The L298N motor driver IC can control two motors at a time. It consists of a dual H-bridge circuit. This means it consists of two circuits that look like the one shown in the following diagram, one for each motor:
The H-bridge circuit consists of four switches S1, S2, 
, and 
. These switches will open and close based on the input that we provide to the L298N IC.
Now, since we have two motors, there are four possible input combinations that we can provide to the L298N IC, as follows:
- HIGH HIGH (1, 1)
- HIGH LOW (1, 0)
- LOW HIGH (0, 1)
- LOW LOW (0, 0)
We will provide the HIGH (1) and LOW (0) signal to the S1 and S2 switches, as follows:
- First, when S1 = 1 and S2 =0, the S1 switch will be closed and the S2 switch will remain open.
, or 
, will be 0, so the 
switch will be open. 
, or 
, will be 1, so the 
switch will be closed. Now, since the S1 and 
switches are closed, the current will flow from the Vcc to the S1, then to the motor, then to the 
, and end at the GND. The motor will rotate in a clockwise direction, as shown in the following diagram:
- When S1 = 0 and S2 = 1, the S1 switch will be open, the S2 switch will be closed, the
will be closed, and the 
will be open. Now, since the S2 and 
switches are closed, the current will flow from the Vcc to the S2, then to the motor, then to the 
, and end at the GND. The motor will rotate in an anticlockwise direction, as shown in the following diagram:
- When S1 = 0 and S2 = 0, the S1 switch will be open, the S2 switch will be open, the
switch will be closed, and the 
switch will be closed. Now, since both the S1 and S2 switches are open, there is no path for the current to flow toward the motors. In this case, the motor will stop, as shown in the following diagram:
- When S1 = 1 and S2 = 1, the S1 and S2 switches will be closed, while the
and 
switches will be open. Since both the S1 and S2 switches are closed, this will create a short circuit condition and the current will not move through the motor. In this case, the motor will stop, as in the previous case:
As explained earlier, since the L298N IC consists of two H-bridges, the same process will take place in the other H-bridge when we provide high and low signals. The second H-bridge will control the other motor.