/*    mija 2008
      demo for RFM12B - RX 868MHz

	  CPU ATMEGA8
      fcpu = 1MHz

	  !! define PIN,PORT,DDR for IOpin !!
*/

#include <avr/io.h>
#include <util/delay.h>
#include "RFM12B.h"

//************************************************************************

#define SDI    		PB3
 #define SDI_PORT	PORTB
 #define SDI_DDR	DDRB

#define FSK    		PC1
 #define FSK_PORT	PORTC
 #define FSK_DDR	DDRC

#define SDO    		PB4		// input for mega
 #define SDO_PORT	PORTB
 #define SDO_DDR	DDRB
 #define SDO_PIN	PINB

#define SCK    		PB5
 #define SCK_PORT	PORTB
 #define SCK_DDR	DDRB

#define nIRQ   		PD2      // input for mega
 #define nIRQ_PORT	PORTD
 #define nIRQ_DDR	DDRD
 #define nIRQ_PIN	PIND

#define nSEL   		PB2
 #define nSEL_PORT	PORTB
 #define nSEL_DDR	DDRB

#define LED   		PD3
 #define LED_PORT	PORTD
 #define LED_DDR	DDRD

// interni
#define SDI_H		SDI_PORT |= _BV(SDI)
#define SDI_L		SDI_PORT &= (~(_BV(SDI)))
#define SDI_INIT	SDI_DDR |= _BV(SDI)

#define FSK_H		FSK_PORT |= _BV(FSK)
#define FSK_L		FSK_PORT &= (~(_BV(FSK)))
#define FSK_INIT	FSK_DDR |= _BV(FSK)

#define SDO_INPUT	(SDO_PIN & _BV(SDO))
#define SDO_INIT	SDO_DDR &= (~(_BV(SDO)))

#define SCK_H		SCK_PORT |= _BV(SCK)
#define SCK_L		SCK_PORT &= (~(_BV(SCK)))
#define SCK_INIT	SCK_DDR |= _BV(SCK)

#define nIRQ_INPUT	(nIRQ_PIN & _BV(nIRQ))
#define nIRQ_INIT	nIRQ_DDR &= (~(_BV(nIRQ)))

#define nSEL_H		nSEL_PORT |= _BV(nSEL)
#define nSEL_L		nSEL_PORT &= (~(_BV(nSEL)))
#define nSEL_INIT	nSEL_DDR |= _BV(nSEL)

#define LED_H		LED_PORT |= _BV(LED)
#define LED_L		LED_PORT &= (~(_BV(LED)))
#define LED_INIT	LED_DDR |= _BV(LED)

#define START_FIFO	RF_WRITE_CMD(CMD_FIFO|FIFO_8|FIFO_FF|FIFO_DR)
#define STOP_FIFO	RF_WRITE_CMD(CMD_FIFO)

//************************************************************************

uint8_t rx_buf[16];

//************************************************************************

void delay_ms(uint16_t time)
{
	while(time--) _delay_ms(1);
}

void IO_INIT(void)
{
	SDI_INIT;
	SDO_INIT;
	SCK_INIT;
	nIRQ_INIT;
	nSEL_INIT;
	FSK_INIT;
	LED_INIT;
}

void RF_INIT(void)
{
   nSEL_H;
   SDI_H;
   SCK_L;
   nIRQ_INPUT;
   SDO_INPUT;
   FSK_H;
}

uint16_t RF_WRITE_CMD(uint16_t cmd)
{
   uint8_t i;
   uint16_t temp;

   SCK_L;
   nSEL_L;
   temp=0;
   for (i=0;i<16;i++)
   {
      if (cmd & 0x8000) SDI_H;
      else SDI_L;
	  SCK_H;
      cmd <<= 1;
	  temp <<= 1;
	  if(SDO_INPUT) temp |= 0x0001;
	  SCK_L;
   }
   SCK_L;
   nSEL_H;
   return (temp);
}

void RF_WRITE_DATA(uint8_t data)
{
	  while (nIRQ_INPUT);
      RF_WRITE_CMD(0xB800 + data);
}

uint8_t RF_READ_DATA(void)
{
	while (nIRQ_INPUT);
	RF_WRITE_CMD(0x0000);
	return (0x00FF & RF_WRITE_CMD(0xB000));
}


void RS232_INIT(void)
{	
	//set baud rate 9600 8N1 for Fosc 1MHz
	UBRRH = 0;
	UBRRL = 12;
	UCSRB = (1<<RXEN)|(1<<TXEN);	//enable RX TX	
	UCSRC = (1<<URSEL) |(3<<UCSZ0);	//8N1
	UCSRA  |= _BV(U2X);
}

void put_rs232(char data)
{
	// Wait for empty transmit buffer
	while ( !( UCSRA & (1<<UDRE)) );
	// Put data into buffer, sends the data
	UDR = data;
}



int main()
{
   	uint8_t i,j,ChkSum;
   	uint8_t LED_TRG;
   	uint8_t b;

   	IO_INIT();
   	RF_INIT();
   	RS232_INIT();
   	LED_H;
   	delay_ms(1000);
   	LED_L;
   	LED_TRG=0;

	RF_WRITE_CMD(CMD_SETTING 	|SETTING_EL	|SETTING_EF	|BAND_868	|C_12pF				);
   	RF_WRITE_CMD(CMD_POWER		|POWER_ER	|POWER_EBB	|POWER_ES	|POWER_EX	|POWER_DC);
   	RF_WRITE_CMD(CMD_FREQUENCY	|FREQUENCY_868											);
   	RF_WRITE_CMD(CMD_RATE		|RATE_9600												);
   	RF_WRITE_CMD(CMD_RX			|RX_P16		|VDI_FAST	|BANDWIDTH_67|LNA_GAIN_0|DRSSI_103);
   	RF_WRITE_CMD(CMD_FILTER		|FILTER_AL	|DQD_4										);
	RF_WRITE_CMD(CMD_FIFO		|FIFO_8		|FIFO_DR									);
	RF_WRITE_CMD(CMD_SYNCFIFO	|0xD4													);
	RF_WRITE_CMD(CMD_AFC		|AFC_POWER_ON|AFC_RANG_8|AFC_ST		|AFC_OE		|AFC_EN	);
	//RF_WRITE_CMD(CMD_TX		|TX_DEV_120	|TX_POWER_0						 			);
	RF_WRITE_CMD(CMD_PLL		|PLL_CLK_25	|PLL_LPX	|PLL_DDIT	|PLL_BW0			);
  	
	while (1)
   	{
		START_FIFO;
      	ChkSum = 0;
     
      	for (i=0;i<16;i++) 
	  	{
	  		b= RF_READ_DATA();
			rx_buf[i]=b;
			ChkSum +=b;
	  	}
	  	b = RF_READ_DATA();
	  	RF_READ_DATA();
		STOP_FIFO;
	  
	  	for (i=0;i<16;i++)
	  	{
	  		put_rs232(rx_buf[i]);
			delay_ms(2);
	  	}
	  	if (ChkSum == b) LED_TRG = ~ LED_TRG;
	  	else put_rs232('\f');
	  	if (LED_TRG) LED_H;
	  	else LED_L;  
   	}
   	return 0;
}