int8_t _bmac_rx()
{
int8_t n;
uint8_t cnt;
rf_set_rx (&bmac_rfRxInfo, g_chan);
rf_polling_rx_on ();
cnt=0;
while ((n = rf_rx_check_fifop()) == 0)
{
cnt++;
nrk_wait(_bmac_check_period);
if(cnt>2) {
#ifdef DEBUG
printf( "rx timeout 1 %d\r\n",cnt );
#endif
if(rx_failure_cnt<65535) rx_failure_cnt++;
rf_rx_off();
return 0;
}
}
if (n != 0) {
n = 0;
// Packet on its way
cnt=0;
while ((n = rf_polling_rx_packet ()) == 0) {
cnt++;
nrk_spin_wait_us(100);
if (cnt > 50) {
#ifdef DEBUG
printf( "rx timeout 2\r\n" );
#endif
rx_failure_cnt++;
rf_rx_off();
return 0;
}
}
}
rf_rx_off();
if (n == 1) {
// CRC and checksum passed
rx_buf_empty=0;
#ifdef DEBUG
printf( "BMAC: SNR= %d [",bmac_rfRxInfo.rssi );
for(uint8_t i=0; i<bmac_rfRxInfo.length; i++ )
printf( "%c", bmac_rfRxInfo.pPayload[i]);
printf( "]\r\n" );
#endif
return 1;
} else
{
#ifdef DEBUG
printf( "CRC failed!\r\n" );
#endif
rx_failure_cnt++;
return 0;
}
rx_failure_cnt++;
return 0;
}
void _isa_rx (uint8_t slot)
{
uint8_t n;
uint32_t node_mask;
volatile uint8_t timeout;
#ifdef LED_DEBUG
nrk_led_set(1);
#endif
rf_set_rx (&isa_rfRxInfo, isa_param.channel); // sets rx buffer and channel
rf_polling_rx_on ();
// Timing for waiting for sfd
timeout = _nrk_os_timer_get();
timeout+=4; // 4ms
n = 0;
//nrk_gpio_set(NRK_DEBUG_3);
while ((n = rf_rx_check_sfd()) == 0) {
if (_nrk_os_timer_get() > timeout) {
//spend too much time on waiting for a pkt's arrival
rf_rx_off ();
#ifdef LED_DEBUG
nrk_led_clr(1);
#endif
#ifdef RX_DEBUG
printf("sfd times out.\n\r");
#endif
return;
}
}
//printf("%d\n\r",_nrk_high_speed_timer_get());
// sfd received, start receiving packet and record start time
rx_start_time = _nrk_high_speed_timer_get();
// Timing for waiting for finishing packet receiving
timeout = _nrk_os_timer_get();
timeout += 5; // 5ms
if (n != 0) {
n = 0;
//printf("Packet on its way\n\r");
while ((n = rf_polling_rx_packet (false,128)) == 0) {
//printf("%d\n\r",_nrk_os_timer_get());
if (_nrk_os_timer_get () > timeout) {
#ifdef RX_DEBUG
printf("packet is too long, times out.\n\r");
#endif
// spend too much time on receiving pkt.
return; // huge timeout as fail safe
}
}
}
rf_rx_off ();
if (n == 1) {// successfully received packet
isa_rx_data_ready = 1;
//potential problem: if repeater or recipient receives noise, the DHDR would be changed. And it is highly possible that the highest bit of DHDR would be set to 0
/*if(isa_node_mode != ISA_GATEWAY)
DHDR = isa_rfRxInfo.pPayload[DHDR_INDEX];*/
#ifdef RX_DEBUG
printf("Repeater slot = %d, local slot is %d.\n\r", isa_rfRxInfo.pPayload[SLOT_INDEX],global_slot);
#endif RX_DEBUG
nrk_event_signal(isa_rx_pkt_signal);
//_nrk_high_speed_timer_reset();
//nrk_high_speed_timer_wait(0,CPU_PROCESS_TIME);
//nrk_gpio_set(NRK_DEBUG_3);
node_mask = ((uint32_t) 1) << isa_rfRxInfo.pPayload[SRC_INDEX];
if( !(node_mask & child_list))
return; //FIXME change
// ACK required
if(DHDR & (1<<7)){
// Transmit ACK packet
DHR = configDHR();
isa_ack_buf[DHR_INDEX]= DHR;
#ifdef ACK_DEBUG
//printf("DHR is %d.\n\r",DHR);
#endif
isa_ack_tx.pPayload = isa_ack_buf;
if (DHDR & (1<<2)){ // recipient , only reply explicit ACK
//isa_ack_tx.length = PKT_DATA_START-1;
isa_ack_tx.length = 2;
}
else { //reply ACK with time offsetX
offsetX = rx_start_time - slot_start_time;
//printf("slot_start_time is %d,rx_start_time is %d.\n\r",slot_start_time,rx_start_time);
uint8_t temp1,temp2;
temp1 = (offsetX & 0xFF00)>>8;
isa_ack_buf[OFFSET_HIGH]=temp1;
temp2 = (offsetX & 0x00FF);
isa_ack_buf[OFFSET_LOW]=temp2;
#ifdef ACK_DEBUG
printf("offsetX is %d\n\r", offsetX);
#endif
//isa_ack_tx.length = PKT_DATA_START + 1;
isa_ack_tx.length = 4;
}
rf_tx_tdma_packet (&isa_ack_tx,slot_start_time,isa_param.tx_guard_time,&tx_start_time);
}
