Two Drv8825 motor driver to run a single stepper motor

Hi , is it possible to connect two drv8825 drivers to a single (Nema 17) stepper motor . Each Drv8825 is connected two different controller, but they share the same stepper motor ( A1 , A2 , B1 , B2 of the both drivers are shorted and given to motor pins ) . Is it possible for one Drv8825 to run the stepper motor without harming the other driver . For example ,enabling one driver and disabling the other one . So that the motor is driven by the enabled driver and the current doesn't flow into the disabled driver .

I can't use just one drv8825 because the code is cumbersome ( 3d printer ) and for simplicity sake I am using an arduino uno as a secondary controller to move the stepper motor with a accelstepper library.

If it is not possible is there any other way to achieve this , adding some kind of switches like relays or mosfets to the A1 A2 and b1 b2 pins of the drv8225 and the stepper motor.

Thanks in advance.

I reckon one of the drivers would be destroyed.

If you want useful help you need to explain what you want to achieve rather than presenting what you think might be a solution.

It would be possible to use external components to route the signals from two MCUs to a single driver - though I can't imagine what you want to do that would need more than one MCU.

...R

Robin2:
I reckon one of the drivers would be destroyed.

If you want useful help you need to explain what you want to achieve rather than presenting what you think might be a solution.

I am trying to move the Z axis stepper motors on my 3D printer for now. This can be done using the on board drv8225 . But I am trying to use a secondary controller that can move the z axis stepper motors to add new functionality to my 3D printer. The secondary controller has it's own drv8225 driver that can move the Z axis stepper motors when a command is given to the printer . The problem i am facing is that I am not sure how to switch between 3D printer Drivers and the secondary controller drivers.

It would be possible to use external components to route the signals from two MCUs to a single driver - though I can't imagine what you want to do that would need more than one MCU.

Yes I know it is possible using my 3D printer's MCU , but i want to use a secondary MCU for simplicity sake and also to reduce the processing burden on the 3D printer's MCU .

Duinuoar:
but i want to use a secondary MCU for simplicity sake and also to reduce the processing burden on the 3D printer's MCU .

In theory the solution to that is to build an external circuit that allows both MCUs to control the same driver without interfering with each other. And, in theory, that is not too difficult assuming only one MCU will be active at any one time.

Where practice rears its ugly head is that you would need to remove the DRV8825 modules from 3D the printer system and mount them on a PCB that you make, and then build connections from the 3D printer system to your new PCB.

But I still don't understand what exactly you want to do that requires a second MCU. Can't you just create a suitable GCode file that can be fed to the 3D printer to do whatever you need?

...R

Duinuoar:
Hi , is it possible to connect two drv8825 drivers to a single (Nema 17) stepper motor . Each Drv8825 is connected two different controller, but they share the same stepper motor ( A1 , A2 , B1 , B2 of the both drivers are shorted and given to motor pins ) . Is it possible for one Drv8825 to run the stepper motor without harming the other driver . For example ,enabling one driver and disabling the other one . So that the motor is driven by the enabled driver and the current doesn't flow into the disabled driver .

I can't use just one drv8825 because the code is cumbersome ( 3d printer ) and for simplicity sake I am using an arduino uno as a secondary controller to move the stepper motor with a accelstepper library.

If it is not possible is there any other way to achieve this , adding some kind of switches like relays or mosfets to the A1 A2 and b1 b2 pins of the drv8225 and the stepper motor.

Thanks in advance.

What 3D printer design are you using?
Gantry, Delta, etc.
http://reprap.org/

What is it you are attempting to do?

I have built several CNC machines and I do not understand the purpose of the two drivers for a single stepper motor in the Z axis.

Duinuoar:
Hi , is it possible to connect two drv8825 drivers to a single (Nema 17) stepper motor . Each Drv8825 is connected two different controller, but they share the same stepper motor ( A1 , A2 , B1 , B2 of the both drivers are shorted and given to motor pins ) . Is it possible for one Drv8825 to run the stepper motor without harming the other driver . For example ,enabling one driver and disabling the other one . So that the motor is driven by the enabled driver and the current doesn't flow into the disabled driver .

I can't use just one drv8825 because the code is cumbersome ( 3d printer ) and for simplicity sake I am using an arduino uno as a secondary controller to move the stepper motor with a accelstepper library.

If it is not possible is there any other way to achieve this , adding some kind of switches like relays or mosfets to the A1 A2 and b1 b2 pins of the drv8225 and the stepper motor.

Thanks in advance.

You aren't really thinking this through clearly. You control the motor driver with step and direction signals, so you just need a way to temperarily override these control signals.

Trying to interface at the high power side is fraught with many issues that could destroy hardware. You wouldn't implement a dual-control car with duplicate engines and brakes would you? Same idea, do all the control on the control side.