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I am using L298n Dual Motor Controller to control two dc motors for my robot. But I want it to power the servos too. I have created this circuit design. enter image description here

can I power the SG90 Servo with L298n? Is there any fault in the circuit? Any Other suggestion will be appreciated.

Specifications of components:

DC Motor -

  • Voltage range: 6-9V
  • Motor speed: 188RPM
  • Reduction ratio 45:1

Servos -

  • Torque 25.0 oz-in (1.80 kg-cm) at 4.8V
  • Voltage 4.0V to 7.2V, 4.6V - 5.2V nominal
  • Running current with 5V supply (no mechanical load) 220 ±50mA
  • Stall current with 5V supply (horn locked) 650 ±80mA
  • Idle current with 5V supply 6 ±10mA

Battery - 7.4v Lithium Ion Battery 2600Mah

Motor Controller - L298n

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  • What does this have to do with the Pi?
    – Milliways
    Feb 1, 2017 at 7:41
  • I am using pi to control everything. I am using Pi instead of Arduino is because I am adding many features to my robot car, including voice assistant and much more.
    – Anshul Bansal
    Feb 1, 2017 at 7:44
  • I am trying something similiar with lego motors. I voted this question up. Can you please post your results. What I usually see with motor shields, is that the servo is connected directly to the shield. So this would be an inexpensive alternative.
    – Stowoda
    Feb 2, 2017 at 12:20
  • This is not a question, it's a review request.
    – Dmitry Grigoryev
    Feb 7, 2017 at 15:11
  • @AnshulBansal did you get this one to work? I have a similar setup but I have problems with servo jittering when running the motors.
    – birgersp
    Oct 29, 2020 at 9:05

2 Answers 2

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That will be fine.

Servos and DC motors are quite power hungry so don't expect the battery to last very long.

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According to this the power required for the servo is around 200mA (but yours may be a different module, check the current requirements for your own model).

So with 2 of them you'd need the L298 Motor driver modules' onboard 5V to be able to provide 400mA.

Depending on the module it could be providing anything from 50mA to > 1A - check with regulator it uses and find the current it can provide.

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  • Will the 7.4v battery provide enough volts for all four motors (4.8v-6v servo and 6-9v dc motor)?
    – Anshul Bansal
    Feb 1, 2017 at 9:56
  • Yes. It is not volts you need to be concerned with here, it is current (Amps / milliamps)
    – KennetRunner
    Feb 1, 2017 at 10:04
  • You might want to post datasheets for the motors, batteries and H bridge module you are using, as there are so many variations it's tough to say definitively... and this question is really more suited to electronics.stackexchange.com
    – KennetRunner
    Feb 1, 2017 at 10:15

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