Ground connections for L293D

Hello again,

Nowadays, I am designing a stepper motor controler for usunig with arduino. I have a L293D H-Bridge and a 4wire stepper motor. Datasheet is here

I want to use arduino for PWM and I found some projects on internet such as:
https://raawbot.wordpress.com/2009/10/28/motor-control-with-arduino-and-l293/

But in this example project they used the same ground for both logic input and motor supply. I checked the datasheet by myself but it was quite complicated to decide....

Does anyone has an idea which ground pin is for logic and which is for motor suply?

Regards,
Özgür

hi,
For the logic input signals to control the L293 there must be a common ground [0v] for both the logic and the motor supply.

ericgibbs said:

hi,
For the logic input signals to control the L293 there must be a common ground [0v] for both the logic and the motor supply.

Click to expand...

Hi Eric and thanks for your answer.

Let me double check what I understood from your answer. I will connect the GND or (the negative pole) of logic supply voltage source to the negative pole of the motor power supply together with GND pins of L293D. Am I correct?

I am not an electronic engineer, that's why i can confuse myself with basics easily...

ozgur84 said:

Hi Eric and thanks for your answer.

Let me double check what I understood from your answer. I will connect the GND or (the negative pole) of logic supply voltage source to the negative pole of the motor power supply together with GND pins of L293D. Am I correct?

I am not an electronic engineer, that's why i can confuse myself with basics easily...

Click to expand...

hi,
Look at this image for the LM293D

Actually there is not a negative/minus supply on this LM293, the neg/minus of the power supply is referred to as 0V or Ground.

ericgibbs said:

hi,
Look at this image for the LM293D

Actually there is not a negative/minus supply on this LM293, the neg/minus of the power supply is referred to as 0V or Ground.

Click to expand...

Thanks a lot! This was a perfect reply! Now I am sure about the connections. Thanks!