/* rf.c*/
#include "../shared.h"
#include "door.h"
#include "rf.h"


/* buffers */
static unsigned char in_buffer [IN_BUFFER_SIZE];
static unsigned char out_buffer [OUT_BUFFER_SIZE];

/* total # of bytes received into in_buffer */
static unsigned char bytes_received = 0;
/* # of bytes sent from out_buffer */
static unsigned char bytes_sent = 0;
/* total # of bytes to send from out_buffer */
static unsigned char bytes_to_send = 0;


/* # of 10ms before timeout */
static unsigned char overflow_count = 0;
/* time out flag */
static bit timed_out = 0;
char value = 0x01;

char xdata *ledaddress = 0x0f000;  // the FPGA is configured to memory map led to this address

static void switch_to(unsigned char nextState) {
	TR0 = 0;
	TR1 = 0;
	bytes_to_send = 0;
	state = nextState;
}


void RF_Task() {
	P1 = 0x00;
	*ledaddress = 0x5B; //3
	RF_init();

	//generate request packet
	format_request(out_buffer);
	
	//send address byte of packet to test if RF board is busy
	bytes_received = 0;
	bytes_sent = 0;
	bytes_to_send = 1;
	set_timeout(5);
	TI = 1;

	//wait till RF board is NOT busy
	while(1) {
//		*ledaddress = 0x52;//7
		if (bytes_received > 0) {
			if(in_buffer[0] == out_buffer[0]) {
				unset_timeout();
		    	//address byte echoed; send the rest of packet
				bytes_to_send = HEADER_LENGTH + REQUEST_LENGTH;
				//assert(bytes_sent == 1);
				TI = 1;
				break;
			}
			bytes_received = 0;
		} else if (timed_out) {
			//test again
			bytes_sent = 0;
			set_timeout(5);
			TI = 1;
		}				
	}


	//wait till whole packet has been sent
	while(bytes_sent < bytes_to_send) ;

	*ledaddress = 0x3A; //4

	bytes_received = 0;
	//wait for reply packet (includes BadgeID)
	set_timeout(50);//0.5 sec time-out
	while(1) { 
		if(bytes_received >= HEADER_LENGTH + RESPONSE_LENGTH) {
			unset_timeout();
			//pass badgeID to FPGA for checking
			badgeID = in_buffer[HEADER_LENGTH + RESPONSE_LENGTH -1 -1];
			P1 = badgeID;
			switch_to(CHECKING_ID);
		
			*ledaddress = 0x6B; //5
//			*ledaddress = badgeID;		// to be deleted later
			return;
		} else if(timed_out) {
			unset_timeout();
//			switch_to(DETECTING_USER);
			*ledaddress = 0x6F; //6
			return;
		}
	}
}/* end RF_Task */


static void set_timeout(unsigned char n) {
	overflow_count = n;
	timed_out = 0;
	TH0 = RF_RELOAD_HI;
	TL0 = RF_RELOAD_LO;
	TR0 = 1;
}


static void unset_timeout() {
	TR0 = 0;
	TF0 = 0;
	timed_out = 0;	
}


void RF_Timer0_handler() {
	if(--overflow_count==0) {
		timed_out = 1;
		TR0 = 0;		
	}
	TH0 = RF_RELOAD_HI;
	TL0 = RF_RELOAD_LO;
} //end of RF_Timer0_handler()


void RF_Serial_handler() {
	if(RI==1) {
		RI = 0;
		if(bytes_received < IN_BUFFER_SIZE)
			in_buffer[bytes_received++] = SBUF;
	} else {	
		TI = 0;
		if(bytes_sent < bytes_to_send)
			SBUF = out_buffer[bytes_sent++];
	}
} /* end of RF_Serial_handler() */


/* create the request packet in out_buffer */
static void format_request(char* out_buffer) {
	out_buffer[0] = BADGE_ADDRESS;
	out_buffer[0] <<= 4;
	out_buffer[0] |= 4;

	out_buffer[1] = 8; //telemetry mode
	out_buffer[2] = REQUEST_LENGTH;
	//out_buffer[3] = REQUEST_CODE;
	out_buffer[3] = 2;
	//out_buffer[4] = REQUEST_CODE;
	out_buffer[4] = badgeID;
	out_buffer[5] = 3;
} //end of format_reply


static void RF_init() {

	/* interrupt settings */
	EA = 1;
	ET0 = 1;
	ET1 = 0;
	ES = 1;

	/* set serial */
	SM0 = 0;
	SM1 = 1;
	REN = 1;

	/* setup timer0 as a 10 ms counter, timer1 as 19.2 kbps baud rate generator, assuming a 25MHz clock */
	TMOD = 0x21;
	PCON = PCON | 0x80;
	TH0 = RF_RELOAD_HI;
	TL0 = RF_RELOAD_LO;
	TH1 = 249;
	TR1 = 1;


}/* end of RF_init() */