I am a beginner in Arduino.
I want to connect 2 motors to Arduino. Why do we require txhe motor shield? And if yes please explain why is it required? Also can I use an amplifier for the same.
Another question, I have SLAEX039 L293D Motor Shield. Does using this motor shield restrict arduino's pin usage? I mean we can't use the arduino pins if we use the motor shield right, can we?
Thank a lot
The core reason that we require motor shields is because the Arduino, on its own, cannot power a motor with its IO pins.
The digital IO pins on the AVR based Arduinos (such as the Uno) are only rated to supply up to 40mA of current at 5V - they are designed for signalling hardware, not driving loads such as motors, that can run to several Amps at higher voltages at peak loads.
Fortunately, there are devices that are designed to control heavy loads such as motors based on these logic level signals - we typically call these drivers. The L293D is such a driver, which connects to a logic device like the Arduino for signalling and then drives a motor from another supply.
While you can use a cheap, standalone L293D device on its own, it's often more convenient to use one carried on a shield, which correctly connects the driver as well as provides connectors for the external power and motor.
Ultimately, you don't require a shield, but you do need some form of driver to take the logic level signals from the Arduino, and shields are convenient ways of providing these.
http://www.ti.com/lit/ds/symlink/l293.pdf is a datasheet for a L293D device from TI, showing the various ways it can drive a motor based on the signals it receives.
