// Called when the radio has received a packet.
static void anchor_rxcallback (const dwt_callback_data_t *rxd) {
if (rxd->event == DWT_SIG_RX_OKAY) {
// Read in parameters of this packet reception
uint64_t dw_rx_timestamp;
uint8_t buf[ONEWAY_ANCHOR_MAX_RX_PKT_LEN];
uint8_t message_type;
// Get the received time of this packet first
dwt_readrxtimestamp(buf);
dw_rx_timestamp = DW_TIMESTAMP_TO_UINT64(buf);
// Get the actual packet bytes
dwt_readrxdata(buf, MIN(ONEWAY_ANCHOR_MAX_RX_PKT_LEN, rxd->datalength), 0);
// We process based on the first byte in the packet. How very active
// message like...
message_type = buf[offsetof(struct pp_tag_poll, message_type)];
if (message_type == MSG_TYPE_PP_NOSLOTS_TAG_POLL) {
// This is one of the broadcast ranging packets from the tag
struct pp_tag_poll* rx_poll_pkt = (struct pp_tag_poll*) buf;
// Decide what to do with this packet
if (_state == ASTATE_IDLE) {
// We are currently not ranging with any tags.
if (rx_poll_pkt->subsequence < NUM_RANGING_CHANNELS) {
// We are idle and this is one of the first packets
// that the tag sent. Start listening for this tag's
// ranging broadcast packets.
_state = ASTATE_RANGING;
// Clear memory for this new tag ranging event
memset(pp_anc_final_pkt.TOAs, 0, sizeof(pp_anc_final_pkt.TOAs));
memset(_anchor_antenna_recv_num, 0, sizeof(_anchor_antenna_recv_num));
// Record the EUI of the tag so that we don't get mixed up
memcpy(pp_anc_final_pkt.ieee154_header_unicast.destAddr, rx_poll_pkt->header.sourceAddr, 8);
// Record which ranging subsequence the tag is on
_ranging_broadcast_ss_num = rx_poll_pkt->subsequence;
// Record the timestamp. Need to subtract off the TX+RX delay from each recorded
// timestamp.
pp_anc_final_pkt.TOAs[_ranging_broadcast_ss_num] =
dw_rx_timestamp - oneway_get_txrxdelay_from_subsequence(ANCHOR, _ranging_broadcast_ss_num);
// Also record parameters the tag has sent us about how to respond
// (or other operational parameters).
_ranging_operation_config.reply_after_subsequence = rx_poll_pkt->reply_after_subsequence;
_ranging_operation_config.anchor_reply_window_in_us = rx_poll_pkt->anchor_reply_window_in_us;
_ranging_operation_config.anchor_reply_slot_time_in_us = rx_poll_pkt->anchor_reply_slot_time_in_us;
// Update the statistics we keep about which antenna
// receives the most packets from the tag
uint8_t recv_antenna_index = oneway_subsequence_number_to_antenna(ANCHOR, rx_poll_pkt->subsequence);
_anchor_antenna_recv_num[recv_antenna_index]++;
// Now we need to start our own state machine to iterate
// through the antenna / channel combinations while listening
// for packets from the same tag.
timer_start(_anchor_timer, RANGING_BROADCASTS_PERIOD_US, ranging_broadcast_subsequence_task);
} else {
// We found this tag ranging sequence late. We don't want
// to use this because we won't get enough range estimates.
// Just stay idle, but we do need to re-enable RX to
// keep receiving packets.
dwt_rxenable(0);
}
} else if (_state == ASTATE_RANGING) {
// We are currently ranging with a tag, waiting for the various
// ranging broadcast packets.
// First check if this is from the same tag
if (memcmp(pp_anc_final_pkt.ieee154_header_unicast.destAddr, rx_poll_pkt->header.sourceAddr, 8) == 0) {
// Same tag
if (rx_poll_pkt->subsequence == _ranging_broadcast_ss_num) {
// This is the packet we were expecting from the tag.
// Record the TOA, and adjust it with the calibration value.
pp_anc_final_pkt.TOAs[_ranging_broadcast_ss_num] =
dw_rx_timestamp - oneway_get_txrxdelay_from_subsequence(ANCHOR, _ranging_broadcast_ss_num);
// Update the statistics we keep about which antenna
// receives the most packets from the tag
uint8_t recv_antenna_index = oneway_subsequence_number_to_antenna(ANCHOR, _ranging_broadcast_ss_num);
_anchor_antenna_recv_num[recv_antenna_index]++;
} else {
// Some how we got out of sync with the tag. Ignore the
// range and catch up.
_ranging_broadcast_ss_num = rx_poll_pkt->subsequence;
}
// Check to see if we got the last of the ranging broadcasts
if (_ranging_broadcast_ss_num == _ranging_operation_config.reply_after_subsequence) {
// We did!
ranging_listening_window_setup();
}
} else {
// Not the same tag, ignore
}
} else {
// We are in some other state, not sure what that means
}
} else {
// Other message types go here, if they get added
// We do want to enter RX mode again, however
dwt_rxenable(0);
}
} else {
// Called when the radio has received a packet.
