A motor driver lets a microcontroller control a DC motor without sending motor current through its GPIO pins. Two modules often encountered in hobby robotics are the L298N and TB6612FNG. Both can control two brushed DC motors, but their electrical behaviour and practical limits are different.
What matters more than the module name?
Before choosing a driver, find the motor’s rated voltage and stall current. Stall current is the current the motor may draw when the shaft is blocked or starting under a heavy load. A driver that looks adequate at no load can overheat or trigger a battery voltage drop during a turn or a stalled wheel.
| Factor | L298N module | TB6612FNG module |
|---|---|---|
| Driver technology | Bipolar transistor H-bridge | MOSFET H-bridge |
| Voltage loss | Relatively high; driver can get warm | Generally lower voltage loss |
| Typical use | Common educational kits and larger modules | Compact battery-powered robots with suitable motors |
| Current capability | Depends heavily on module cooling and conditions | Depends on board layout, cooling and operating conditions |
| Logic supply | Follow the specific module design | Separate logic supply is typically provided |
Do not select either driver from a headline current figure alone. Read the chip datasheet and module documentation, and allow margin for startup and stall current.
Why a motor may feel weak with an L298N
The L298N has a noticeable voltage drop across its output stage. If a battery pack provides a limited voltage, the motor receives less than the battery voltage, especially under load. The driver also dissipates power as heat. This can make a small robot slower than expected even when the battery appears charged.
If one motor is much weaker than the other, do not immediately blame software. Measure battery voltage with the robot stopped and while the motors are running. Then compare the driver outputs, inspect screw terminals and connectors, check for a binding wheel, and test the motors individually only when it is safe to do so. A reading near zero at one output pair may indicate a wiring, enable-pin, driver or power problem; it is not proof of a single cause.
Wiring checklist
- Connect each motor to the correct output pair.
- Connect the driver’s logic inputs to the microcontroller as shown in the module documentation.
- Connect microcontroller ground and driver ground together.
- Use a battery and regulator appropriate for both motor and logic voltage.
- Use the enable/PWM pins for speed control only after confirming the module’s jumper arrangement.
- Disconnect the battery before moving wires or changing motor connections.
Never connect a motor directly to an Arduino or ESP32 GPIO. Motor noise can reset the controller, so keep power wiring short, secure the connections, and use suitable decoupling. Do not power a high-current motor from the controller’s 5 V output.
Which one should you choose?
The L298N can be reasonable for a first experiment if you already have the module and your motors draw modest current. If you are designing a compact battery-powered rover from scratch, a modern MOSFET driver such as a correctly rated TB6612FNG board can waste less power. The right choice still depends on the motor’s stall current, supply voltage and the actual module’s thermal design.
Test before competition day
- Lift the chassis so wheels can spin freely.
- Run each motor at a low PWM value and confirm the direction.
- Check that both motors start reliably from rest.
- Repeat on the floor, where the motors experience real load.
- Measure battery voltage under load and check for excessive driver heating.
For the complete project parts list, see the Arduino and ESP32 checklist. Browse Pandey Electronics for motor drivers, boards and robotics components, and confirm current ratings against the motor datasheet before buying.
Bottom line: a motor driver is a power component, not just a pin adapter. Match it to stall current, supply voltage and cooling needs, then verify the full system under load.