Repetier host connecting to Rambo but not moving the motors

Mostly Printed CNC - MPCNC Troubleshooting
1

Hello,
I’ve been banging my head on this one a while. I have a MPCNC, Rambo 1.4 board, where I can control the motors with the LCD. However, I’m unable to use Repetier to control it from my (Ubuntu 20) laptop. I have been able to flash the firmware of the Rambo from my laptop, so I know I can connect to it.
I can even connect to it from Repetier successfully (upper left corner “Connect” button). But when I manually try to control the motors, everything is unresponsive and I get some error messages:

“No start signal detected - forcing start”

And then later after trying to send some movement commands:

“Communication timeout - reset send buffer block”

I’ve googled around and tried to change the baud rate (currently and by default set to 250000) without success. I’m not sure what else to try so wanted to ask for suggestions.

I’m also not married to Repetier and would be happy to try to use some other software that runs on Linux.

Thank you!
Matt

2

RH tells you it is connected, but the messages suggest otherwise.

My first guess is a permissions issue. Are you in the dialout group? Are you connected to the right port?

You can also just use miniterm to connect. Send a few enters and it should respond with ‘ok’. Find the right port by looking at the last few lines of dmesg after plugging it in.

Pronterface and pronsole work great if you like that sort of thing. Cncjs works well too.

1 Like
3

Hi Jeff,
Thank you for the suggestions! I’ve verified that I’m in the dialout group, and I have been talking to the correct COM port (used auto as well as specific port names in the printer config settings). I will move on to using miniterm and dmesg to see if I can troubleshoot it further.
Thanks for the suggestions!
Best,
Matt

4

Well, dmesg seems to say my OS is recognizing the board when I connect to it:

[ 2116.958615] usb 1-9: reset full-speed USB device number 3 using xhci_hcd
[ 2268.638850] usb 1-4: new full-speed USB device number 5 using xhci_hcd
[ 2268.790578] usb 1-4: New USB device found, idVendor=27b1, idProduct=0001, bcdDevice= 0.01
[ 2268.790594] usb 1-4: New USB device strings: Mfr=1, Product=2, SerialNumber=220
[ 2268.790600] usb 1-4: Product: RAMBo
[ 2268.790604] usb 1-4: Manufacturer: UltiMachine (ultimachine.com)
[ 2268.790608] usb 1-4: SerialNumber: 855373037303512181A1
[ 2268.881927] cdc_acm 1-4:1.0: ttyACM0: USB ACM device
[ 2268.881953] usbcore: registered new interface driver cdc_acm
[ 2268.881954] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters

So I’ll do some more testing with miniterm. Right now just getting garbage characters back so I might need to change the baud rate.

5

Ok, miniterm seems to connect correctly once I set the correct baud rate.
I was even able to jog the motors with commands like G0 X1

However, still no love from Repetier host

Miniterm output:


matt@mattsputer:~$ miniterm - 250000

--- Available ports:
---  1: /dev/ttyACM0         'RAMBo'
--- Enter port index or full name: 1
--- Miniterm on /dev/ttyACM0  250000,8,N,1 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
start
Marlin 515D 2.1.1
echo: Last Updated: 2022-08-06 | Author: (V1 Engineering, Ryan, 515D)
echo: Compiled: Jan 11 2023
echo: Free Memory: 3074  PlannerBufferBytes: 1664
echo:DIGIPOTS Loading
echo:DIGIPOTS Loaded
echo:DIGIPOTS Loading
echo:DIGIPOTS Loaded
echo:V86 stored settings retrieved (589 bytes; crc 31952)

— exit —

Short of any other solutions, I’ll try another CNC client program next

6

I’m going to install repetier host since at this point something points to the app itself needing some help. Thanks Jeff for helping me troubleshoot!
Will report back how it ends up.

7

Ok, it’s working now. The solution was to upgrade to the latest version. For some reason, when I first installed it using the AppImage file, I wasn’t able to install the latest version so had to go back 1 to the previous version. That was the issue. When I installed from the tgz file the latest version worked. So the lesson in this case was not to use the AppImage file and run from the gzip archive with the configuration script, which is probably what made the difference.

Thanks for all the help!

8

Interesting. I honestly haven’t used RH in Linux in several years. I use pronterface to get it started and then I connect a pi and use my v1pi image.

I also use miniterm from time to time, but my brain works in weird ways sometimes.

Glad you got it working.

9

OOPS I missed your follow up post stating you got it working until I reread all the replies. Ill leave this in case it helps someone.

So I just tried RP-H for the first time Linux Mint 21.1 Downloaded AppImage last few days, (v2.3.1) and it took a bit for me to get it working. I could not even “Connect”. When I launched from CLI the AppImage is was giving an IOException: Permission denied.
Yours may be a different issue but… here’s what I did in case it helps.

What worked:

Summary: (All probably not needed)

  • start appimage with the first time using “-prepare” per download instructions (I missed). " If you never have run a host software with your user run it once with parameter “-prepare” to put your user into dialout group and reboot."

  • Disabled Firewall - probably not needed

  • Add Myself to groups: dialout, tty, uucp

  • FULL REBOOT of laptop

It connected from there for me. Using USB and “Serial Connection” defaults "/dev/ttyAMC0, 250000 baud, …I did not change anything else. I am guessing since I only tried logout and not a full reboot that maybe only -prepare and dialout group are required.

I loaded a file. I could not figure out how to “move” the object or even nudge the router to a desired location. I had to load a file and clicking start then “stopping” it. Luckily it cut too HIGH Z. Not sure how this is SUPPOSED to work. When I put the same file, from the same card into the LCD it cuts fine.I never did feel brave enough to click whatever the little router bit looking icon with up/down arrows was. Perhaps spindle speed. Maybe if I had internet in the shop I could have figured something out but the phone gets old. I gave up and went back to LCD.