Ramps 1.4, mega2560 problems

Looks to me like you’re trying to measure the amperage directly, based on the meter connections and setting I see in the pic. You want set the current by measuring and setting Vref with voltage connections and settings on your meter.

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Great catch!

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Okay so, originally I was using a meter that only had a 300 volt dc setting to set vref and was only getting a 1 or 2 voltage reading…

Fast forward I’ve got a proper meter and set the vref to .9v (my stepper motors are rated for 2 amps). I’m not able to move the steppers at all… could I have possibly fried my steppers or am I needing to home the steppers or change something on the lcd menu?

Since the stepper motor is mounting to PLA plastic with a low melting point, it is the temperature of the stepper motor which is the limiting factor to current, not the amount of current the stepper motor can handle. At 0.9v, watch your stepper temperature carefully to start…or back down your current to start and nudge it up if you need more torque.

could I have possibly fried my steppers

Stepper motors are simple devices and are really hard to damage. In the hundreds of topics where the OP asks whether he has damaged his stepper, I’ve only seen two dead stepper motors…and that was individual motors, not all the stepper motors on a machine. At this point, I’d assume your steppers are fine. It is possible you damaged your stepper drivers, but I would not go there yet either.

The first thing is to make sure you are communicating with Marlin. How have you tried to move your steppers? Repetie-Host? Display? If Repetier-Host or some other g-code sender, are you sure you are connected and is the board responding?

If you are communicating okay, then my next concern would be the fuses on the Ramps 1.4 board.

Im using a brand new set of 8825 drivers, mega 2560 , and ramps 1.4 just assembled as of my last test and I’m using the lcd to jog the x and y axis.

I have a ramps and am fairly certain .7 is the recommended setting

Using the display eliminates communication as a potential issue. That leaves 1) 12V power is not getting to the motors, so probably a fuse issue, 2) you have the steppers wired wrong wrt the plugs on control board, or 3) maybe bad power supply.

And, do you have the firmware setup for DRV8825 drivers?

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I did not edit anything in the firmware. I was having an issue with platformIO not allowing me the function to compile so I just used XLoader. If I can figure out platformIO, do I just use the find command and enable the drivers?

Also I want to mention that I do get the slightest twitch from the steppers when sending the command to move (not even a little bit close to the 10mm selected). Each axis will twitch one time and then no more.

The stock firmware is set up for DRV8825 drivers, so you don’t need to make any changes. I saw you mention A4988 drivers above and thought you might have made some changes that you would need to revert.

A slight twitch indicates the fuses are not the root of the issue. Power supply is still a possibility, so if you have an alternate 12V supply, you might try it.

You should check the wiring of the stepper. Here is the pinout for the DRV8825:

image

Note how B1/B2 have pins next to each other, and A1/A2 are also next to each other. A vs B does not matter, but each coil should be wired with adjacent pairs. In your stepper motor, B1/B2 should go to both ends of one of the coils. A1/A2 should go to both ends of the second coil. You can put your multimeter in ohm mode and check the adjacent pin pairs in the connector of your stepper motor to verify the coil wiring.

Note that if only one of your two coil pairs is connected, you would get a single twitch. As a side note, since you noticed the twitch, I wanted to make sure you have all the jumpers installed under each of the stepper drivers. The jumpers are not the root of your issue, but the lack of jumpers would make the twitch much larger, and for the Primo, you want the jumpers installed.

Okay so it does look like I’ll need to switch the pin arrangement.

No, my mistake. While the driver is wired as I specified, the pinout for the Ramps 1.4 is as follows:

image

This matches your diagram from Stepperonline. Sorry for the misinformation. You still want to check the cable to make sure you have connection across each coil. You might also examine the soldering of the stepper sockets. The only thing I can think of that matches your behavior is that you are only powering one coil.

I swapped the red and black wire at the stepper to board plug and things seem to be working, the steppers are now rotating!

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