/**************************************************************************************************
* @fn MRFI_Sleep
*
* @brief Request radio go to sleep.
*
* @param none
*
* @return zero : if successfully went to sleep
* non-zero : if sleep was not entered
**************************************************************************************************
*/
uint8_t MRFI_Sleep(void)
{
/* if radio is already asleep just indicate radio went to sleep successfully */
if (mrfiRadioIsSleeping)
{
/* return value of zero indicates sleep state was entered */
return( 0 );
}
/* determine if sleep is possible and return the corresponding code */
{
bspIState_t s;
/* critical section necessary for watertight testing and setting of state variables */
BSP_ENTER_CRITICAL_SECTION(s);
if (!mrfiTxActive && !mrfiRxActive)
{
mrfiRadioIsSleeping = 1;
MRFI_DISABLE_SYNC_PIN_INT();
mrfiSpiCmdStrobe(MRFI_CC2500_SPI_STROBE_SIDLE);
mrfiSpiCmdStrobe(MRFI_CC2500_SPI_STROBE_SPWD);
BSP_EXIT_CRITICAL_SECTION(s);
/* return value of zero indicates sleep state was entered */
return( 0 );
}
else
{
BSP_EXIT_CRITICAL_SECTION(s);
/* return value of non-zero indicates sleep state was *not* entered */
return( 1 );
}
}
}
void radioISR(void)
{
unsigned int coreIntSource = RF1AIV; // Radio Core interrupt register
// Radio Core interrupt
if(coreIntSource)
{
// Check for SYNC interrupt
if(coreIntSource == RF1AIV_RFIFG9)
{
if(MRFI_SYNC_PIN_INT_IS_ENABLED())
{
static CCPACKET ccPacket;
/* clear the sync pin interrupt, run sync pin ISR */
/*
* NOTE! The following macro clears the interrupt flag but it also *must*
* reset the interrupt capture. In other words, if a second interrupt
* occurs after the flag is cleared it must be processed, i.e. this interrupt
* exits then immediately starts again. Most microcontrollers handle this
* naturally but it must be verified for every target.
*/
MRFI_CLEAR_SYNC_PIN_INT_FLAG();
MRFI_DISABLE_SYNC_PIN_INT();
// Any packet waiting to be read?
if (panstamp.radio.receiveData(&ccPacket) > 0)
{
// Is CRC OK?
if (ccPacket.crc_ok)
{
if (panstamp.ccPacketReceived != NULL)
panstamp.ccPacketReceived(&ccPacket);
}
MRFI_ENABLE_SYNC_PIN_INT();
}
}
}
// Check for RF_RDY (Event1 WOR) interrupt
else if(coreIntSource == RF1AIV_RFIFG14)
{
RF1AIE |= BIT9 + BIT1;
RF1AIFG &= ~(BIT9 + BIT1);
RF1AIES |= BIT9; // Falling edge of RFIFG9
panstamp.radio.setRxState();
__bic_SR_register_on_exit(LPM3_bits);
}
}
}
/**
* rxOff
*
* Disable RF reception
*/
void PANSTAMP::rxOff(void)
{
MRFI_DISABLE_SYNC_PIN_INT();
}
/**************************************************************************************************
* @fn MRFI_Transmit
*
* @brief Transmit a packet using CCA algorithm.
