AMiRo-OS

/*! ----------------------------------------------------------------------------

 *  @file    instance_tag.c

 *  @brief   Decawave tag application state machine for TREK demo

 *

 * @attention

 *

 * Copyright 2016 (c) Decawave Ltd, Dublin, Ireland.

 *

 * All rights reserved.

 *

 * @author Decawave

 */

#include <alld_DW1000.h>

#include <deca_instance.h>

#include <string.h>

#include <math.h>

#include <module.h>

// -------------------------------------------------------------------------------------------------------------------

//

// function to construct the message/frame header bytes

//

// -------------------------------------------------------------------------------------------------------------------

//

void instanceconfigframeheader16(instance_data_t *inst){

  //set frame type (0-2), SEC (3), Pending (4), ACK (5), PanIDcomp(6)

  inst->msg_f.frameCtrl[0] = 0x1 /*frame type 0x1 == data*/ | 0x40 /*PID comp*/;

  //source/dest addressing modes and frame version

  inst->msg_f.frameCtrl[1] = 0x8 /*dest extended address (16bits)*/ | 0x80 /*src extended address (16bits)*/;

  inst->msg_f.panID[0] = (inst->panID) & 0xff;

  inst->msg_f.panID[1] = inst->panID >> 8;

  inst->msg_f.seqNum = 0;

}

int instancesenddlypacket(instance_data_t *inst, int delayedTx){

  int result = 0;

  dwt_writetxfctrl(inst->psduLength, 0, 1);

  if(delayedTx == DWT_START_TX_DELAYED){

    dwt_setdelayedtrxtime(inst->delayedReplyTime) ; //should be high 32-bits of delayed TX TS

  }

  //begin delayed TX of frame

  if (dwt_starttx((uint8_t)(delayedTx | inst->wait4ack))){ // delayed start was too late

    result = 1; //late/error

    inst->lateTX++;

  }

  else {

    inst->timeofTx = portGetTickCnt();

    inst->monitor = 1;

  }

  return result;                                              // state changes

}

int instance_calcranges(uint32_t *array, uint16_t size, int reportRange, uint8_t* mask){

  int i;

  int newRange = TOF_REPORT_NUL;

  int distance = 0;

  for(i=0; i<size; i++)  {

    uint32_t tofx = array[i];

    if(tofx != INVALID_TOF) { //if ToF == 0 - then no new range to report

      distance = reportTOF(i, tofx);

    }

    if(distance == 1){

      newRange = reportRange;

    }

    else {

      //clear mask

      *mask &= ~(0x1 << i) ;

      clearDistTable(i);

    }

    array[i] = INVALID_TOF;

    distance = 0;

  }

  return newRange;

}

// -------------------------------------------------------------------------------------------------------------------

//

// the main instance state machine (all the instance modes Tag, Anchor or Listener use the same statemachine....)

//

// -------------------------------------------------------------------------------------------------------------------

//

int testapprun(instance_data_t *inst, int message){

  switch (inst->testAppState){

  case TA_INIT :

    // printf("TA_INIT") ;

    switch (inst->mode) {

    case TAG: {

      uint16_t sleep_mode = 0;

      dwt_enableframefilter(DWT_FF_DATA_EN | DWT_FF_ACK_EN); //allow data, ack frames;

      dwt_setpanid(inst->panID);

      memcpy(inst->eui64, &inst->instanceAddress16, ADDR_BYTE_SIZE_S);

      dwt_seteui(inst->eui64);

      //set source address

      inst->newRangeTagAddress = inst->instanceAddress16 ;

      dwt_setaddress16(inst->instanceAddress16);

      //Start off by Sleeping 1st -> set instToSleep to TRUE

      inst->nextState = TA_TXPOLL_WAIT_SEND;

      inst->testAppState = TA_TXE_WAIT;

      inst->instToSleep = TRUE ;

      inst->rangeNum = 0;

      inst->tagSleepCorrection = 0;

      sleep_mode = (DWT_LOADUCODE|DWT_PRESRV_SLEEP|DWT_CONFIG|DWT_TANDV);

      if(inst->configData.txPreambLength == DWT_PLEN_64)  //if using 64 length preamble then use the corresponding OPSet

        sleep_mode |= DWT_LOADOPSET;

