/**************************************************************************************************
* @fn MRFI_Init
*
* @brief Initialize MRFI.
*
* @param none
*
* @return none
**************************************************************************************************
*/
void MRFI_Init(void)
{
/* Configure Output lines */
MRFI_CONFIG_RESETN_PIN_AS_OUTPUT();
MRFI_CONFIG_VREG_EN_PIN_AS_OUTPUT();
/* Configure Input lines */
MRFI_CONFIG_TX_FRAME_DONE_AS_INPUT();
MRFI_CONFIG_FIFO_AS_INPUT();
MRFI_CONFIG_FIFOP_AS_INPUT();
/* Initialize SPI */
mrfiSpiInit();
/* Power up the radio chip */
Mrfi_TurnOnRadioPower();
/* Confirm that we are talking to the right hardware */
MRFI_ASSERT(mrfiSpiReadReg(CHIPID) == MRFI_RADIO_PARTNUM);
/* Random Number Generator:
* The seed value for the randon number generator logic
* is derived from the radio.
*/
/* Set radio in rx mode, but with symbol search disabled. Used for RSSI
* measurments or when we don't care about the received frames.
*/
mrfiSpiWriteReg(FRMCTRL0, FRMCTRL0_RESET_VALUE | RX_MODE_RSSI_ONLY);
/* Turn on the receiver */
mrfiSpiCmdStrobe(SRXON);
/*
* Wait for RSSI to be valid. RANDOM command strobe can be used
* to generate random number only after this.
*/
MRFI_RSSI_VALID_WAIT();
/* Get random byte from the radio */
mrfiRndSeed = mrfiSpiRandomByte();
/*
* The seed value must not be zero. If it is, the pseudo random sequence
* will be always be zero. There is an extremely small chance this seed could
* randomly be zero (more likely some type of hardware problem would cause
* this). If it is zero, initialize it to something.
*/
if(mrfiRndSeed == 0)
{
mrfiRndSeed = 0x80;
}
/* Random number initialization is done. Turn the radio off */
Mrfi_TurnOffRadioPower();
/* Initial radio state is - OFF state */
mrfiRadioState = MRFI_RADIO_STATE_OFF;
/**********************************************************************************
* Compute reply delay scalar
*
* The IEEE radio has a fixed data rate of 250 Kbps. Data rate inference
* from radio regsiters is not necessary for this radio.
*
* The maximum delay needed depends on the MAX_APP_PAYLOAD parameter. Figure
* out how many bits that will be when overhead is included. Bits/bits-per-second
* is seconds to transmit (or receive) the maximum frame. We multiply this number
* by 1000 to find the time in milliseconds. We then additionally multiply by
* 10 so we can add 5 and divide by 10 later, thus rounding up to the number of
* milliseconds. This last won't matter for slow transmissions but for faster ones
* we want to err on the side of being conservative and making sure the radio is on
* to receive the reply. The semaphore monitor will shut it down. The delay adds in
* a fudge factor that includes processing time on peer plus lags in Rx and processing
* time on receiver's side.
*
* **********************************************************************************
*/
#define PLATFORM_FACTOR_CONSTANT 2
#define PHY_PREAMBLE_SYNC_BYTES 8
{
uint32_t bits, dataRate = 250000;
bits = ((uint32_t)((PHY_PREAMBLE_SYNC_BYTES + MRFI_MAX_FRAME_SIZE)*8))*10000;
/* processing on the peer + the Tx/Rx time plus more */
sReplyDelayScalar = PLATFORM_FACTOR_CONSTANT + (((bits/dataRate)+5)/10);
}
/* Random delay: This prevents devices on the same power source from repeated
* transmit collisions on power up.
*/
Mrfi_RandomBackoffDelay();
BSP_ENABLE_INTERRUPTS();
}
/**************************************************************************************************
* @fn MRFI_Init
*
* @brief Initialize MRFI.
