main.c

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

RFM02-Funkmodul (Empfangen)

-----------------------

ATMEGA168PA       RFM01

-----------------------

XCK (PD4).........SCK

TXD (PD1).........SDI

PD7...............nSEL

RXD (PD0).........SDO

PB1...............nIRQ

PD3...............nFFS

PB5...............LED

PD2...............Module-Power

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

#include <avr/io.h>

#include <util/delay.h>

#include <avr/interrupt.h>

#define DDR_XCK DDRD

#define XCK 4

#define DDR_LED DDRB

#define LED 5

#define DDR_BLED DDRC

#define BLED 0

#define DDR_MODULE DDRD

#define MODULE_POWER 2

#define DDR_nSEL DDRD

#define nSEL 7

#define DDR_nIRQ DDRB

#define nIRQ 1

#define DDR_nFFS DDRD

#define nFFS 3

#define LED_ON() PORTB |= (1<<LED)

#define LED_OFF() PORTB &= ~(1<<LED)

#define BLED_ON() PORTC |= (1<<BLED)

#define BLED_OFF() PORTC &= ~(1<<BLED)

#define MODULE_ON() PORTD |= (1<<MODULE_POWER)

#define MODULE_OFF() PORTD &= ~(1<<MODULE_POWER)

#define nSEL_HIGH() PORTD |= (1<<nSEL)

#define nSEL_LOW() PORTD &= ~(1<<nSEL)

#define nIRQ_HIGH() PINB&(1<<nIRQ)

#define nIRQ_LOW() !(PINB&(1<<nIRQ))

#define nFFS_HIGH() PORTD |= (1<<nFFS)

#define nFFS_LOW() PORTD &= ~(1<<nFFS)

#define FOSC 8000000 // Clock Speed

#define BAUD 1000

#define MYUBRR FOSC/(2*BAUD)-1

void init_gpio()

{

  // Initialize On-Board LED on PB5

  LED_OFF();

  DDR_LED |= (1<<LED);

  BLED_OFF();

  DDR_BLED |= (1<<BLED);

  // Initialize Module Power

  MODULE_OFF();

  DDR_MODULE |= (1<<MODULE_POWER);

  // Initialize nFFS FIFO Select

  nFFS_LOW();

  DDR_nFFS |= (1<<nFFS);

  // Initialize nSEL

  nSEL_LOW();

  DDR_nSEL |= (1<<nSEL);

  // Initialize nIRQ (Input)

  // Deactivate internal Pull-Up

  PORTB &= ~(1<<nIRQ);

  DDR_nIRQ &= ~(1<<nIRQ);

}

void init_usart_as_spi_for_cmd(unsigned int ubrr)

{

  // SPI MODE 0 -> Data sheet page 197

  // This mode is used to transmit commands

  // Disable transmitter and receiver

  UCSR0B &= ~((1<<TXEN0) | (1<<RXEN0));

  //Choose Baud Rate to zero for initialization

  UBRR0 = 0;

  // First: Activate the Clock Generation

  DDR_XCK |=(1<<XCK);

  // Use USART0 in Master SPI Mode (MSPIM)

  UCSR0C |= (1<<UMSEL01) | (1<<UMSEL00);

  // Define SPI Data Order, Clock Phase and Clock Polarity

  // Data Order of RF02: MSB first

  UCSR0C &= ~(1<<UCSZ01);

  // SPI Mode 0 (I found it out with data sheets)

  // Clock Phase: Data shifted in RF02 on Rising Edge of SCK

  UCSR0C &= ~(1<<UCSZ00);

  // Clock Polarity: Low is idle status

  UCSR0C &= ~(1<<UCPOL0);

  // Enable transmitter and receiver

  UCSR0B |= (1<<TXEN0) | (1<<RXEN0);

  //UCSR0B |= (1<<TXEN0);

  // Set Baud Rate

  //UBRR0 = MYUBRR;

  UBRR0 = 4095;

