0
\$\begingroup\$

I'm pretty new to electronics. I'm using an Adafruit ESP8266 microcontroller connected to a L293D motor driver to power a bipolar stepper motor. I'm struggling to understand the various voltage levels throughout the circuit. For example, the datasheet for the L293D has a supply voltage VCC1 ranging from 4.5V to 7V. However the high-level input voltage has a minimum voltage for a logical true of 2.3V. The microcontroller can supply 3.3V. So does that mean i can connect the microcontroller to the L293D, but i would need some other voltage supply connected to the L293D as well that would be in the range of the supply voltage?

Also, the motor requires 12V to run. How do i control the output voltage on the L293D? Do i need to use a voltage regulator or level shifter on the output? Thanks

\$\endgroup\$
0
\$\begingroup\$

How do i control the output voltage on the L293D? Do i need to use a voltage regulator or level shifter on the output?

You will need to provide 5 volts and 12 volt supplies to the L293D in order to activate 12 volt motors: -

enter image description here

It will operate with 3.3 volt logic inputs but the 5 volt supply should not be lower than 4.5 volts as per the data sheet.

You do not need a level shifter on the output because of the 12 volt feed to the chip. See also this post on some of the problems associated with L293 chips especially when using low voltage motors.

\$\endgroup\$
  • \$\begingroup\$ Thanks for the quick reply. Apologies if this is a silly question but how do I connect the supply? Can I use a battery or is there a component I can use? \$\endgroup\$ – Yogi12 Feb 22 '18 at 15:07
  • \$\begingroup\$ You can use a wall wart that outs 12 volts and a regulator to make 5 volts from the 12 volts. You also need a supply for your ESP8266. \$\endgroup\$ – Andy aka Feb 22 '18 at 16:26
  • \$\begingroup\$ It looks like the OP is trying to control a bipolar step motor...not a DC motor. \$\endgroup\$ – whitegreg56 Feb 22 '18 at 22:12
  • \$\begingroup\$ @whitegreg56 you are missing the point of his question. Motor or stepper, it’s irrelevant really. \$\endgroup\$ – Andy aka Feb 22 '18 at 22:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.