I'm new on this so this is probably a very simple question but I could not find the answer.
I'm making a bipolar stepper driver with a L293D IC. OK ir works as expected, but I discovered something that cannot understand.
I'm powering the motor with a power supply (+5V) to pin 8 of the L293D. And the IC itself with the +5V of the arduino (to pin 16).
The code in the arduino make the motor rotate continuously. But, if I unplug the power supply for the motor, it still rotates! Why? I suppose that if there is no voltage in pin 8 (Vs) it uses the voltage in the pin 16 (Vss). In that case this is something not to do, I suppose...
So if I want to switch off the motors I should disconnect the 5V in the pin 16 (the logic part). Or better bring low the enable signals.
What is correct?
Thanks for your help.