  // Data Register Empty Interrupt Enable

  //UCSR0B |= (1<<TXCIE0) | (1<<RXCIE0);

  //UCSR0B |= (1<<UDRIE0);

  //sei();

}

void init_usart_as_spi_for_read(unsigned int ubrr)

{

  // SPI MODE 1 -> Data sheet page 197

  // This mode is used to read status or received data

  // Disable transmitter and receiver

  UCSR0B &= ~((1<<TXEN0) | (1<<RXEN0));

  //Choose Baud Rate to zero for initialization

  UBRR0 = 0;

  // First: Activate the Clock Generation

  DDR_XCK |=(1<<XCK);

  // Use USART0 in Master SPI Mode (MSPIM)

  UCSR0C |= (1<<UMSEL01) | (1<<UMSEL00);

  // Define SPI Data Order, Clock Phase and Clock Polarity

  // Data Order of RF02: MSB first

  UCSR0C &= ~(1<<UCSZ01);

  // SPI Mode 1 (I found it out with data sheets)

  // Clock Phase: Data shifted out of RF01 on Falling Edge of SCK

  UCSR0C |= (1<<UCSZ00);

  // Clock Polarity: Low is idle status

  UCSR0C &= ~(1<<UCPOL0);

  // Enable transmitter and receiver

  UCSR0B |= (1<<TXEN0) | (1<<RXEN0);

  //UCSR0B |= (1<<TXEN0);

  // Set Baud Rate

  //UBRR0 = MYUBRR;

  UBRR0 = 4095;

  // Data Register Empty Interrupt Enable

  //UCSR0B |= (1<<TXCIE0) | (1<<RXCIE0);

  //UCSR0B |= (1<<UDRIE0);

  //sei();

}

void view_byte(uint8_t byte)

{

  unsigned wait = 700;

  for (int bit=0;bit<8;bit++)

  {

    LED_ON();

    if ((byte & 0b00000001)==0) BLED_OFF();

    else BLED_ON();

    _delay_ms(wait);

    LED_OFF();

    _delay_ms(wait);

    byte = byte>>1;

  }

  BLED_OFF();

}

void error()

{

  for (int i=0; i<20;i++)

  {

    LED_ON();

    _delay_ms(50);

    LED_OFF();

    _delay_ms(50);

  }

}

uint8_t receive_usart()

{

  if( UCSR0A & (1<<RXC0) ) return UDR0;

  else

  {

    error();

    return 0;

  }

}

void transmitCmd(uint16_t cmd)

{

  // Clear TXC0 flag for new transmission. It is not cleared automatically because no transmit complete interrupt is executed.

  // Clearing this bit by writing a one to its bit location <--- Yes, its true!

  UCSR0A |= (1<<TXC0);

  nSEL_LOW();

  uint8_t byteToSend = 0;

  // Wait for empty transmit buffer

  while ( !(UCSR0A & (1<<UDRE0)) );

  byteToSend = (cmd & 0b1111111100000000)>>8;

  UDR0 = byteToSend;

  // Wait for empty transmit buffer

  while ( !(UCSR0A & (1<<UDRE0)) );

  byteToSend = (cmd & 0b0000000011111111);

  UDR0 = byteToSend;

  //while ( !(UCSR0A & (1<<RXC0)) ) LED_ON();

  //LED_OFF();

  //_delay_ms(100);

  /* Get and return received data from buffer */

  while(!(UCSR0A & (1<<TXC0)));

  _delay_ms(1);

  nSEL_HIGH();

  // Wait for data to be received

  //while ( !(UCSR0A & (1<<RXC0)) );

  // Get and return received data from buffer

  //return UDR0;

}

/*

void transmitData(uint16_t data)

{

  uint8_t irq = 0;

  while(nIRQ_HIGH());

  for (int bit=0;bit<8;bit++)

  {

    if(data & 0b10000000) HIGH_BIT();

    else LOW_BIT();

    data = data<<1;

    if (nIRQ_LOW()) irq &= ~(1<<bit);

    while(nIRQ_LOW());

    if (nIRQ_HIGH()) irq |= (1<<bit);

    while(nIRQ_HIGH());