void dw1000_anchor_rxcallback (const dwt_callback_data_t *rxd) {
if (rxd->event == DWT_SIG_RX_OKAY) {
// Read in parameters of this packet reception
uint64_t dw_rx_timestamp;
uint8_t buf[DW1000_ANCHOR_MAX_RX_PKT_LEN];
uint8_t message_type;
// Get the received time of this packet first
dwt_readrxtimestamp(buf);
dw_rx_timestamp = DW_TIMESTAMP_TO_UINT64(buf);
// Get the actual packet bytes
dwt_readrxdata(buf, MIN(DW1000_ANCHOR_MAX_RX_PKT_LEN, rxd->datalength), 0);
// We process based on the first byte in the packet. How very active
// message like...
message_type = buf[offsetof(struct pp_tag_poll, message_type)];
if (message_type == MSG_TYPE_PP_NOSLOTS_TAG_POLL) {
// This is one of the broadcast ranging packets from the tag
struct pp_tag_poll* rx_poll_pkt = (struct pp_tag_poll*) buf;
// Decide what to do with this packet
if (_state == ASTATE_IDLE) {
// We are currently not ranging with any tags.
if (rx_poll_pkt->subsequence < NUM_RANGING_CHANNELS) {
// We are idle and this is one of the first packets
// that the tag sent. Start listening for this tag's
// ranging broadcast packets.
_state = ASTATE_RANGING;
// Clear memory for this new tag ranging event
memset(pp_anc_final_pkt.TOAs, 0, sizeof(pp_anc_final_pkt.TOAs));
memset(_anchor_antenna_recv_num, 0, sizeof(_anchor_antenna_recv_num));
// Record the EUI of the tag so that we don't get mixed up
memcpy(pp_anc_final_pkt.ieee154_header_unicast.destAddr, rx_poll_pkt->header.sourceAddr, 8);
// Record which ranging subsequence the tag is on
_ranging_broadcast_ss_num = rx_poll_pkt->subsequence;
// Record the timestamp
pp_anc_final_pkt.TOAs[_ranging_broadcast_ss_num] = dw_rx_timestamp;
// Also record parameters the tag has sent us about how to respond
// (or other operational parameters).
_ranging_operation_config.reply_after_subsequence = rx_poll_pkt->reply_after_subsequence;
_ranging_operation_config.anchor_reply_window_in_us = rx_poll_pkt->anchor_reply_window_in_us;
_ranging_operation_config.anchor_reply_slot_time_in_us = rx_poll_pkt->anchor_reply_slot_time_in_us;
// Update the statistics we keep about which antenna
// receives the most packets from the tag
uint8_t recv_antenna_index = subsequence_number_to_antenna(ANCHOR, rx_poll_pkt->subsequence);
_anchor_antenna_recv_num[recv_antenna_index]++;
// Now we need to start our own state machine to iterate
// through the antenna / channel combinations while listening
// for packets from the same tag.
_ranging_broadcast_ss_num++;
dw1000_set_ranging_broadcast_subsequence_settings(ANCHOR, _ranging_broadcast_ss_num, FALSE);
timer_start(_ranging_broadcast_timer, RANGING_BROADCASTS_PERIOD_US, ranging_broadcast_subsequence_task);
} else {
// We found this tag ranging sequence late. We don't want
// to use this because we won't get enough range estimates.
// Just stay idle.
}
} else if (_state == ASTATE_RANGING) {
// We are currently ranging with a tag, waiting for the various
// ranging broadcast packets.
// First check if this is from the same tag
if (memcmp(pp_anc_final_pkt.ieee154_header_unicast.destAddr, rx_poll_pkt->header.sourceAddr, 8) == 0) {
// Same tag
if (rx_poll_pkt->subsequence == _ranging_broadcast_ss_num) {
// This is the packet we were expecting from the tag.
// Record the TOA.
pp_anc_final_pkt.TOAs[_ranging_broadcast_ss_num] = dw_rx_timestamp;
// Update the statistics we keep about which antenna
// receives the most packets from the tag
uint8_t recv_antenna_index = subsequence_number_to_antenna(ANCHOR, _ranging_broadcast_ss_num);
_anchor_antenna_recv_num[recv_antenna_index]++;
} else {
// Some how we got out of sync with the tag. Ignore the
// range and catch up.
_ranging_broadcast_ss_num = rx_poll_pkt->subsequence;
}
// Check to see if we got the last of the ranging broadcasts
if (_ranging_broadcast_ss_num == _ranging_operation_config.reply_after_subsequence) {
// We did!
// Stop iterating through timing channels
timer_stop(_ranging_broadcast_timer);
// We no longer need to receive and need to instead
// start transmitting.
dwt_forcetrxoff();
// Update our state to the TX response state
_state = ASTATE_RESPONDING;
// Set the listening window index
_ranging_listening_window_num = 0;
// Determine which antenna we are going to use for
// the response.
uint8_t max_packets = 0;
uint8_t max_index = 0;
for (uint8_t i=0; i<NUM_ANTENNAS; i++) {
if (_anchor_antenna_recv_num[i] > max_packets) {
max_packets = _anchor_antenna_recv_num[i];
max_index = i;
}
}
pp_anc_final_pkt.final_antenna = max_index;
// Now we need to setup a timer to iterate through
// the response windows so we can send a packet
// back to the tag
timer_start(_ranging_broadcast_timer,
_ranging_operation_config.anchor_reply_window_in_us,
ranging_listening_window_task);
}
} else {
// Not the same tag, ignore
}
} else {
// We are in some other state, not sure what that means
}
} else {
// Other message types go here, if they get added
}
} else {
