Ramps 1.4 & Arduino power source

Hi Guys

I have installed a RepRap discount full graphics controller onto my Ramps 1.4 & printing, however when I remove the USB cable from the Arduino, my printer stops.
What have I done wrong that I have to still have the USB cable from the PC to keep it it powered ?

I have a bought power supply of 29amps ( Silver one ), NOT a PC power supply.

Please let me know what I have probably done wrong.

Thanks
Mendel90

As far as I know you have to give your RAMPS board a seperate power connection or solder some diodes. Details can be found in the wiki: [www.reprap.org]
The relevant quote:

Quote
Reprap Wiki
Without D1 installed, or when the 12VIN is not connected, the Arduino gets its power from USB. If you want your kit powered without USB connected you need to solder in D1 OR connect VCC to your PSU.

Disclaimer: I just read about this some time ago but actually never implemented it in my build, as of yet.

One of the problems with Arduino/RAMPS is that the 5V regulator on the Arduino Mega can barely provide enough additional power to drive the backlight on a LCD display. Sounds like the backlight has pushed it over the edge in your case. Possible solutions include:

1. Supply the Arduino/RAMPS with a separate 5V supply. Easy enough when using an ATX PSU, but if you are using a 12V LED PSU then this means using a separate 5V regulator.

2. Use an Arduino variant with a higher power voltage regulator, e.g. Taurino.

3. Disconnect the LCD backlight anode from the +5V supply, and run it instead from 12V through a series resistor. A 180 ohm 0.5W resistor should be about right.

Similar considerations apply if you try to power a servo from +5V - the Arduino regulator can't cope.

Edited 1 time(s). Last edit at 07/21/2015 07:27AM 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].

Hi Guys
So guys I can supply 5volts to the Arduino and it will be ok ? . I have a small power supply that you can set to 5 volts, I plug that into the Arduino board.

Thanks

I have exactly the same problem with my LCD controller. I have been printing Repetier Host on my laptop for about 6 months but recently tried to implement the SD card method. I am very new to electronic hobbies so I need some of the explanations clarified (ie: dumbed down).

My system:

Arduino Mega 2560 R3
RAMPS 1.4
ATX 230W power supply
Rep Rap Full Graphics LCD Controller
Repetier Firmware
Repetier Host

With the USB cable attached to the laptop the LCD screen functions properly, with or without the ATX power supply turned on.

To operate the extruder heater and print, I need to turn on the power supply (obviously).

I can print with this arrangement using the SD card and controlling the printer fully from the LCD encoder, even without Repetier Host running on the laptop.

But it MUST be connected to the laptop with the USB cable. Disconnecting the cable results in the LCD going black and the print stopping.


So it seems that the Arduino is not supplying the required 5V to the LCD (by way of the RAMPS breakout board), even if the12V power supply to the RAMPS is operating?

How do you connect another 5V supply directly to the Arduno? There is an unused 12V barrel connector on the Arduino but would connecting a 5V wire from the ATX work there? I don't want to try this and find I've fried my board!

Thanks

All arduino mega Can handle 12v input as Well.
Split the 12v power going to ramps and find a barrel-connector that fits into the arduino Board.
If you have a seperate 5v source, then you Can use that instead. Using 5v input Will put less stress on the arduino converter that supplies 5v to certain Ramps 5v outputs. I have been running wih 12v for a year without issues though.

Edited 1 time(s). Last edit at 09/11/2015 03:23PM by dintid.

Nearly all the power taken by the LCD is used for the backlight. So an alternative is to modify the LCD to drive the backlight through a series resistor from 12v, instead of from the 5V supply.

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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].

Excellent!

Thank you

Check if diode D1 is there on Ramps and mounted in the right direction. #see attached pic
Then you should check if arduinos 5V regulator is working before you can even think of doing any mods to Ramps or LCD.

Don´t feed 5V to arduinos barrel connector as proposed before. The regulator needs at least 7V input voltage to work properly. With only 5V input the risk of overheating MOSFET is bigger.
-Olaf

I didn't pull off the motor drivers to check, but from web image searches it appears the the "red" RAMPS 1.4 boards have the D1 in place while the "green" boards (which I have) do not.

