Resistor Color
Resistor Color

Resistor Color



If you want to build something using a Raspberry Pi, you'll probably use resistors. For this exercise, you need to know two things about them:

  • Each resistor has a resistance value.
  • Resistors are small - so small in fact that if you printed the resistance value on them, it would be hard to read.

To get around this problem, manufacturers print color-coded bands onto the resistors to denote their resistance values. Each band has a position and a numeric value.

The first 2 bands of a resistor have a simple encoding scheme: each color maps to a single number.

In this exercise you are going to create a helpful program so that you don't have to remember the values of the bands.

These colors are encoded as follows:

  • black: 0
  • brown: 1
  • red: 2
  • orange: 3
  • yellow: 4
  • green: 5
  • blue: 6
  • violet: 7
  • grey: 8
  • white: 9

The goal of this exercise is to create a way:

  • to look up the numerical value associated with a particular color band
  • to list the different band colors

Mnemonics map the colors to the numbers, that, when stored as an array, happen to map to their index in the array: Better Be Right Or Your Great Big Values Go Wrong.

More information on the color encoding of resistors can be found in the Electronic color code Wikipedia article.

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