Connection help

Mr.Mayday · February 25, 2021, 6:58pm

Hello,

I a STEM teacher at a public high school. We had a great couple of kids several years ago that were under the supervision of a different teacher that bought the MPCNC kit, and had some successes with it until it stopped working for some reason. I have been tasked with getting it up and running again.

I started by following the instructions from control, as the device is still assembled in all of it’s original glory.

I have been having trouble with connections with the computer in a couple of spots.

I started by downloading repetier host, but then could not make a connection to the printer.

I then downloaded repetier server, and was able to get a connection, and it even recognized it as the MPCNC, after this I was also able to get a connection from host.

When I tried to use the manual controls however, I got nothing.

I get an error that says no start up signal was received (forgive me for the lack of screenshots) and it would back log manual commands. until they eventually time out. I changed the baud rate between the 2 recommended settings and still nothing, no sound, no motion… nothing.

While checking the device manager (we are trying to run this off windows 10) I see that the arduino is recognized as USB serial device, and under the settings it says device driver not found, and It won’t download anything from the internet to make it work. After doing some research and delving down yet another troubleshooting rabbit hole, I realize that the board is not a genuine arduino mega, but a chinese clone.

I then try to download a specific driver for this device, but it fails to install.

At this point I am assuming I need to swap it out with a genuine arduino mega.

My questions to the community are, am I correct in my assumption from the sound of it? and if I do need to swap the board, does the firmware go onto the arduino, or is it already flashed to the “ramps” (red board with the yellow tabs) (apologies for the non technical description)

jeffeb3 · February 25, 2021, 7:42pm

Hi, welcome. I am sure you will get lots of support. We all love to see students and teachers here. So please don’t hesitate to ask for help. You are in a bit if a unique spot because you have not really asked for this. So hopefully you can stay with us to feed us information and learn what it takes to run this beast!

Some photos of the setup will help a ton. It helps me and others get our bearings on what you have, how it is installed and what you might be missing. You probably don’t know how to describe everything on the machine, so we can skip the middle man and get the info from the source!

I am not a windows expert, but I have not seen many people be successful with repetier server. I am wondering if maybe you have a valid connection from RH to RS, but RS may not be talking properly to the MPCNC.

I would start by uninstalling Repetier server, because whatever problem you are having connecting to the board will be more obvious with RH.

When you connect or disconnect the USB, does a new COM port show up?

We won’t know what firmware this thing has on it until we can connect. The two common baud rates are 250,000 (most common) and 115,200. You should be trying those two. If there is anything useful for debugging, it will be in the console log at the bottom of the RH screen.

The firmware stays with the mega. The ramps is a glorified wiring harness and just moves connections around to the drivers. It is not too hard to flash a new mega and you might try flashing the one you have to see if that fixes it too.

The knock off megas are very common (arduino is very proud of their legitimate ones). They sometimes have quality issues, but they generally all connect to windows 10 just fine. There was a driver needed for windows 7, but AFAIK, not since then. If you get a COM port, then I would assume that part is fine.

Do you have a screen? The screen is an easy way to get a hardware connection without having to worry about the huge windows ecosystem. There are some in the v1 shop for about $10.

jeffeb3 · February 25, 2021, 7:44pm

Instructions for flashing a board are here:

https://docs.v1engineering.com/learn/platformio/

The software can be found at MarlinBuilder releases. You probably want V1CNC_Ramps but we will know more after some pictures.

mannya · February 25, 2021, 8:14pm

Arduino clones typically use the CH140 chipset for USB to serial communications. The CH140 is notorious for dropping connections. It’s really frustrating to work with…especially on Macs. Sometimes my Mac would reboot as soon as I plugged in my arduinos.

robertbu · February 25, 2021, 8:33pm

Marlin set its baud rate at 250,000, so that is what you need in Repetier-Host. See this page for setting up Repetier-Host for the MPCNC. I’d do a bit more troubleshooting before replacing the Mega board.

ttraband · February 25, 2021, 8:38pm

It’s been my experience that Repetier Server tends to monopolize the USB connection so it’s hard to troubleshoot with that installed. I’d reinstall Repetier Host and deselect Server.

ttraband · February 25, 2021, 8:42pm

Edit - never mind. The yellow tabs are the ramps soft fuses. I read “yellow tabs” as “yellow sockets” and I’ve only ever seen those on CNC shields

A photo of the control board would be helpful too. There are a couple of Arduino options for hardware. Hearing you description you may have a CNC shield rather than a RAMPS. A photo will help us make sre we’re giving you the tight advice.

Mr.Mayday · February 26, 2021, 3:17pm

Thanks you all so much for the quick responses, I was not near the machine to reply with pictures after my post so sorry for the delay. Here is our board:

Mr.Mayday · February 26, 2021, 3:18pm

With power supply

Mr.Mayday · February 26, 2021, 3:19pm

Here is a picture of the com ports from the device manager, before and after plug-in of the arduino( that ch340 thing was not there yesterday, but that was the name of the random Chinese driver I found for the arduino clone)

Mr.Mayday · February 26, 2021, 3:19pm

Mr.Mayday · February 26, 2021, 3:27pm

And here is the error message in repetier host (I uninstalled all of the repetitive softwares, and reinstalled host while deselecting server as you advised) still no motion or response in manual control

Mr.Mayday · February 26, 2021, 3:30pm

I brought in a couple of Italian Mega’s, and am in the process of flashing them now to see if that changes anything

Mr.Mayday · February 26, 2021, 3:33pm

Also the baud rate that recognizes a connection in host is 115200

jeffeb3 · February 26, 2021, 4:41pm

Who knows what firmware is on there . 115200 hasn’t been the v1 standard for a long time. You can get the latest from MarlinBuilder releases. The V1CNC_Ramps is the right one for you. There is even a firmware.hex that you can flash using xloader (which is substantially simpler than platformio or arduino ide).