#if (DEEP_SLEEP == 1)

      dwt_configuresleep(sleep_mode, DWT_WAKE_WK|DWT_WAKE_CS|DWT_SLP_EN); //configure the on wake parameters (upload the IC config settings)

#endif

      instanceconfigframeheader16(inst);

      inst->instanceWakeTime = portGetTickCnt();

    }

    break;

    case ANCHOR: {

      memcpy(inst->eui64, &inst->instanceAddress16, ADDR_BYTE_SIZE_S);

      dwt_seteui(inst->eui64);

      dwt_setpanid(inst->panID);

      //set source address

      inst->shortAdd_idx = (inst->instanceAddress16 & 0x3) ;

      dwt_setaddress16(inst->instanceAddress16);

      //if address = 0x8000

      if(inst->instanceAddress16 == GATEWAY_ANCHOR_ADDR){

        inst->gatewayAnchor = TRUE;

      }

      dwt_enableframefilter(DWT_FF_NOTYPE_EN); //allow data, ack frames;

      // First time anchor listens we don't do a delayed RX

      dwt_setrxaftertxdelay(0);

      //change to next state - wait to receive a message

      inst->testAppState = TA_RXE_WAIT ;

      dwt_setrxtimeout(0);

      dwt_setpreambledetecttimeout(0);

      instanceconfigframeheader16(inst);

    }

    break;

    case LISTENER:{

      dwt_enableframefilter(DWT_FF_NOTYPE_EN); //disable frame filtering

      dwt_setrxaftertxdelay(0); //no delay of turning on of RX

      dwt_setrxtimeout(0);

      dwt_setpreambledetecttimeout(0);

      //change to next state - wait to receive a message

      inst->testAppState = TA_RXE_WAIT ;

    }

    break ; // end case TA_INIT

    default:

      break;

    }

    break; // end case TA_INIT

    case TA_SLEEP_DONE : {

      event_data_t* dw_event = instance_getevent(10); //clear the event from the queue

      // waiting for timout from application to wakup IC

      if (dw_event->type != DWT_SIG_RX_TIMEOUT){

        // if no pause and no wake-up timeout continu waiting for the sleep to be done.

        inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT; //wait here for sleep timeout

        break;

      }

      inst->done = INST_NOT_DONE_YET;

      inst->instToSleep = FALSE ;

      inst->testAppState = inst->nextState;

      inst->nextState = 0; //clear

      inst->instanceWakeTime = portGetTickCnt(); // Record the time count when we wake-up

#if (DEEP_SLEEP == 1)

      {

        uint32 x = 0;

        //wake up device from low power mode

        //NOTE - in the ARM  code just drop chip select for 200us

        led_on(LED_PC9);

        port_SPIx_clear_chip_select();  //CS low

        instance_data[0].dwIDLE = 0; //reset DW1000 IDLE flag

        setup_DW1000RSTnIRQ(1); //enable RSTn IRQ

        Sleep(2);   //200 us to wake up - need 2 as Sleep(1) is ~ 175 us

//        chThdSleepMilliseconds(2);

        //then wait 5ms for DW1000 XTAL to stabilise - instead of wait we wait for RSTn to go high

        //Sleep(5);

        //need to poll to check when the DW1000 is in IDLE, the CPLL interrupt is not reliable

        //when RSTn goes high the DW1000 is in INIT, it will enter IDLE after PLL lock (in 5 us)

        while(instance_data[0].dwIDLE == 0) // this variable will be sent in the IRQ (process_dwRSTn_irq)

        {

          //wait for DW1000 to go to IDLE state RSTn pin to go high

          x++;

        }

        setup_DW1000RSTnIRQ(0); //disable RSTn IRQ

        port_SPIx_set_chip_select();  //CS high

        //!!! NOTE it takes ~35us for the DW1000 to download AON and lock the PLL and be in IDLE state