*
* @param none
*
* @return none
**************************************************************************************************
*/
void MRFI_Init(void)
{
/* ------------------------------------------------------------------
* Initialization
* -----------------
*/
/* initialize radio state variables */
mrfiRxFilterEnabled = 0;
mrfiRadioIsSleeping = 0;
mrfiTxActive = 0;
mrfiRxActive = 0;
/* initialize GPIO pins */
MRFI_CONFIG_GDO0_PIN_AS_INPUT();
MRFI_CONFIG_GDO2_PIN_AS_INPUT();
/* initialize SPI */
mrfiSpiInit();
/* ------------------------------------------------------------------
* Radio power-up reset
* ----------------------
*/
MRFI_ASSERT(MRFI_SPI_CSN_IS_HIGH());
/* pulse CSn low then high */
MRFI_SPI_DRIVE_CSN_LOW();
MRFI_DELAY(10);
MRFI_SPI_DRIVE_CSN_HIGH();
/* hold CSn high for at least 40 microseconds */
MRFI_DELAY(100);
/* pull CSn low and wait for SO to go low */
MRFI_SPI_DRIVE_CSN_LOW();
while (MRFI_SPI_SO_IS_HIGH());
/* directly send strobe command - cannot use function as it affects CSn pin */
MRFI_SPI_WRITE_BYTE(MRFI_CC2500_SPI_STROBE_SRES);
MRFI_SPI_WAIT_DONE();
/* wait for SO to go low again, reset is complete at that point */
while (MRFI_SPI_SO_IS_HIGH());
/* return CSn pin to its default high level */
MRFI_SPI_DRIVE_CSN_HIGH();
/* ------------------------------------------------------------------
* Run-time integrity checks
* ---------------------------
*/
/* verify that SPI is working */
#ifdef MRFI_ASSERTS_ARE_ON
#define TEST_VALUE 0xA5
mrfiSpiWriteReg( MRFI_CC2500_SPI_REG_PKTLEN, TEST_VALUE );
MRFI_ASSERT( mrfiSpiReadReg( MRFI_CC2500_SPI_REG_PKTLEN ) == TEST_VALUE ); /* SPI is not responding */
#endif
/* verify the correct radio is installed */
MRFI_ASSERT( mrfiSpiReadReg( MRFI_CC2500_SPI_REG_PARTNUM ) == MRFI_RADIO_PARTNUM); /* incorrect radio specified */
MRFI_ASSERT( mrfiSpiReadReg( MRFI_CC2500_SPI_REG_VERSION ) >= MRFI_RADIO_MIN_VERSION); /* obsolete radio specified */
/* ------------------------------------------------------------------
* Configure radio
* -----------------
*/
/* initialize radio registers */
{
uint8_t i;
for (i=0; i<(sizeof(mrfiRadioCfg)/sizeof(mrfiRadioCfg[0])); i++)
{
mrfiSpiWriteReg(mrfiRadioCfg[i][0], mrfiRadioCfg[i][1]);
}
}
/* send strobe to turn on receiver */
mrfiSpiCmdStrobe(MRFI_CC2500_SPI_STROBE_SRX);
/* ------------------------------------------------------------------
* Configure interrupts
* ----------------------
*/
/*
* Configure and enable the SYNC signal interrupt.
*
* This interrupt is used to indicate receive. The SYNC signal goes
* high when a receive OR a transmit begins. It goes high once the
* sync word is received or transmitted and then goes low again once
* the packet completes.
*/
MRFI_CONFIG_SYNC_PIN_FALLING_EDGE_INT();
MRFI_CLEAR_SYNC_PIN_INT_FLAG();
MRFI_ENABLE_SYNC_PIN_INT();
/* configure PA_PD signal interrupt */
MRFI_CONFIG_PAPD_FALLING_EDGE_INT();
/* enable global interrupts */
BSP_ENABLE_INTERRUPTS();
}
