static int nrf_driver_send(void* p, int len)
{
/**
* Air time is 1 byte preamble, 5 byte address, 2 byte CRC and 9 bits at the end.
* We add 25 just to make sure we satisfy air time requirement.
* The slots is the number of slots we allocate for someone to send their data,
* and we pick one of them to avoid data collision when nodes repeat a packet.
*/
static const uint32_t s_pkt_air_time_us =
25 + (((8 * (MESH_PAYLOAD + 1 + 5 + 3)) * 1000) / WIRELESS_AIR_DATARATE_KBPS);
const uint32_t slots = MESH_MAX_NODES;
int packetWasSent = 1;
/**
* If we are not the source of this packet, that means we are repeating the packet.
* If we are repeating the packet to discover the route (mac.dst == MESH_ZERO_ADDR)
* then we need to randomly pick one air-time slot otherwise if all nodes send at
* the same time, then their data will collide and packet won't go through.
*/
const mesh_packet_t *pkt = (mesh_packet_t*)p;
if (mesh_get_node_address() != pkt->nwk.src) {
if (MESH_ZERO_ADDR == pkt->mac.dst) {
const uint32_t timeSlotDelayUs = ((rand() % slots) + 1) * s_pkt_air_time_us;
delay_us(timeSlotDelayUs); /**< Maximize mesh nodes to repeat the packet and not collide */
}
}
// Bring from RX mode to TX mode
nordic_rx_to_Stanby1();
nordic_standby1_to_tx_mode1();
// Send the packet :
nordic_mode1_send_single_packet(p, len);
nordic_clear_packet_sent_flag();
// Switch back to receive mode
nordic_standby1_to_rx();
/* If FreeRTOS is running, we are probably blocked indefinitely on the activity semaphore.
* So we will give the semaphore here, to give the mesh network task to unblock and
* carry out retry logic. We use FromISR() API such that mesh_send() will not be
* restricted to be called from a FreeRTOS task alone.
*/
if (taskSCHEDULER_RUNNING == xTaskGetSchedulerState()) {
xSemaphoreGiveFromISR(g_nrf_activity_sem, NULL);
}
return packetWasSent;
}
// TO DO:
void nordic_finishTxMode2_transitionToStandby1(char* data, unsigned short length)
{
// Wait until any previous Tx Packets are sent such that Nordic will be in Standby-1 mode.
while(!nordic_is_tx_fifo_empty());
// From Standby-1 or Standby-2, filling FIFO goes to "Tx Settling" State.
// Set CE to low while Nordic is in "Tx Setting" state.
nordic_mode1_send_single_packet(data, length);
// After packet is sent, Nordic will enter STANDBY-1 since CE is low
while(NORDIC_INT_SIGNAL());
//while(!nordic_isTxFifoEmpty());
nordic_clear_packet_sent_flag();
}