        //do some dummy reads of the dev ID register to make sure DW1000 is in IDLE before setting LEDs

        x = dwt_readdevid(); //dummy read... need to wait for 5 us to exit INIT state (5 SPI bytes @ ~18 MHz)

        x = dwt_readdevid(); //dummy read... need to wait for 5 us to exit INIT state (5 SPI bytes @ ~18 MHz)

        x = dwt_readdevid(); //dummy read... need to wait for 5 us to exit INIT state (5 SPI bytes @ ~18 MHz)

        x = dwt_readdevid(); //dummy read... need to wait for 5 us to exit INIT state (5 SPI bytes @ ~18 MHz)

        x = dwt_readdevid(); //dummy read... need to wait for 5 us to exit INIT state (5 SPI bytes @ ~18 MHz)

        /*if(x != DWT_DEVICE_ID)

                {

                    x = dwt_readdevid(); //dummy read... need to wait for 5 us to exit INIT state (5 SPI bytes @ ~18 MHz)

                }*/

        led_off(LED_PC9);

        //this is platform dependent - only program if DW EVK/EVB

        dwt_setleds(1);

        //MP bug - TX antenna delay needs reprogramming as it is not preserved (only RX)

        dwt_settxantennadelay(inst->txAntennaDelay) ;

        //set EUI as it will not be preserved unless the EUI is programmed and loaded from NVM

        dwt_seteui(inst->eui64);

      }

#else

      Sleep(3); //to approximate match the time spent in the #if above

#endif

      instancesetantennadelays(); //this will update the antenna delay if it has changed

      instancesettxpower(); //configure TX power if it has changed

    }

    break;

    case TA_TXE_WAIT : //either go to sleep or proceed to TX a message

      // printf("TA_TXE_WAIT") ;

      //if we are scheduled to go to sleep before next transmission then sleep first.

      if((inst->nextState == TA_TXPOLL_WAIT_SEND)

          && (inst->instToSleep)  //go to sleep before sending the next poll/ starting new ranging exchange

      ){

        inst->rangeNum++; //increment the range number before going to sleep

        //the app should put chip into low power state and wake up after tagSleepTime_ms time...

        //the app could go to *_IDLE state and wait for uP to wake it up...

        inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT_TO; //don't sleep here but kick off the Sleep timer countdown

        inst->testAppState = TA_SLEEP_DONE; {

#if (DEEP_SLEEP == 1)

          //put device into low power mode

          dwt_entersleep(); //go to sleep

#endif

          //DW1000 gone to sleep - report the received range

          inst->newRange = instance_calcranges(&inst->tofArray[0], MAX_ANCHOR_LIST_SIZE, TOF_REPORT_T2A, &inst->rxResponseMask);

          inst->rxResponseMaskReport = inst->rxResponseMask;

          inst->rxResponseMask = 0;

          inst->newRangeTime = portGetTickCnt() ;

        }

      }

      else {  //proceed to configuration and transmission of a frame

        inst->testAppState = inst->nextState;

        inst->nextState = 0; //clear

      }

      break ; // end case TA_TXE_WAIT

    case TA_TXPOLL_WAIT_SEND : {

      inst->msg_f.messageData[POLL_RNUM] = (inst->mode == TAG) ? inst->rangeNum : inst->rangeNumAnc; //copy new range number

      inst->msg_f.messageData[FCODE] = (inst->mode == TAG) ? RTLS_DEMO_MSG_TAG_POLL : RTLS_DEMO_MSG_ANCH_POLL; //message function code (specifies if message is a poll, response or other...)

      inst->psduLength = (TAG_POLL_MSG_LEN + FRAME_CRTL_AND_ADDRESS_S + FRAME_CRC);

      inst->msg_f.seqNum = inst->frameSN++; //copy sequence number and then increment

      inst->msg_f.sourceAddr[0] = inst->eui64[0]; //copy the address

      inst->msg_f.sourceAddr[1] = inst->eui64[1]; //copy the address

      inst->msg_f.destAddr[0] = 0xff;  //set the destination address (broadcast == 0xffff)

      inst->msg_f.destAddr[1] = 0xff;  //set the destination address (broadcast == 0xffff)

      dwt_writetxdata(inst->psduLength, (uint8_t *)  &inst->msg_f, 0) ;        // write the frame data

