Newbie Question- Connecting RAMPS 1.4 to Mac via USB

Hello all-
This is my first day trying to hook up a reprap with RAMPS 1.4 I purchased assembled. I am trying to connect it to my Macbook Pro, via USB. It seems to want to connect as a USB modem, and Repsnapper will not connect to it. What am I missing? Thanks in advance!

Edit: More info...
I do get two green LED's on the ramps when trying to connect to the usb modem in system preferences, before it fails to connect. I also get some LED's when I press connect to printer in repsnapper. Any help would be appreciated, including suggestions on alternatives to repsnapper, and any way I can get this connected to my mac!

Edited 1 time(s). Last edit at 04/09/2012 07:06PM by xkylewrightx.

My guess is you need to set the baud rate within Repsnapper. /dev/tty.usbmodem1a21 (you may get different last four digits and letters) is the correct device to connect to a RAMPS board from a Macintosh. I used to use Repsnapper, but have found Pronterface (http://github.com/Kliment/Printrun for the latest and the pre-compiled version with Slic3r built in is at [koti.kapsi.fi]) to be much more user-friendly.

If I remember right, RAMPS 1.4, at least from Ultimachine, come with Sprinter firmware preinstalled, and it defaults to 115200 bps. Make sure your console program, either Pronterface or Repsnapper, matches this, or else you will not get a connection to the printer.

Alright, after messing around with it I tried to upload sprinter firmware onto the ramps with arduino, either it was unnecessary or it screwed it up..? Either way it compiled okay but kept timing out during the upload, dont know if the firmware is screwed up now.. any tips?

What version of Mac OSX and what version of Arduino are you using? Do not install an FTDI driver, it's not needed for the Macintosh. I am now able to use Arduino 1.0, but don't know what I did to make that work, previously I never was able to upload firmware until I installed version 0.23 of Arduino. My Mac Pro that I use to drive my printers is still on OSX 10.6.8, a Mac Air that I also occasionally use (OSX 10.7.3) has always just worked with Arduino 1.0.

In the Arduino program, under Tools/Board make sure you have selected the correct Arduino Mega, either 2560 or 1280. Then select under Tools the Seial Monitor. Does anything show up in that terminal window? If it is gibberish, you probably still have the baud rate wrong. Select that in the lower right corner of the terminal window, and then hit enter in the text box at the top, or try sending M115. When you get back readable text you will know you have the correct baud rate setting. Now you should be able to upload the firmware.

I'm using the latest version of mac leopard (10.7.3?) and version 1.0 of arduino. I havent installed a FTDI driver either.

In Arduino I have the correct board selected (Mega 2560) and the correct port (dev/tty.usbmodem411). After launching the Serial Monitor nothing is showing in it. I can change the baud rate, but nothing shows up in the output. Tried sending M115 and still nothing showed up in output

I am not sure if my ramps needs firmware, or if I messed it up by trying to put firmware on it. I could not get sprinter to compile but marlin seemed to compile okay, then had a bunch of timed out errors when uploading.

Maybe I am missing a step that should be obvious? Will look further tomorrow, thanks for the help so far

I just tried uploading an example sketch using arduino (found in File>examples>stepper>stepper_oneRevolution) to see if the board would be responsive, it compiled and uploaded but board now has one red light solid, one blinking. In addition I have a strange sound coming from my power source going on and off with the light... Is there any way to reset the ramps board? The physical reset button doesn't do it...

I don't know any way to disable the physical rest on the Arduino, it has always worked for me. You can always unplug and reconnect the USB cable, that too will reset it (the Arduino gets its power via US. It sounds like you are able to push code to it, and when you do an upload it will also reset the board and install new code, so an equally valid thing to do now is just push Marlin to it. Then, back in the Serial Monitor, hit enter. You should get an 'ok' and a bunch of echo statements.

Also, you don't need to hook up your external power supply until/unless you have firmware installed and recognizable on the board. It's possible that the sample code you pushed has redefined the pins, so I would definitely unplug anything except the USB until you've gotten the firmware installed sucessfully.

I've heard of other people having timeout issues, my understanding is that repetition usually succeeds.

Alright! I compiled and uploaded Marlin without a problem this time, after unhooking the reprap and power source. This is what is coming out of my Serial Monitor. Any ideas? Also, I connected successfully to pronterface, but it spits out this same error.


start
echo: External Reset
Marlin: 1.0.0 RC2
echo: Last Updated: 2012-02-25 | Author: erik
echo: Free Memory: 5625 PlannerBufferBytes: 1232
echo:Using Default settings:
Error:
: Extruder switched off. MAXTEMP triggered !
Errorrinter stopped deu to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)



EDIT:
In another thread it was mentioned that this could possibly be caused by the thermistor. This would explain why the serial monitor and pronterface think my hot end is 481ºC. I have what I believe to be the thermistor plugged into T0, it is a set of black and white wires running into the extruder. Maybe I would know more about this if I were the one that assembled it.. :/ Is it possible that the thermistor is shot, or maybe just plugged into the wrong pins?