  }

  view_byte(irq);

}

*/

void clearTXBuffer()

{

  uint8_t tmp;

  while (UCSR0A & (1<<RXC0)) tmp = UDR0;

}

void init_rf01()

{

  // nFFS High recommended by data sheet

  nFFS_HIGH();

  // Switch on RF01

  MODULE_ON();

  // Initialize Module

  nSEL_HIGH();

}

void heartbeat()

{

  //LED_ON();

  BLED_ON();

  _delay_ms(200);

  //LED_OFF();

  BLED_OFF();

  _delay_ms(200);

  //LED_ON();

  BLED_ON();

  _delay_ms(200);

  //LED_OFF();

  BLED_OFF();

  _delay_ms(200);

}

int main(void)

{

  init_gpio();

  _delay_ms(1000);  

  init_rf01();

  heartbeat();

  _delay_ms(1000);

  uint8_t dataReceived = 0;

  /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

  ////////////////////////////////////////////////////////////// COMMANDS /////////////////////////////////////////////////////////////

  /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

  //  1: Configuration Setting Command: Frequency band, low battery detector, wake-up timer, crystal oscillator load capacitance, baseband filter bandwidth, clock output

  // 100 (CMD) 01 (433 MHz) 00 (Low Batteery Det Off) 1 (Crystal On During Sleep Mode) 1000 (x3-x0 Crystal Load Cap) 101 (Baseband Bandwidth) 0 (dc)

  uint16_t configSetCmd = 0b1000100110001010;

  //  2: Frequency Setting Command: Set the frequency of the local oscillator

  // 1010 (CMD) 0110 0100 0000 (F) -> f0 = 10 MHz * 1 * (43 + 1600(F)/4000) = 434 MHz

  // F = 96 to 3903

  uint16_t freqSetCmd = 0b1010011001000000;

  //  3: Receiver Setting Command: Set VDI source, LNA gain, RSSI threshold

  // 1100 0000 (CMD) 10 (Valid Data Indicator VDI Output) 00 (LNA Gain) 000 (RSSI Threshold) 0 (Enable Receiver Chain)

  uint16_t receiverSetCmd = 0b1100000010000000;

  uint16_t enableReceiverCmd = 0b1100000010000001;

  //  4: Wake-Up Timer Command: Wake-up time period

  uint16_t wakeUpTimerCmd = 0;

  //  5: Low Duty-Cycle Command: Set duty-cycle, enable low duty-cycle mode

  uint16_t lowDutyCycleCmd = 0;

  //  6: Low Battery Detector and Clock Divider Command: Set LBD threshold voltage and microcontroller clock division ratio

  // 1100 0010 (CMD) 010 (d2-d0 Clk Output Frequency) 00000 (t4-t0 Low Battery Threshold Voltage) -> V = 2.25V + T*0.1V

  uint16_t lowBatClockDivCmd = 0b1100001001000000;

  //  7: AFC Control Command: Set AFC parameters

  // 1100 0110 (CMD) 10 (Automatic Operation) 01 (Frequency Offset Limit) 1 (Strobe Edge) 0 (High accuracy mode) 1 (Output frequency offset register) 1 (Calculate offset frequency)

  uint16_t afcControlCmd = 0b1100011010011011;

  //  8: Data Filter Command: Set data filter type, clock recovery parameters

  // 1100 0100 (CMD) 0 (Clk Recovery Auto Lock Control) 0 (Clk Recovery Lock Control) 1 (x) 01 (Filter Type) 010 (f2-f0 DQD Threshold Parameter)

  uint16_t dataFilterCmd = 0b1100010000101010;

  //  9: Data Rate Command: Bit rate

  // 1100 1000 (CMD) 0 (cs) 100 0111 (R) -> BR = 10 MHz / 29 / (R+1) / (1+cs*7) = 10 MHz / 29 / (71+1) / (1+0*7) = 4,789 kbps

