command structure usb --> marlin

[jeroen-teunissen 0]

Hello,

To write a small program to dump gcode to marlin through the usb port, how does the command structure on on the usb port looks like?

In other words, what command on the usb port do i need to make the x-stepper move 1 step to the right?

I do not want to harm our beautifull ultimaker and we do not have a test configuration, therefore i want to be a little carefull before i start dumping hex codes on the arduino.

(other movements also welcome)

 

[johank 7]

The Ultimaker shows up as a serial port om your computer. The commands to control The Ultimaker via the Marlin firmware are Plain text command called G-Code.

I don't know if a Marlin specific reference of G-code exists, but a general documentation for reprap descendant machines like the ultimaker is available at http://reprap.org/wiki/G-code.

For the actual command set you can check https://github.com/bkubicek/Marlin/blob/master/Marlin/Marlin.pde, which contains the Marlin source code for communications.

regards, Johan

 

[Daid 303]

Up-to-date command list for Marlin can be found at:

https://github.com/ErikZalm/Marlin/blob/Marlin_v1/Marlin/Marlin_main.cpp

It works by sending raw GCodes over USB-Serial. The code Cura uses to send the commands can be found at https://github.com/daid/Cura/blob/SteamEngine/Cura/util/machineCom.py

 

[jeroen-teunissen 0]

Thanks a lot! I am preparing an experiment, as soon as the printer is available i will try some nice ideas. I will revert.

 

[gr5 2,004]

You might want to also look at printrun and pronterface which make it easy to send gcodes to the printer. printrun is command line and pronterface is the GUI version of the same program. It's free.

 

[jeroen-teunissen 0]

Working, but getting a lot of garbage from the UltiMaker. Reading a lot of documentation, i guess most used baudrate is 115200 @ 8N1. Is that safe to assume to be working ?

 

[illuminarti 18]

The baud rate is fixed when the firmware is compiled. 250000 is generally used for Macs and Windows connections. I think the 115200 baud versions of the firmware are used with Linux machines because there are (were?) problems getting the kernel to reliably support higher speeds.

So, you need to know what speed the firmware is expecting you to talk to it, and then talk at that speed, or else you'll get gibberish.

 

[jeroen-teunissen 0]

yes, understood but i'm getting more bytes than just 'ok.' after my commands. Random garbage, not something i would expect to receive. There's not an exceptional amount of RF on the (short) cable, i guess, but i could try a shielded one.

SPEEDrx == SPEEDtx.

 

[Daid 303]

Are you sure you are receiving that and that it's not your software? Maybe you are not NUL terminating your strings?

 

[jeroen-teunissen 0]

Yes i did, in fact i tried 0x00, 0x0A en string '

' (2 bytes) as termination. I'm too busy to really pay the attention it deserves, but as soon as i can spent some time i will revert to it.

 

[jeroen-teunissen 0]

At this time, i'm able to dump a .gcode file to the ultimaker, but synchronization is still an issue. I'm getting garbage back along with the "ok." Or sometimes nothing.

Strange things happening, i'm in doubt about the CDC/ACM driver i'm using.

Separate command nicely handled, files not (yet).

To be continued.