Understanding power requirements

The basic necessity for any electro-mechanical device is a power source. Selecting the right power source for a particular device is an important trick of trade that every Arduino tinkerer needs to know. This is exactly what will be taught in this section.

Limitations of Arduino MEGA 2560

If you look at the specifications of Arduino MEGA 2560 on the Arduino website, you will see the following:

The important thing to note is the operating voltage that says 5V. This means that no matter how large of an input voltage you put in, the MEGA will always convert it to 5V. In reality, it will be slightly less than 5V due to miscellaneous resistances. Another thing to note is the DC current per I/O pin that says 40 mA. An average micro servo has a voltage rating of 4.8 - 6V, and under heavy load, its current consumption can reach up to 1A that is 1000mA. So, it is surprising that MEGA could even power one servo sufficiently.

Choosing the right power source

Since we are...