======STL1======
=====REVIEW OF BITWISE LOGIC=====
Relational Operators:
- "==" is equal to
- "!=" is not equal to
- "<" is less than
- ">" is greater than
- "<=" less than or equal to
- ">=" greater than or equal to
====BITWISE AND====
The output of bitwise AND is **1** if the corresponding bits of the two operands is **1**. If either bit of an operand is **0**, the result is **0**. In C, the bitwise AND operator is denoted by "&".
====USING BINARY====
To show that a number is in binary, use 0b before it. For example: 0b0000 would represent 0 in binary and 0b1111 would be equivalent to 15 in the decimal system. Otherwise, 1111 may be confused for 1,111 in decimal. This project can be done in decimal, but it may make it easier to use decimal, because 0b0010 definitely requires the twos place LED to light up, since the LEDs are counting in binary.
====LIGHT PATTERN====
(0000) = (4th, 3rd, 2nd, 1st)
0 0 0 0 (0) - ZERO LIGHTS ON
0 0 0 1 (1) - 1ST LIGHT ON
0 0 1 0 (2) - 2nd LIGHT ON
0 0 1 1 (3) - 1st AND 2nd LIGHTS ON
0 1 0 0 (4) - 3rd LIGHT ON
0 1 0 1 (5) - 3rd AND 1st LIGHTS ON
0 1 1 0 (6) - 3rd and 2nd LIGHTS ON
0 1 1 1 (7) - 3rd, 2nd and 1st LIGHTS ON
1 0 0 0 (8) - 4th LIGHT ON
1 0 0 1 (9) - 4th and 1st LIGHTS ON
1 0 1 0 (10)- 4th and 2nd LIGHTS ON
1 0 1 1 (11)- 4th, 2nd and 1st LIGHTS ON
1 1 0 0 (12)- 4th and 3rd LIGHTS ON
1 1 0 1 (13)- 4th,3rd and 1st LIGHTS ON
1 1 1 0 (14)- 4th,3rd and 2nd LIGHTS ON
1 1 1 1 (15)- 4th,3rd,2nd and 1st LIGHTS ON
0 0 0 0
0 0 0 1
0 0 1 0
====BITWISE INCLUSIVE OR====
The bitwise inclusive OR, is represented in C with a vertical bar symbol (often referred to as a pipe): |
This operator compares the values of some operands in binary and yields a string of bits that contains all the bits of each operand (OR operation).
Example:
**01100011 | 00011001**
yields **01111011**
Similarly, you can perform this operation in any base, including decimal:
**10 | 4**
is equal to **7** because 00001010 | 00000100 == 00001110
====BITWISE EXCLUSIVE OR====
Exclusive OR, typically referred to as XOR, is denoted by the ^ operator in C.
XOR compares some operands in binary, and for each bit compared yields 1 if and only if the bits of each operand have one and only one 1 between them.
Example:
1011 ^ 1101 == 0110
This of course can be done with integers of any base, like so:
3 ^ 7 == 4
Which would be interpreted in binary as:
0011 ^ 0111 == 0100
XOR is an important operation that, when combined with AND, can do operations such as binary addition.
====BITWISE NOT====
The bitwise NOT operation, represented with the operator ~, can be thought of simply as an inverter. That is, it takes some operand and inverts each bit.
Example:
~0011 == 1100
This can be done for different bases as well:
~5 == 10
Because **5** is represented in binary as **0101**, inverting the bits results in binary **1010**, i.e. decimal **10**.
=====SELECTION STRUCTURES: IF=====
For this project, we will mainly be using the **if** and **else** functions. An **IF** statement tells the computer that when the condition specified by the statement is met, then to do the command string later specified. When the condition specified by the statement is not met, it will completely skip the function and continue on its journey to make you frustrated. BUT, we can add an **else** command to tell the computer to do a task or command string when the condition isn't met.
For example, here is the outline of the **IF** statement we should be using: