beneater / error-detection-videos

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	#include <LiquidCrystal.h>

	// Transmit rate in bps
	#define TX_RATE 5

	// Pin assignments
	#define TX_CLOCK 2
	#define TX_DATA 3
	#define LCD_D4 4
	#define LCD_D5 5
	#define LCD_D6 6
	#define LCD_D7 7
	#define LCD_RS 8
	#define LCD_EN 9
	#define CRC_OUTPUT 10
	#define CRC_READ 11
	#define CRC_CLOCK 13

	const char *message = "Hello, world!";

	void setup() {
	pinMode(TX_CLOCK, OUTPUT);
	pinMode(TX_DATA, OUTPUT);
	pinMode(CRC_OUTPUT, INPUT);
	pinMode(CRC_READ, OUTPUT);
	pinMode(CRC_CLOCK, OUTPUT);

	digitalWrite(CRC_READ, HIGH);

	// Initialize the LCD screen
	LiquidCrystal lcd(LCD_RS, LCD_EN, LCD_D4, LCD_D5, LCD_D6, LCD_D7);
	lcd.begin(16, 2);
	lcd.setCursor(0, 0);
	lcd.print(message);

	// Transmit data
	for (int byte_idx = 0; byte_idx < strlen(message); byte_idx++) {
	char tx_byte = message[byte_idx];

	// Clear the second line of the display
	lcd.noCursor();
	lcd.setCursor(0, 1);
	lcd.print(" ");
	lcd.setCursor(byte_idx, 0);
	lcd.cursor();

	for (int bit_idx = 0; bit_idx < 8; bit_idx++) {
	bool tx_bit = tx_byte & (0x80 >> bit_idx);

	digitalWrite(TX_DATA, tx_bit);
	delay((1000 / TX_RATE) / 2);

	// Update the LCD
	lcd.noCursor();
	lcd.setCursor(bit_idx, 1);
	lcd.print(tx_bit ? "1" : "0");
	lcd.setCursor(byte_idx, 0);
	lcd.cursor();

	// Pulse clock
	digitalWrite(TX_CLOCK, HIGH);
	digitalWrite(CRC_CLOCK, HIGH);
	delay((1000 / TX_RATE) / 2);
	digitalWrite(TX_CLOCK, LOW);
	digitalWrite(CRC_CLOCK, LOW);
	}
	}

	// Fill the CRC circuit with 16 zeros
	digitalWrite(TX_DATA, LOW);
	for (int i = 0; i < 16; i += 1) {
	delay((1000 / TX_RATE) / 2);
	digitalWrite(CRC_CLOCK, HIGH);
	delay((1000 / TX_RATE) / 2);
	digitalWrite(CRC_CLOCK, LOW);
	}

	// Read CRC from CRC circuit and transmit it
	digitalWrite(CRC_READ, LOW);
	lcd.setCursor(0, 1);
	lcd.print(" ");
	lcd.setCursor(0, 1);
	for (int i = 0; i < 16; i += 1) {
	lcd.print(digitalRead(CRC_OUTPUT) ? "1" : "0");
	digitalWrite(TX_DATA, digitalRead(CRC_OUTPUT));

	delay((1000 / TX_RATE) / 2);
	digitalWrite(CRC_CLOCK, HIGH);
	digitalWrite(TX_CLOCK, HIGH);
	delay((1000 / TX_RATE) / 2);
	digitalWrite(CRC_CLOCK, LOW);
	digitalWrite(TX_CLOCK, LOW);
	}

	digitalWrite(TX_DATA, LOW);
	}

	void loop() {
	// put your main code here, to run repeatedly:

	}