Datasheet

Chapter 2 • Shield, Lights, Servo Motors
48 • Robotics with the BOE Shield-Bot
Resistor Color Code Values
Each color bar on the resistor's case corresponds to a digit, as listed in the table below.
Digit 0 1 2 3 4 5 6 7 8 9
Color black brown red orange yellow green blue violet gray white
Here’s how to find the resistor’s value, in this case proving that yellow-violet-brown is really
470 Ω:
1. The first stripe is yellow, which means the leftmost digit is a 4.
2. The second stripe is violet, which means the next digit is a 7.
3. The third stripe is brown. Since brown is 1, it means add one zero to the right of
the first two digits.
Yellow-Violet-Brown = 4-7-0 = 470 Ω.
Your Turn
 Use the table and picture above to figure out the color code for the 220 Ω
resistors you will need for the indicator lights.
Introducing the LED
A diode is a one-way electric current valve, and a light-emitting diode (LED) emits light when
current passes through it. Since an LED is a one-way current valve, you have to make sure to
connect it the right way for it to work as intended.
An LED has two terminals: the anode and the cathode. The anode lead is labeled with the
plus-sign (+) in the part drawing, and it is the wide part of the triangle in the schematic
symbol. The cathode lead is the pin labeled with a minus-sign (-), and it is the line across the
point of the triangle in the schematic symbol.
First Digit
Second Digit
Number of Zeros
Tolerance
Code