  // Data rate = 600 bps to 115,2 kbps

  uint16_t dataRateCmd = 0b1100100001000111;

  // 10: Output and FIFO Command: Set FIFO IT level, FIFO start control, FIFO enable and FIFO fill enable

  // 1100 1110 (CMD) 1000 (f3-f0 FIFO Interrupt IT Level) 01 (FIFO Fill Start Condition) 0 (Enables FIFO Fill After Synchron Word Reception) 0 (Enables 16 bit Deep FIFO Mode)

  uint16_t outputFifoCmd = 0b1100111010000100;

  uint16_t enableFifoCmd = 0b1100111010000111;

  // 11: Reset Mode Command: Enable / disable sensitive reset

  uint16_t resetModeCmd = 0;

  // 12: Status Register Command: Read status information

  uint16_t statusReadCmd = 0b0000000000000000;

  /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

  ////////////////////////////////////////////////////////// Configure RF02 ///////////////////////////////////////////////////////////

  /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

  uint16_t wait = 250;

  //transmitCmd(statusReadCmd);

  //dataReceived = receive_usart();

  //if(dataReceived != 0) view_byte(dataReceived);

  //dataReceived = receive_usart();

  //if(dataReceived != 0) view_byte(dataReceived);

/*

  //_delay_ms(wait);

  heartbeat();

  transmitCmd(configSetCmd);

  clearTXBuffer();

  //_delay_ms(wait);

  heartbeat();

  transmitCmd(freqSetCmd);

  clearTXBuffer();

  //_delay_ms(wait);

  heartbeat();

  transmitCmd(dataRateCmd);

  clearTXBuffer();

  //_delay_ms(wait);

  heartbeat();

  transmitCmd(afcControlCmd);

  clearTXBuffer();

  //_delay_ms(wait);

  heartbeat();

  transmitCmd(dataFilterCmd);

  clearTXBuffer();

  //_delay_ms(wait);

  heartbeat();

  transmitCmd(lowBatClockDivCmd);

  clearTXBuffer();

  //_delay_ms(wait);

  heartbeat();

  transmitCmd(receiverSetCmd);

  clearTXBuffer();

  //_delay_ms(wait);

  heartbeat();

  transmitCmd(outputFifoCmd);

  clearTXBuffer();

  //_delay_ms(wait);

  heartbeat();

  transmitCmd(enableFifoCmd);

  clearTXBuffer();

  //_delay_ms(wait);

  heartbeat();

  transmitCmd(enableReceiverCmd);

  clearTXBuffer();  

  */

  /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

  /////////////////////////////////////////////////////// Start Transmission //////////////////////////////////////////////////////////

  /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

  //_delay_ms(wait*4);

  init_usart_as_spi_for_cmd(MYUBRR);

  //transmitCmd(outputFifoCmd);

  //clearTXBuffer();

  while(1)

  {

    BLED_ON();

    _delay_ms(2000);

    BLED_OFF();

    _delay_ms(2000);

    transmitCmd(statusReadCmd);

    clearTXBuffer();

    /*

    if(dataReceived != 0) view_byte(dataReceived);

    dataReceived = receive_usart();

    if(dataReceived != 0) view_byte(dataReceived);

    */

  //transmitCmd(statusReadCmd);

  //clearTXBuffer();

  /*

    //dataReceived = receive_usart();

    //_delay_ms(2000);

    LED_ON();

    _delay_ms(2000);

    transmitCmd(powerManagementCmd);

    // Wait for PLL and Crystal Start

    _delay_ms(10);

    //_delay_ms(wait);

    transmitData(0b1010101010101010);

    //_delay_ms(wait);

    transmitCmd(standbyCmd);

    LED_OFF();

    _delay_ms(2000);

    heartbeat();

    _delay_ms(2000);

    */

  };

}

ISR (USART_TX_vect)

{

}

ISR (USART_RX_vect)

{

}