This seems strange to have the ability to operate completely stand-alone but neglect to include one little part that allows it to happen. An oversight?

At any rate, I will connect 12V to the barrel connector. If it shortens the board's lifetime I will likely upgrade to another type (Smoothie?) anyway.

Thanks for the info and cautions.

Regards

Mine runs fine on 5v AND when using 12v to ONE of my boards, it fails to output 5v on AUX connections. Sounds like 7v is a good idea, but that is a hard voltage to hit for normal people (normal = non-electronical minded that can't come up with some stuff to magically get 12v to be 7v )

Edited 2 time(s). Last edit at 09/12/2015 10:53AM by dintid.

Quote
o_lampe
Check if diode D1 is there on Ramps and mounted in the right direction. #see attached pic
Then you should check if arduinos 5V regulator is working before you can even think of doing any mods to Ramps or LCD.

Don´t feed 5V to arduinos barrel connector as proposed before. The regulator needs at least 7V input voltage to work properly. With only 5V input the risk of overheating MOSFET is bigger.
-Olaf

As I said above, mine runs fines on 5v, but I wasn't aware of any overheating of Mosfets... what mosfet is that? - Not being sarcastic or anything, but I genuinly would like to know what mosfets? On Ramps or Arduino, and WHY would it overheat?

I Have read lots of warnings about using 12v on Arduino as it would overheat due to the conversion to 5v needed. Guess I'll tune mine to 7v maybe

Edit: I know, and have read about, a lot of people, running their Ardunio Mega only through USB power, which is 5v - without any probllems... does the Mosfet overheating only pertain to 5v through the Barrel-plug, or?

Edited 4 time(s). Last edit at 09/12/2015 11:07AM by dintid.

OK I chickened out on connecting the 12V to the Arduino barrel jack. Instead I pulled the stepper drivers off to see if the D1 diode was in place.

And...it is. It seems to be placed correctly with the band on the left end (the end of the Arduino with the USB connector)

I powered on the Arduino/RAMPS and checked across D1 with a multimeter (couldn't run the steppers with the drivers off). Got a reading of 0.59V with the positive on the right. Is it supposed to be that low?

So my understanding is that if this D1 is in place, turned the correct way around and functioning, then I should be able to operate the Smart Controller without the USB cable plugged in. Is that correct?

On other thing I noted (since problems with the LCD seem to be related to the amount of current the back-light draws)...with the Arduino/RAMPS powered only with the USB cable the backlight is on continuously (white letters on blue background). When I switch on the PSU, the backlight goes out (dark letters on light blue background ...harder to read) . And when I pull the USB cable, even with the PSU still on, the LCD goes completely dead.

If I want to connect 5V (or 12V) to the Arduino barrel jack from the PSU then I must first remove the D1?

I'm hoping I can get clarification on this issue. It seems to come up from time-to-time in other threads but I've never read a complete resolution to it. Any explanations I read end up drowning me in acronyms and alpha-bet soup.

Thanks.

Edited 1 time(s). Last edit at 09/15/2015 04:28PM by 2YRRAH.

Hello 2YRRAH
You can safely connect 12v to Arduino Barrel regardless of wheter you have D1 in place or not. Same goes for USB.

D1 Works by powering the Arduino through the Ramps, so you should not need barrel or usb if D1 is in place AND you feed enough 12v amperage through the 12v 5amp connector on the Ramps? If the power-source through ramps is too weak (or you have some faults on ramps, or maybe arduino) you might need the direct power into the Arduino.

I just got confirmed that 5v to the Barrel-jack is too low - recommended is between 7-12v. I got confused on this, as USB is 5v, but it's apparantly working differently inside.

I have removed my D1 on the board I have in front of me, as I run 24v into it, which I do not want to go Down into the Arduino, so can't measure the D1.

Edited 2 time(s). Last edit at 09/15/2015 04:47PM by dintid.