Our first task is to wire up the system. This will involve hooking up the Ethernet shield to the Arduino and then building a circuit to connect the force-based resistor to the Arduino's pins. To start with, we will briefly review what resistors are.
A resistor is an electronic component with two connection points (known as terminals) that can be used to reduce the amount of electrical energy passing through a point in a circuit. This reduction in energy is known as resistance.
Note
Resistance is measured in Ohms (Ω).
You can read more about how this is calculated at http://en.wikipedia.org/wiki/Ohm's_law.
You will find that resistors are usually classified into two groups,