      //set the delayed rx on time (the response message will be sent after this delay (from A0))

      dwt_setrxaftertxdelay((uint32_t)RX_RESPONSE1_TURNAROUND);  //units are 1.0256us - wait for wait4respTIM before RX on (delay RX)

      if(inst->mode == TAG){

        inst->rxResps[inst->rangeNum] = 0; //reset the number of received responses

        inst->responseTO = MAX_ANCHOR_LIST_SIZE; //expecting 4 responses

        dwt_setrxtimeout((uint16_t)inst->fwtoTime_sy * MAX_ANCHOR_LIST_SIZE);  //configure the RX FWTO

      }

      else {

        inst->rxResps[inst->rangeNumAnc] = 0; //reset number of responses

        inst->responseTO = NUM_EXPECTED_RESPONSES_ANC0; //2 responses A1, A2

        dwt_setrxtimeout((uint16_t)inst->fwtoTime_sy * (NUM_EXPECTED_RESPONSES_ANC0));  //units are

      }

      inst->rxResponseMask = 0;        //reset/clear the mask of received responses when tx poll

      inst->rxResponseMaskAnc = 0;

      inst->wait4ack = DWT_RESPONSE_EXPECTED; //response is expected - automatically enable the receiver

      dwt_writetxfctrl(inst->psduLength, 0, 1); //write frame control

      dwt_starttx(DWT_START_TX_IMMEDIATE | DWT_RESPONSE_EXPECTED); //transmit the frame

      inst->testAppState = TA_TX_WAIT_CONF ;  // wait confirmation

      inst->previousState = TA_TXPOLL_WAIT_SEND ;

      inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT; //will use RX FWTO to time out (set above)

    }

    break;

    case TA_TXFINAL_WAIT_SEND : {

      //the final has the same range number as the poll (part of the same ranging exchange)

      inst->msg_f.messageData[POLL_RNUM] = (inst->mode == TAG) ? inst->rangeNum : inst->rangeNumAnc;

      //the mask is sent so the anchors know whether the response RX time is valid

      inst->msg_f.messageData[VRESP] = (inst->mode == TAG) ? inst->rxResponseMask : inst->rxResponseMaskAnc;

      inst->msg_f.messageData[FCODE] = (inst->mode == TAG) ? RTLS_DEMO_MSG_TAG_FINAL : RTLS_DEMO_MSG_ANCH_FINAL; //message function code (specifies if message is a poll, response or other...)

      inst->psduLength = (TAG_FINAL_MSG_LEN + FRAME_CRTL_AND_ADDRESS_S + FRAME_CRC);

      inst->msg_f.seqNum = inst->frameSN++;

      dwt_writetxdata(inst->psduLength, (uint8_t *)  &inst->msg_f, 0) ;        // write the frame data

      inst->wait4ack = 0; //clear the flag not using wait for response as this message ends the ranging exchange

      if(instancesenddlypacket(inst, DWT_START_TX_DELAYED)) {

        // initiate the re-transmission

        if(inst->mode == TAG){

          inst->testAppState = TA_TXE_WAIT ; //go to TA_TXE_WAIT first to check if it's sleep time

          inst->nextState = TA_TXPOLL_WAIT_SEND ;

        }

        else {

          //A0 - failed to send Final

          //A1 - failed to send Final

          //go back to RX and behave as anchor

          instance_backtoanchor(inst);

        }

        break; //exit this switch case...

