Powering the robot
The robot needs power for all its parts. We must consider two major power systems: the power for all the digital parts, such as the Raspberry Pi and sensors, and then the power for the motors.
Motors need a separate power system for a few reasons. First, they consume far more electrical power than most other components on the robot. They may require different voltages; I've seen low-voltage, high-current motor supplies and high-voltage supplies too. The other reason that they need their own power system is that they can cause interference. They can pull enough power that other circuitry has brownouts. A brownout is when circuitry has a voltage drop that is low or long enough to get into an inconsistent or reset state. Resets can lead to SD card corruption on a Pi. Motors can also introduce electrical noise to a power line as they are used, which could cause digital parts to misbehave.
There are two primary strategies for powering a robot with motors:
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