L239D Not able to power 2 motors at the same time

[LinuxNinja99]

Hi,
I'm trying to use an L239D H-Bridge motor driver but I'm only able to control one motor at a time.
The motors and the controllers aren't defective.
If I unplug one motor the other one spins.
The motors are those common 3-12V dc motors.
My power source is a 9V Battery.
The motors seem to be running at only 3V.
The motors draw around 200mA @ 3V
The L239D Is from an Arduino Starter Kit (From arduino.cc)
Circuit + code: https://mechatrofice.com/arduino/l293d-motor-driver (I didn't write the code)

[Paul_KD7HB]

A common problem when people use smoke alarm batteries to power motors. Use AA cells in series to get 12 volts or so and try that.
Paul

[LinuxNinja99]

Still seem to have the same problem.
I'm powering it with my lab bench power supply.
At least they run at 9V now.

[LinuxNinja99]

I fixed it by powering it from my power supply at 6 volts.
The dropout of the arduino Vin regulator caused some problems when powering it with 5 volts

[TomGeorge]

@LinuxNinja99

I seemed to have fixed it by powering it with 5V

Can you please post a circuit diagram of your project please?
Include power supply and pin names/labels.

Thanks.. Tom..

[LinuxNinja99]

The circuit diagram and code is in this link: (scroll down a bit) https://mechatrofice.com/arduino/l293d-motor-driver
The power supply is a Lab Bench Power Supply @ 5V

[LinuxNinja99]

I have to re-upload the code every couple times of starting it up.
The Arduino's L led just blinks and the motor's start up is very inconsistent
It works better when you supply it with 7v

[TomGeorge]

Hi,
@LinuxNinja99 reference circuit;

Now can I suggest you draw your circuit, reverse engineer your project.

I hope you have the USB connected while doing these tests or at least a 5V supply between gnd and 5V pin of the Uno?

Can you please post a picture of your project so we can see your component layout?

Thanks.. Tom..