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Arduino Mega 2560 + CNC Shield + GRBL

Posted: Tue Jun 14, 2016 2:28 pm
by AWS
Hello,

First of all I would like to say that I am relatively new to whole this thing with stepper motors and cnc machines so please do not be mad if I ask some odd questions :)

I have the following configuration:

1. Aurdino Mega 2560
2. CNC Shield V3.00
3. DRV8825 Stepper Motor Driver Carrier, High Current
4. Stepper motor - Sanyo Denki 103-547-52500
5. Power supply - 12V DC, 3.0A 36W Max

When I use this hardware that I have with original Arduino software (and AccelStepper-1.51 Library) I am able to move all motors (on every axes - X,Y,Z).

But When I try to use UniversalGcodeSender for GRBL in order to manually move the motors I am not able to move them at all. I know that there is an compatibility issue with GRBL and Arduino Mega. But I read somewhere that there is still possibility to make them work although I was not able to find somewhere some step by step instructions...

I have managed to find this site: http://zapmaker.org/arduino/programming ... -mega2560/
and by following the instructions there and installing the grbl file Grbl9fMega2560 on Arduino Mega (from this site: https://github.com/LETARTARE/Grbl-xx_with_Arduino) I was only able to get buzzing noise from my motors, but when I try to move them (with Grbl Controller or UniversalGcodeSender) I get nothing. Not a single movement.

I hope that someone can help me with this issue or at least give me a lead to somewhere where I could be able to manually move my motors.

I would like to thank you all in advance on your help :)

Re: Arduino Mega 2560 + CNC Shield + GRBL

Posted: Wed Jun 15, 2016 4:07 am
by Bertus Kruger
Sounds like you are on the right track.

Buzzing motors to me sound like you have enabled the stepper drivers.

The issue will be that the step and direction pins are not set to work with the CNC shield. From memory the Mega's pins are not setup the same as the Uno.

I am not sure if anyone has tried changing the Pin map for the MEga to work with the CNC shield yet.

I have a custom Mega board on its way will likely test this in the next week or so.

Re: Arduino Mega 2560 + CNC Shield + GRBL

Posted: Tue Nov 17, 2020 3:32 pm
by 3runo
The thing is, arduino mega grbl isn't pinout compatible with arduino uno pinout - so regular CNC shield v3 will not work

Image

Image

You have to modify the pinout in source code and turn off what you don't have to prevent conflicts. I suppose from here will be easier as regular version now has 6 axis and there will be more things to disable

Re: Arduino Mega 2560 + CNC Shield + GRBL

Posted: Fri Aug 27, 2021 11:21 am
by Erikcramerjr
Could you say when you expect the board to be out?
Did all tests go well, and will it support the extra motors?

Bertus Kruger wrote:
Wed Jun 15, 2016 4:07 am
Sounds like you are on the right track.

Buzzing motors to me sound like you have enabled the stepper drivers.

The issue will be that the step and direction pins are not set to work with the CNC shield. From memory the Mega's pins are not setup the same as the Uno.

I am not sure if anyone has tried changing the Pin map for the MEga to work with the CNC shield yet.

I have a custom Mega board on its way will likely test this in the next week or so.