Stepper Motor Enable line

[dhinesh.ganesan]

Hi there

I am using DRV8834 IC driver to run the 5v stepper motor. I've managed to run the 5v stepper motor using DRV8834 IC. But I've found we need 3 pins (Step, Direction and enable) to enable the device.

The requirement is to reduce the pins to 2 (only for step and direction). If I don't use the enable pin then the driver and motor consume tiny power. Is there any idea you can help me with to use any MOSFET/any other idea/pulse stretcher to control the power consumption without using the enable pin? Please let me know if you guys got an idea. Your help is much appreciated.

Thanks in advance.

 

[kellys_eye]

The enable line is used to switch the motor drive outputs on/off and if the chip is 'disabled' you won't have any coil current i.e holding torque - if that's an issue for you. If not then tie it high/low accordingly.

If power consumption is not a real issue you could use a retriggerable monostable triggered by the clock/direction to enable the device.

 

[dhinesh.ganesan]

The enable line is used to switch the motor drive outputs on/off and if the chip is 'disabled' you won't have any coil current i.e holding torque - if that's an issue for you. If not then tie it high/low accordingly.

If power consumption is not a real issue you could use a retriggerable monostable triggered by the clock/direction to enable the device.

Thanks for your help.

Holding torque not an issue for me now. As I have understood that using a monostable 555 timer IC will send a pulse to enable the device via the direction pin? Am I right?

 

[kellys_eye]

As I have understood that using a monostable 555 timer IC will send a pulse to enable the device via the direction pin? Am I right?

No.

If you don't want to use the enable pin you can either wire it directly to the appropriate logic level to 'fix' it status OR if you want the enable pin to function 'properly' you could fix the output of a monostable to the enable pin. The (retriggerable) monostable input would be from the clock/direction signals such that on any occurrence of either a step or direction pulse, the enable line is activated.

As soon as the clock/direction (i.e. movement command) is stopped then the enable line will revert to its original 'off' state.

 

[dhinesh.ganesan]

I got it and thanks for your help