Edited 1 time(s). Last edit at 04/10/2012 09:10PM by xkylewrightx.

This is progress. T0 is the correct set of pins for the thermistor. What other wires come out of your extruder? What kind of hot end do you have? Photos will help. You should have a thermistor and a heating element of some sort. I would have expected the heating element to be bare wires for plugging into D10, and usually the thermistor wires are much thinner because they don't carry nearly as much current as the heating element.

Alright! After testing the thermistor with a multimeter and finding it to be okay, I found that the thermistor has to be defined in Marlin. Switched marlin to the 100k thermistor and no more error message! Motors seem to work, and printer heats up to well over the desired heat. Now on to calibrating...

I have this program (on my windows computer) found here...

[www.makerbot.com]

Is this helpful to me?
Im not sure where to input the values.. Marlin?
Where can I set the home location of the extruder and build plate? Pronterface?

Thanks for the help!!

Excellent!! You're now in the home stretch, where all the real fun begins - you will soon be CREATING THINGS!

Since you have Pronterface and Slic3r, I suggest you immediately browse to [richrap.blogspot.com] - he has done a truly excellent job walking you thru the calibration and introduction to Slic3r, much better than I could do here. That's just part one of his series on Slic3r, be sure to read parts 2 and 3 as well. part 2 is critical to you, part 3 is more advanced but will give you an idea of what to aspire to.

Find some calibration objects (search for "calibration") on [thingiverse.com] - I suggest a 40mm by 40mm cube to begin with, then the more advanced ones that exercise bridging and towers and the like. Once you think you have dialed in the printer acceptably, it's traditional to print yourself a shot glass and have a toast to success.

Be sure to update this thread with your progress!

This is a great link for calibrating the printer, however I think I need to "home" the head and build plate first. It doesn't seem to know where it is, as when controlling the x, y, and z movement from inside the GUI of pronterface, it will stop before reaching the end in one direction and hit the end of the track in the other. It doesn't know what position is 0. Where can I set this?

Also- (after heating to 185 of course) I will try to extrude pla from the extruder using the GUI in pronterface, and the motor makes weird sounds and doesnt move the gears. Is there a way to calibrate/set/etc the extruder that I am missing?


EDIT: Can you tell me about the "position of the homing switches" setting in Marlin (or sprinter)? Is this what I am looking for?

Edited 1 time(s). Last edit at 04/12/2012 06:53PM by xkylewrightx.

Oh boy. Where to start. There are mechanical endstops and optical endstops (there are other types such as magnetic, too, but unlikely you got those as part of a kit). Which do you have? Do they look like switches that make a distinct click when you depress the lever, or do they look like plastic legs that an opaque flag would slide between and obstruct the light beam?

Yes, you need to inform Marlin which type and where they are located. The RAMPS boards have connectors for minimum and maximum in all three axes, but most people only ever install endstops for the minimum (the home position) in each axis. Depending on which version of Marlin you have, that will be in the configuration.h file or if you have a newer version (I think you said you did) then there is a basic and an advanced config file. I assume it will be in the basic file.

Look for a section titled something like "mechanical settings". If you are using optical endstops from Mendel-Parts like the ones I use, there are three lines saying (or should be edited to say) "const bool something_ENDSTOPS_INVERTING = false". Further down there should be lines that define the direction of endstops when homing, make sure those are all set to -1. There are also some lines that define the software endstops, if uncommented then the printer will stop when it is homing and hits the zero endstop in any axis, and won't advance to coordinates beyond the maximum defined right below that. For example, my line "#define X_MAX_LENGTH 182" tells my printer that once it knows where the X 0 position is, to not move beyond 182 in that axis. Most Mendel variants will have X and Y maximums of around 200mm, and Z depends on the height of your print bed, whether it has an extra plate of glass on top, and the type and orientation of your extruder. My Z max is set to 150.

After you get Marlin set up, you then need to get the motors moving in the right direction and adjust the physical endstops so they are accurate. I fabricated my first set of optical flags out of cut up pieces of tuna can and blue painters tape. Your X and Y endstops should be set so that the print head gets as close to the appropriate edge of the print bed as possible without interfering with anything on the print bed like raised screw heads, bulldog clips or whatever. Your Z endstop should allow the nozzle to get close enough to the print bed that you can barely slide a piece of paper beneath it.

If your motors make funny noises and don't behave as expected then you may have the current set wrong on the stepper drivers or you may be trying to move them too fast, or both. In Pronterface, for manual movements, set your extrude distance to something low like 5mm, and the speed (it's next to the reverse button) to something like 50mm/min. Also in Pronterface, set your XY movement to something like 6000mm/min and Z to a low value like 150. Now, on the RAMPS board, on each pololu stepper daughter board there is a small potentiometer. Turn this all the way counterclockwise, then back 1/8 clockwise. Try to move a motor in Pronterface and slowly increase the pot clockwise until you get smooth movement. You want these set as low as possible so that your motors don't get too hot while still giving enough current that the motors move smoothly. Also check [reprap.org] for the wiring to ensure your motors are wired up properly.

Hopefully this will get you farther along.