PROJECT: Seeing The Light (STL1)

OBJECTIVE

We continue our explorations of the electronics kit, by adding additional LEDs to control them in unison with a C program on our pi, having them count in binary.

PROCESS

Do note, the productive way to go about this project involves taking the following steps:

starting early
reading the project page
asking questions regarding things you do not know, are not clear on, or are confused about
as information, concepts, processes become clear, that is something you can contribute to the project documentation (so you can better remember)

If you start too late, and do not ask questions, and do not have enough time and don't know what is going on, you are not doing the project correctly.

TASK

After exploring, assembling, and testing the intended circuit (4 LEDs), adapt the provided C code to use the bank of connected LEDs to count in binary from 0000 to 1111 (0 to 15).

Using the current value of count, your task is to make use of if statements and bitwise logic to determine from an ongoing count the state of the individual bits.

It is your task to write a C program that interfaces successfully with four independently connected LED circuits, arranged in some orientation to ascertain an order or positioning, where your program will (in endless fashion, or until being manually interrupted) display a count (in binary) of values from 0 to 15 (then rollover, or reset).

If “1” means the LED in that position is ON, and “0” means the LED in that position is OFF, then you want to write a program that performs the following progression (over and over again):

0 0 0 0
0 0 0 1
0 0 1 0
0 0 1 1
0 1 0 0
0 1 0 1
0 1 1 0
0 1 1 1
1 0 0 0
1 0 0 1
1 0 1 0
1 0 1 1
1 1 0 0
1 1 0 1
1 1 1 0
1 1 1 1   <-- 15, the maximum value to display
0 0 0 0   <-- 0, we "roll over" and start again
0 0 0 1
0 0 1 0
...

GRABIT

To assist with consistency across all implementations, data files for use with this project are available on lab46 via the grabit tool. Be sure to obtain it and ensure your implementation properly works with the provided data.

lab46:~/src/SEMESTER/DESIG$ grabit DESIG PROJECT

EDIT

You will want to go here to edit and fill in the various sections of the document:

https://lab46.g7n.org/notes/c4eng/fall2023/projects/stl1

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:

  if (statement) {
       do this;
   }
       else {
           do this instead;
    }

Where statement is the statement you want to test as true or false, and both do this and do this instead are other functions, commands, or whatnot. When the statement is true, it will run the do this line. But when the statement is false, it will run the do this instead line.

STRATEGY

The general flow of the process (one way of going about it, anyway) can be described as follows:

SET COUNTER TO ZERO
REPEAT:
    SHOULD THE ONE'S POSITION HAVE A ONE:
        ACTIVATE THE ONE'S PLACE
    OTHERWISE:
        DEACTIVATE THE ONE'S PLACE

    SHOULD THE TWO'S POSITION HAVE A ONE:
        ACTIVATE THE TWO'S PLACE
    OTHERWISE:
        DEACTIVATE THE TWO'S PLACE

    SHOULD THE FOUR'S POSITION HAVE A ONE:
        ACTIVATE THE FOUR'S PLACE
    OTHERWISE:
        DEACTIVATE THE FOUR'S PLACE

    SHOULD THE EIGHT'S POSITION HAVE A ONE:
        ACTIVATE THE EIGHT'S PLACE
    OTHERWISE:
        DEACTIVATE THE EIGHT'S PLACE

    PAUSE FOR HUMAN PERCEPTION

    LET THE COUNTER BE INCREMENTED BY ONE

SUBMISSION

To be successful in this project, the following criteria (or their equivalent) must be met:

Project must be submit on time, by the deadline.
- Late submissions will lose 33% credit per day, with the submission window closing on the 3rd day following the deadline.
All code must compile cleanly (no warnings or errors)
- Compile with the -Wall and –std=gnu18 compiler flags
- all requested functionality must conform to stated requirements (either on this document or in a comment banner in source code files themselves).
Executed programs must display in a manner similar to provided output
- output formatted, where applicable, must match that of project requirements
Processing must be correct based on input given and output requested
Output, if applicable, must be correct based on values input
Code must be nicely and consistently indented
Code must be consistently written, to strive for readability from having a consistent style throughout
Code must be commented
- Any “to be implemented” comments MUST be removed
  - these “to be implemented” comments, if still present at evaluation time, will result in points being deducted.
  - Sufficient comments explaining the point of provided logic MUST be present
No global variables (without instructor approval), no goto statements, no calling of main()!
Track/version the source code in your lab46 semester repository
Submit a copy of your source code to me using the submit tool (make submit on lab46 will do this) by the deadline.

Submit Tool Usage

Let's say you have completed work on the project, and are ready to submit, you would do the following (assuming you have a program called uom0.c):

lab46:~/src/SEMESTER/DESIG/PROJECT$ make submit

You should get some sort of confirmation indicating successful submission if all went according to plan. If not, check for typos and or locational mismatches.

RUBRIC

I'll be evaluating the project based on the following criteria:

39:stl1:final tally of results (39/39)
*:stl1:used grabit to obtain project by the Sunday prior to duedate [6/6]
*:stl1:clean compile, no compiler messages [7/7]
*:stl1:program conforms to project specifications [20/20]
*:stl1:code tracked in lab46 semester repo [6/6]

Pertaining to the collaborative authoring of project documentation

each class member is to participate in the contribution of relevant information and formatting of the documentation
- minimal member contributions consist of:
  - near the class average edits (a value of at least four productive edits)
  - near the average class content change average (a value of at least 256 bytes (absolute value of data content change))
  - near the class content contribution average (a value of at least 1kiB)
  - no adding in one commit then later removing in its entirety for the sake of satisfying edit requirements
- adding and formatting data in an organized fashion, aiming to create an informative and readable document that anyone in the class can reference
- content contributions will be factored into a documentation coefficient, a value multiplied against your actual project submission to influence the end result:
  - no contributions, co-efficient is 0.50
  - less than minimum contributions is 0.75
  - met minimum contribution threshold is 1.00

Additionally

Solutions not abiding by spirit of project will be subject to a 50% overall deduction
Solutions not utilizing descriptive why and how comments will be subject to a 25% overall deduction
Solutions not utilizing indentation to promote scope and clarity or otherwise maintaining consistency in code style and presentation will be subject to a 25% overall deduction
Solutions not organized and easy to read (assume a terminal at least 90 characters wide, 40 characters tall) are subject to a 25% overall deduction

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Table of Contents

PROJECT: Seeing The Light (STL1)

OBJECTIVE

PROCESS

TASK

GRABIT

EDIT

STL1

REVIEW OF BITWISE LOGIC

BITWISE AND

USING BINARY

LIGHT PATTERN

BITWISE INCLUSIVE OR

BITWISE EXCLUSIVE OR

BITWISE NOT

SELECTION STRUCTURES: IF

STRATEGY

SUBMISSION

Submit Tool Usage

RUBRIC

Pertaining to the collaborative authoring of project documentation

Additionally

Lab46 Wiki

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Table of Contents

PROJECT: Seeing The Light (STL1)

OBJECTIVE

PROCESS

TASK

GRABIT

EDIT

STL1

REVIEW OF BITWISE LOGIC

BITWISE AND

USING BINARY

LIGHT PATTERN

BITWISE INCLUSIVE OR

BITWISE EXCLUSIVE OR

BITWISE NOT

SELECTION STRUCTURES: IF

STRATEGY

SUBMISSION

Submit Tool Usage

RUBRIC

Pertaining to the collaborative authoring of project documentation

Additionally

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