/*---------------------------------------------*\
|  RGB Fan Controller - Serial Port Code File	|
|  This file contains the functionality of the	|
|  buffered serial port.  It uses a buffer array|
|  and a position value.  The default buffer	|
|  size is 64 bytes, though you can increase 	|
|  it if you need a larger buffer.				|
|												|
|  Adam Honse (CalcProgrammer1), 2010			|
\*---------------------------------------------*/
#include "fanbus.h"

unsigned char fanbus_serial_buffer[5]; //Serial buffer
extern char outlet;
extern char state;
//USART Receive interrupt pushes the incoming byte into the buffer
ISR(USART_RX_vect)
{
	//Shift in new data
	fanbus_serial_buffer[0] = fanbus_serial_buffer[1];
	fanbus_serial_buffer[1] = fanbus_serial_buffer[2];
	fanbus_serial_buffer[2] = fanbus_serial_buffer[3];
	fanbus_serial_buffer[3] = fanbus_serial_buffer[4];
	fanbus_serial_buffer[4] = UDR;

	//Test if valid write packet
	if(fanbus_serial_buffer[0] == 0x00 && fanbus_serial_buffer[4] == 0xFF && fanbus_serial_buffer[2] == 0xAA)
	{
		fanbus_transmit('A');
		state = fanbus_serial_buffer[3];
		outlet = fanbus_serial_buffer[1];
	}
}

void fanbus_init(unsigned int baud)
{
	//Set baud rate
	UBRRH = (unsigned char) (baud >> 8);
	UBRRL = (unsigned char) (baud);

	//Set frame format: 8 data, no parity, 2 stop bits
	UCSRC = (0<<UMSEL) | (0<<UPM0) | (0<<USBS) | (3<<UCSZ0);

	//Enable receiver and transmitter
	UCSRB = (1<<RXCIE | 1<<RXEN) | (1<<TXEN);

	sei();
}

void fanbus_transmit(unsigned char data)
{
	//Wait for empty transmit buffer
	while(!(UCSRA & (1<<UDRE)));

	//Put data into buffer, send data
	UDR = data;
}