ความเร็วและทิศทางด้วยสะพานรูปตัว H

A plain transistor runs a motor in one direction. To make wheels go forward and back, you need a smarter circuit called an H-bridge. 🔁

An H-bridge uses four switches arranged like the letter H. The motor sits in the middle, and flipping pairs of switches reverses the current through it.

The L298N is a popular H-bridge module. It can drive two DC motors and handles enough current for hobby robots and small carts.

Each motor on the L298N has two direction inputs, called IN1 and IN2. Their combination decides which way the motor turns or whether it stops.

Set IN1 HIGH and IN2 LOW to spin one way; swap them to spin the other. The motor simply follows whichever input is higher. ➡️

Flip the two inputs and the current through the motor reverses. This is the magic the H-bridge gives you that a lone transistor cannot.

Set both direction inputs the same, like LOW and LOW, and the motor coasts to a halt because no net current flows through it.

Each motor also has an enable pin. Feed it a PWM signal and the duty cycle sets how fast the motor spins, just like dimming an LED.

Send PWM to the enable pin with analogWrite. A value of 255 is full speed and lower numbers slow the motor down smoothly.

The L298N takes its own motor voltage on a separate terminal. Always tie its ground to the Arduino ground so signals stay in sync.

With direction inputs plus PWM enable pins, one H-bridge lets you steer a two-wheel robot at any speed and in any direction. 🤖

On an L298N, what does the enable pin control?

An H-bridge like the L298N reverses current to change direction, while a PWM enable pin sets the speed. Share ground and you control motors fully. 🚀