/**
 * RFIDTest
 * 
 * Takes the serial data sent to it from the RFID on the RXD pin and output it
 * over the TXD pin.
 */

#include <stdlib.h>
#include <avr/io.h>

void RFID_Initialize()
{
	// Disable Interrupts for the UART initialization.

	/**
	 * Refer to data sheet for correct calculation for the baud clock.
	 * This must be changed everytime the main oscillator is changed.
	 */
	UBRRH = 0;
	UBRRL = 12; // 103
	
	// Set the frame format: 8 data, no parity, 1 stop, no flow control.
	UCSRC |= (1<<URSEL)|(3<<UCSZ0);

	// Enable double data rate to get a smaller margin of error in baud rate.
	UCSRA = (1<<U2X);

	// Enable the transmitter.
	UCSRB = (1<<TXEN)|(1<<RXEN);

	// Enable Interrupts.
}

void echo (uint8_t* msg)
{
	uint8_t i = 0;
	while (msg[i] != 0) {
		while (! (UCSRA & (1<<UDRE)));
		UDR = msg[i++];
	}
	return;
}

void showHourGlass()
{
	uint8_t frames[] = "-\b\\\b|\b/\b";
	echo (frames);
}

/**
 * Main
 */
int main() 
{	
	/**
	 * RFID Variables
	 */
	const uint8_t rfidTagSize = 10; // The RFID tag is twelve bytes long, but only the first ten matter. e.g. 041580983C36
	uint8_t rfidTagBuffer[rfidTagSize];
	uint8_t rfidTag[rfidTagSize];
	
	// Initialize
	RFID_Initialize();

	/**
	 * Send a statup message.
	 */
	uint8_t startupMsg[] = "Watching for RFID tags.........\r\n";
	echo (startupMsg);

	while (1) {
		
		/**
		 * Wait for RFID via serial, and store it. Then wait for the rest of the RFID.
		 * RXC 
		 */
		if ((UCSRA & (1<<RXC))) {
			//uint8_t msg[] = "Receiving RFID tag.";
			//echo (msg);

			// Reset the character counter.
			uint8_t totalCharsReceived = 0;

			/**
			 * Continue to receive all the characters.
			 */
			while (totalCharsReceived < rfidTagSize) {
				if ((UCSRA & (1<<RXC))) {

					// Wait for data to be received.
					while (!(UCSRA & (1<<RXC)));

					// Store the received byte.
					rfidTagBuffer[totalCharsReceived] = UDR;
					totalCharsReceived++;
					echo (totalCharsReceived);
				}
			}
			
			// Print the RFID tag.
			echo (rfidTagBuffer);
			uint8_t endMsg[] = "Received the tag.";
			echo (endMsg);
		}
	}
	return 0;
}