*
* @param pPacket - pointer to packet to transmit
*
* @return Return code indicates success or failure of transmit:
* MRFI_TRANSMIT_SUCCESS - transmit succeeded
* MRFI_TRANSMIT_CCA_FAILED - transmit failed because of CCA check(s)
* MRFI_TRANSMIT_RADIO_ASLEEP - transmit failed because radio was asleep
**************************************************************************************************
*/
uint8_t MRFI_Transmit(mrfiPacket_t * pPacket)
{
uint8_t ccaRetries;
uint8_t txBufLen;
uint8_t savedSyncIntState;
uint8_t returnValue;
/* abort transmit if radio is asleep */
{
bspIState_t s;
/* critical section necessary for watertight testing and setting of state variables */
BSP_ENTER_CRITICAL_SECTION(s);
/* if radio is asleep, abort transmit and return reason for failure */
if (mrfiRadioIsSleeping)
{
BSP_EXIT_CRITICAL_SECTION(s);
return( MRFI_TRANSMIT_RADIO_ASLEEP );
}
/* radio is not asleep, set flag that indicates transmit is active */
mrfiTxActive = 1;
BSP_EXIT_CRITICAL_SECTION(s);
}
/* set number of CCA retries */
ccaRetries = MRFI_CCA_RETRIES;
/* compute number of bytes to write to transmit FIFO */
txBufLen = pPacket->frame[MRFI_LENGTH_FIELD_OFS] + MRFI_LENGTH_FIELD_SIZE;
/* write packet to transmit FIFO */
mrfiSpiWriteTxFifo(&(pPacket->frame[0]), txBufLen);
/* ===============================================================================
* Main Loop
* =============
*/
for (;;)
{
/* CCA delay */
MRFI_DELAY(2000);
/* disable sync pin interrupts, necessary because both transmit and receive affect sync signal */
MRFI_DISABLE_SYNC_PIN_INT();
/* store the sync pin interrupt flag, important so original state can be restored */
savedSyncIntState = MRFI_SYNC_PIN_INT_FLAG_IS_SET();
/*
* Clear the PA_PD pin interrupt flag. This flag, not the interrupt itself,
* is used to capture the transition that indicates a transmit was started.
* The pin level cannot be used to indicate transmit success as timing may
* prevent the transition from being detected. The interrupt latch captures
* the event regardless of timing.
*/
MRFI_CLEAR_PAPD_PIN_INT_FLAG();
/* send strobe to initiate transmit */
mrfiSpiCmdStrobe(MRFI_CC2500_SPI_STROBE_STX);
/* delay long enough for the PA_PD signal to indicate a successful transmit */
MRFI_DELAY(250);
/* if the interrupt flag of the PA_PD pin is set, CCA passed and the transmit has started */
if (MRFI_PAPD_INT_FLAG_IS_SET())
{
/* ------------------------------------------------------------------
* Clear Channel Assessment passed.
* ----------------------------------
*/
/* wait for transmit to complete */
while (!MRFI_PAPD_PIN_IS_HIGH());
/*
* Restore the original sync interrupt state. The successful transmit just
* caused a transition on the sync signal that set the flag (if not already
* set). To restore the original state, the flag is simply cleared if it
* was clear earlier.
*/
if (!savedSyncIntState)
{
MRFI_CLEAR_SYNC_PIN_INT_FLAG();
}
/* transmit complete, enable sync pin interrupts */
MRFI_ENABLE_SYNC_PIN_INT();
/* set return value for successful transmit and break */
returnValue = MRFI_TRANSMIT_SUCCESS;
break;
}
/* ------------------------------------------------------------------
* Clear Channel Assessment failed.
* ----------------------------------
*/
/* CCA failed, safe to enable sync pin interrupts */
MRFI_ENABLE_SYNC_PIN_INT();
/* if no CCA retries are left, transmit failed so abort */
if (ccaRetries == 0)
{
bspIState_t s;
/*
* Flush the transmit FIFO. It must be flushed so that
* the next transmit can start with a clean slate.
* Critical section prevents receive interrupt from
* occurring in the middle of clean-up.
*/
BSP_ENTER_CRITICAL_SECTION(s);
mrfiSpiCmdStrobe(MRFI_CC2500_SPI_STROBE_SIDLE);
mrfiSpiCmdStrobe(MRFI_CC2500_SPI_STROBE_SFTX);
mrfiSpiCmdStrobe(MRFI_CC2500_SPI_STROBE_SRX);
BSP_EXIT_CRITICAL_SECTION(s);
/* set return value for failed transmit and break */
returnValue = MRFI_TRANSMIT_CCA_FAILED;
break;
}
/* decrement CCA retries before loop continues */
ccaRetries--;
}
/*
* =============================================================================== */
mrfiTxActive = 0;
return( returnValue );
}
