Arduino Mega 2560 + Ramps 1.4 + ATX Power +5v and +12v

Hello Reprappers.

I am very happy starting my first 3D printer project with Arduino (i3).
But now I have one question with power supply... And I dont want leard burning my first arduino.

I do not know how to explain what I want do, but I create an image that will demonstrate the system..
I will use LCD and SD module to stand alone operation

My questions:
1 - The Arduino and Ramps will work without USB connected? I will have problems?
2 - What will happen when I connect USB with ATX +5v in same time? Burn all?

You do not need to connect power to your arduino board it will be powered from the ramps or if that's disconnected from the 5v of the usb port.

Ben

Thank you Ben.

So.. If i'm printing with SD Card (Gcode) and with USB plugged, when I unplug the USD the printing will still normal?

I dont need plug +5v with red and gnd showed in my picture?

Edited 2 time(s). Last edit at 11/10/2015 02:51PM by engmaster.

If you are using a lcd add on so you can select the files to print I don't see a problem but I would disconnect the usb first and then start the print from the sd card.

Ben

When I first started printing from SD card, I found that my Arduino Mega would reset mid-print if I was connected to the PC, and then pulled the USB cable while the SD Print job was under-way.

I now do all of my "production" printing stand-alone using the SD Card on the LCD Smart Graphics Controller. While calibrating / tinkering with my printer's firmware etc, I drive it from Pronterface on the PC. I don't ever disconnect the USB cable from the printer mid-print any more.

My RepRap is powered from a 12 volt power supply, which powers the RAMPS and the Arduino Mega (no 5 volt power supply). When I am connected by USB to the computer, the printer will boot up and the LCD will shows it's status even if I don't power up the 12 volt supply (e.g. it will show me the temperature of the heat bed and extruder hot-end), but the USB can't drive any of the motors or heaters etc.

(Recent updates to Marlin firmware and / or Pronterface might have eliminated the Arduino reset issue, but I had enough failed prints early on to not want to go back to experiment again!)

Edited 1 time(s). Last edit at 11/10/2015 10:33PM by julianh72.

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Follow my Mendel Prusa build here: [julianh72.blogspot.com]

The voltage regulator on the Arduino will typically overheat if you connect a graphical LCD to it and you don't provide external 5V power either via the USB cable.or directly. This in turn can result in the bed mosfet overheating or the Arduino resetting.

There are workarounds such as driving the LCD backlight from 12V through a series resistor instead of from 5V, but my advice is not to use Arduino/RAMPS. There are several low cost 32 bit controllers available now.

Edited 1 time(s). Last edit at 11/11/2015 10:28AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Ok. Thank you guys.

I will use only +12v plugged in my ramps.

My first print will be with USB plugged and I dont will unplug the USB whiling printing.. So.. after I will test without USB.

Thank you again!

Hi guys,

Beware your PC PSU delivers enough power on the 12V port.
Check the label or measure with a mutlimeter.
You will probably need at last 15A.

++JM