INSTRUCTIONS FOR SERIAL PORT PROTOCOL
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This project implements a protocol for file transfer using a serial port cable. The protocol enables reliable communication between a transmitter and a receiver, even in the presence of cable disconnections or noise.

Project Structure
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- bin/: Compiled binaries.
- src/: Source code for the implementation of the link-layer and application layer protocols. Students should edit these files to implement the project.
- include/: Header files of the link-layer and application layer protocols. These files must not be changed.
- cable/: Virtual cable program to help test the serial port. This file must not be changed.
- main.c: Main file. This file must not be changed.
- Makefile: Makefile to build the project and run the application.
- penguin.gif: Example file to be sent through the serial port.

Instructions to Run the Project
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1. Edit the source code in the src/ directory.
2. Compile the application and the virtual cable program using the provided Makefile.
3. Run the virtual cable program (either by running the executable manually or using the Makefile target):
	$ sudo ./bin/cable_app
	$ sudo make run_cable

4. Test the protocol without cable disconnections and noise
	4.1 Run the receiver (either by running the executable manually or using the Makefile target):
		$ ./bin/main /dev/ttyS11 9600 rx penguin-received.gif
		$ make run_tx

	4.2 Run the transmitter (either by running the executable manually or using the Makefile target):
		$ ./bin/main /dev/ttyS10 9600 tx penguin.gif
		$ make run_rx

	4.3 Check if the file received matches the file sent, using the diff Linux command or using the Makefile target:
		$ diff -s penguin.gif penguin-received.gif
		$ make check_files

5. Test the protocol with cable disconnections and noise
	5.1. Run receiver and transmitter again
	5.2. Quickly move to the cable program console and press 0 for unplugging the cable, 2 to add noise, and 1 to normal
	5.3. Check if the file received matches the file sent, even with cable disconnections or with noise