I've got an L298N dual H-bridge which I'm using to control two DC motors with an arduino. I want to be able to control the speed of the two motors using PWM. My understanding is that I need to connect the two enabling pins ENA and ENB to PWM pins on the arduino (please correct me if I'm wrong).

If you notice closely at the picture of the dual H-bridge, you'll notice that the ENA and ENB pins are enclosed by jumpers connecting each of them to a 5V pin. I believe that I need to remove the jumper in order to utilize the enabling pins directly (again, please correct me if I'm wrong).

If all the above is true, then this leads me to my primary question: How do I remove these jumpers?

I've tried to remove them just by pulling on them with my bare fingers, but they don't seem to come out at all. My fingertips are very large in comparison to the jumpers themselves and can't grasp them very easily. I'm not sure if using pliers will damage the board in any way.

I'm a newbie at this, and I'm not sure how strongly attached the jumpers are to the board. Is there any special trick to removing them?

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    \$\begingroup\$ You can use a small plier in order to grab the jumper cap securely and pull it. \$\endgroup\$ – alexan_e Jan 3 '14 at 8:42

I've looked at the picture and these jumpers seems to be usual ones. So they just probably a bit stuck there. Feel free to apply up to 1kg of force with the help of pliers.

Regarding usage of ENA/ENB for speed control using PWM - you are correct.

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  • \$\begingroup\$ Question: But if I dont need speed control, can I just leave the jumper on and not connect the ENA pin to the arduino? Or do I always have to connect the ENA pin to the Arduino? \$\endgroup\$ – marciokoko Sep 10 '18 at 18:15
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    \$\begingroup\$ @marciokoko Depending on whether it has pull-up/down resistors implemented on the module/chip to always enable it. Most likely you can leave it not connected. \$\endgroup\$ – BarsMonster Sep 11 '18 at 2:50

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