LOCAL void RF24_irqHandler(void)
{
if (RF24_receiveCallback) {
// Will stay for a while (several 100us) in this interrupt handler. Any interrupts from serial
// rx coming in during our stay will not be handled and will cause characters to be lost.
// As a workaround we re-enable interrupts to allow nested processing of other interrupts.
// Our own handler is disconnected to prevent recursive calling of this handler.
#if defined(MY_GATEWAY_SERIAL) && !defined(__linux__)
detachInterrupt(digitalPinToInterrupt(MY_RF24_IRQ_PIN));
interrupts();
#endif
// Read FIFO until empty.
// Procedure acc. to datasheet (pg. 63):
// 1.Read payload, 2.Clear RX_DR IRQ, 3.Read FIFO_status, 4.Repeat when more data available.
// Datasheet (ch. 8.5) states, that the nRF de-asserts IRQ after reading STATUS.
// Start checking if RX-FIFO is not empty, as we might end up here from an interrupt
// for a message we've already read.
while (RF24_isDataAvailable()) {
RF24_receiveCallback(); // Must call RF24_readMessage(), which will clear RX_DR IRQ !
}
// Restore our interrupt handler.
#if defined(MY_GATEWAY_SERIAL) && !defined(__linux__)
noInterrupts();
attachInterrupt(digitalPinToInterrupt(MY_RF24_IRQ_PIN), RF24_irqHandler, FALLING);
#endif
} else {
// clear RX interrupt
RF24_setStatus(_BV(RF24_RX_DR));
}
}
LOCAL bool RF24_sendMessage(const uint8_t recipient, const void* buf, const uint8_t len)
{
uint8_t RF24_status;
RF24_stopListening();
RF24_openWritingPipe( recipient );
RF24_DEBUG(PSTR("RF24:SND:TO=%d,LEN=%d\n"),recipient,len); // send message
// flush TX FIFO
RF24_flushTX();
// this command is affected in clones (e.g. Si24R1): flipped NoACK bit when using W_TX_PAYLOAD_NO_ACK / W_TX_PAYLOAD
// AutoACK is disabled on the broadcasting pipe - NO_ACK prevents resending
RF24_spiMultiByteTransfer(recipient == BROADCAST_ADDRESS ? RF24_WRITE_TX_PAYLOAD_NO_ACK :
RF24_WRITE_TX_PAYLOAD, (uint8_t*)buf, len, false );
// go, TX starts after ~10us
RF24_ce(HIGH);
// timeout counter to detect HW issues
uint16_t timeout = 0xFFFF;
do {
RF24_status = RF24_getStatus();
} while (!(RF24_status & ( _BV(RF24_MAX_RT) | _BV(RF24_TX_DS) )) && timeout--);
// timeout value after successful TX on 16Mhz AVR ~ 65500, i.e. msg is transmitted after ~36 loop cycles
RF24_ce(LOW);
// reset interrupts
RF24_setStatus(_BV(RF24_TX_DS) | _BV(RF24_MAX_RT) );
// Max retries exceeded
if(RF24_status & _BV(RF24_MAX_RT)) {
// flush packet
RF24_DEBUG(PSTR("!RF24:SND:MAX_RT\n")); // max retries, no ACK
RF24_flushTX();
}
RF24_startListening();
// true if message sent
return (RF24_status & _BV(RF24_TX_DS));
}
LOCAL uint8_t RF24_readMessage( void* buf) {
const uint8_t len = RF24_getDynamicPayloadSize();
RF24_DEBUG(PSTR("RF24:read message, len=%d\n"), len);
RF24_spiMultiByteTransfer( R_RX_PAYLOAD , (uint8_t*)buf, len, true );
// clear RX interrupt
RF24_setStatus(_BV(RX_DR) );
return len;
}
LOCAL bool RF24_initialize(void) {
// Initialize pins
pinMode(MY_RF24_CE_PIN,OUTPUT);
pinMode(MY_RF24_CS_PIN,OUTPUT);
// Initialize SPI
_SPI.begin();
RF24_ce(LOW);
RF24_csn(HIGH);
// CRC and power up
RF24_setRFConfiguration(MY_RF24_CONFIGURATION | _BV(PWR_UP) ) ;
// settle >2ms
delay(5);
// set address width
RF24_setAddressWidth(MY_RF24_ADDR_WIDTH);
// auto retransmit delay 1500us, auto retransmit count 15
RF24_setRetries(RF24_ARD, RF24_ARC);
// set channel
RF24_setChannel(MY_RF24_CHANNEL);
// set data rate and pa level
RF24_setRFSetup(MY_RF24_RF_SETUP);
// sanity check
#if defined(MY_RF24_SANITY_CHECK)
if (!RF24_sanityCheck()) {
RF24_DEBUG(PSTR("RF24:Sanity check failed: configuration mismatch! Check wiring, replace module or non-P version\n"));
return false;
}
#endif
// toggle features (necessary on some clones)
RF24_enableFeatures();
// enable ACK payload and dynamic payload
RF24_setFeature(MY_RF24_FEATURE);
// enable broadcasting pipe
RF24_setPipe(_BV(ERX_P0 + BROADCAST_PIPE));
// disable AA on all pipes, activate when node pipe set
RF24_setAutoACK(0x00);
// enable dynamic payloads on used pipes
RF24_setDynamicPayload(_BV(DPL_P0 + BROADCAST_PIPE) | _BV(DPL_P0));
// listen to broadcast pipe
MY_RF24_BASE_ADDR[0] = BROADCAST_ADDRESS;
RF24_setPipeAddress(RX_ADDR_P0 + BROADCAST_PIPE, (uint8_t*)&MY_RF24_BASE_ADDR, BROADCAST_PIPE > 1 ? 1 : MY_RF24_ADDR_WIDTH);
// pipe 0, set full address, later only LSB is updated
RF24_setPipeAddress(RX_ADDR_P0, (uint8_t*)&MY_RF24_BASE_ADDR, MY_RF24_ADDR_WIDTH);
RF24_setPipeAddress(TX_ADDR, (uint8_t*)&MY_RF24_BASE_ADDR, MY_RF24_ADDR_WIDTH);
// reset FIFO
RF24_flushRX();
RF24_flushTX();
// reset interrupts
RF24_setStatus(_BV(TX_DS) | _BV(MAX_RT) | _BV(RX_DR));
return true;
}