int8_t _bmac_tx() { uint8_t v,backoff, backoff_count; uint16_t b; #ifdef DEBUG nrk_kprintf( PSTR("_bmac_tx()\r\n")); #endif if(cca_active) { // Add random time here to stop nodes from synchronizing with eachother b=_nrk_time_to_ticks(&_bmac_check_period); b=b/((rand()%10)+1); //printf( "waiting %d\r\n",b ); nrk_wait_until_ticks(b); //nrk_wait_ticks(b); backoff_count=1; do{ v=_bmac_channel_check(); rf_rx_off(); if(v==1) break; // Channel is busy backoff=rand()%(_b_pow(backoff_count)); #ifdef DEBUG printf( "backoff %d\r\n",backoff ); #endif // printf( "backoff %d\r\n",backoff ); nrk_wait_until_next_n_periods(backoff); backoff_count++; if(backoff_count>6) backoff_count=6; // cap it at 64 b=_nrk_time_to_ticks(&_bmac_check_period); b=b/((rand()%10)+1); // printf( "waiting %d\r\n",b ); nrk_wait_until_ticks(b); // nrk_wait_ticks(b); } while(v==0); } rf_test_mode(); rf_carrier_on(); nrk_wait(_bmac_check_period); //nrk_wait_until_next_period(); rf_carrier_off(); rf_data_mode(); // send packet rf_rx_off(); pkt_got_ack=rf_tx_packet (&bmac_rfTxInfo); rf_rx_off(); tx_data_ready=0; nrk_event_signal (bmac_tx_pkt_done_signal); return NRK_OK; }
int8_t _bmac_tx() { uint8_t v,result, backoff, backoff_count; uint16_t b; if(cca_active) { // Add random time here to stop nodes from synchronizing with eachother b=_nrk_time_to_ticks(&_bmac_check_period); b=b/((rand()%10)+1); //printf( "waiting %d\r\n",b ); nrk_wait_until_ticks(b); //nrk_wait_ticks(b); backoff_count=1; do { v=_bmac_channel_check(); rf_rx_off(); if(v==1) break; // Channel is busy backoff=rand()%(_b_pow(backoff_count)); // printf( "backoff %d\r\n",backoff ); nrk_wait_until_next_n_periods(backoff); backoff_count++; if(backoff_count>6) backoff_count=6; // cap it at 64 b=_nrk_time_to_ticks(&_bmac_check_period); b=b/((rand()%10)+1); // printf( "waiting %d\r\n",b ); nrk_wait_until_ticks(b); // nrk_wait_ticks(b); } while(v==0); } // Give check_period worth of channel activity rf_test_mode(); rf_carrier_on(); nrk_wait(_bmac_check_period); rf_carrier_off(); rf_data_mode(); rf_rx_off(); pkt_got_ack = rf_tx_packet(&bmac_rfTxInfo); rf_rx_off(); tx_data_ready = 0; // Should signal user task here that Tx is done return NRK_OK; }