careful, Kim. Your sarcasm's showing...

Re: Connecting 3D printer to PC via USB
« Reply #4 on: 01 April, 2021, 10:57:37 am »
I get the driver for the printer appearing in device manager, as mentioned in the OP, which shows COM5 but that can be changed in properties advanced.  I set Pronterface to COM5 and 115200 and can confirm 8 bits no parity etc are set. 
Typical error message:

Connecting...
[ERROR] Could not connect to COM5 at baudrate 115200:
Serial error: could not open port COM5: [Error 5] Access is denied.

Kim

  • Timelord
Re: Connecting 3D printer to PC via USB
« Reply #5 on: 01 April, 2021, 12:27:44 pm »
I'd guess that something else is already using the port.
Careful, Kim. Your sarcasm's showing...