      }

      else {

        inst->testAppState = TA_TX_WAIT_CONF;                                               // wait confirmation

        inst->previousState = TA_TXFINAL_WAIT_SEND;

      }

      if(inst->mode == TAG){

        inst->instToSleep = TRUE ;

      }

      inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT; //will use RX FWTO to time out (set above)

    }

    break;

    case TA_TX_WAIT_CONF : {

      //printf("TA_TX_WAIT_CONF %d m%d %d states %08x %08x\n", inst->previousState, message, inst->newReportSent, dwt_read32bitreg(0x19), dwt_read32bitreg(0x0f)) ;

      event_data_t* dw_event = instance_getevent(11); //get and clear this event

      //NOTE: Can get the ACK before the TX confirm event for the frame requesting the ACK

      //this happens because if polling the ISR the RX event will be processed 1st and then the TX event

      //thus the reception of the ACK will be processed before the TX confirmation of the frame that requested it.

      if(dw_event->type != DWT_SIG_TX_DONE) { //wait for TX done confirmation

        if(dw_event->type != 0) {

          if(dw_event->type == DWT_SIG_RX_TIMEOUT){   //got RX timeout - i.e. did not get the response (e.g. ACK)

            //printf("RX timeout in TA_TX_WAIT_CONF (%d)\n", inst->previousState);

            //we need to wait for SIG_TX_DONE and then process the timeout and re-send the frame if needed

            inst->gotTO = 1;

          }

          else{

            inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT;

          }

        }

        inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT;

        break;

      }

      inst->done = INST_NOT_DONE_YET;

      if(inst->previousState == TA_TXFINAL_WAIT_SEND) {

        if(inst->mode == TAG){

          inst->testAppState = TA_TXE_WAIT ;

          inst->nextState = TA_TXPOLL_WAIT_SEND ;

          break;

        }

        else{

          instance_backtoanchor(inst);

        }

      }

      else if (inst->gotTO == 1) { //timeout

        //printf("got TO in TA_TX_WAIT_CONF\n");

        inst_processrxtimeout(inst);

        inst->gotTO = 0;

        inst->wait4ack = 0 ; //clear this

        break;

      }

      else{

        inst->txu.txTimeStamp = dw_event->timeStamp;

        if(inst->previousState == TA_TXPOLL_WAIT_SEND){

          uint64_t tagCalculatedFinalTxTime ;

          // Embed into Final message: 40-bit pollTXTime,  40-bit respRxTime,  40-bit finalTxTime

          if(inst->mode == TAG){

            tagCalculatedFinalTxTime =  (inst->txu.txTimeStamp + inst->pollTx2FinalTxDelay) & MASK_TXDTS;

          }

          else {  //for anchor make the final half the delay ..... (this is ok, as A0 awaits 2 responses)

            tagCalculatedFinalTxTime =  (inst->txu.txTimeStamp + inst->pollTx2FinalTxDelayAnc) & MASK_TXDTS;

          }

          inst->delayedReplyTime = (uint32_t)(tagCalculatedFinalTxTime >> 8); //high 32-bits

          // Calculate Time Final message will be sent and write this field of Final message

          // Sending time will be delayedReplyTime, snapped to ~125MHz or ~250MHz boundary by

          // zeroing its low 9 bits, and then having the TX antenna delay added

          // getting antenna delay from the device and add it to the Calculated TX Time

          tagCalculatedFinalTxTime = tagCalculatedFinalTxTime + inst->txAntennaDelay;

          tagCalculatedFinalTxTime &= MASK_40BIT;

          // Write Calculated TX time field of Final message

          memcpy(&(inst->msg_f.messageData[FTXT]), (uint8_t *)&tagCalculatedFinalTxTime, 5);

          // Write Poll TX time field of Final message

          memcpy(&(inst->msg_f.messageData[PTXT]), (uint8_t *)&inst->txu.tagPollTxTime, 5);

          //change the w4r for the second and remaining anchors to 50 us

          //dwt_setrxaftertxdelay((uint32)RX_RESPONSEX_TURNAROUND);  //units are 1.0256us - wait for wait4respTIM before RX on (delay RX)

        }

        if(inst->previousState == TA_TXRESPONSE_SENT_TORX) {

          inst->previousState = TA_TXRESPONSE_WAIT_SEND ;

        }

        inst->testAppState = TA_RXE_WAIT ;                      // After sending, tag expects response/report, anchor waits to receive a final/new poll

        message = 0;

        //fall into the next case (turn on the RX)

      }

    }

    break ; // end case TA_TX_WAIT_CONF

    case TA_RXE_WAIT : {

      // printf("TA_RXE_WAIT") ;

      if(inst->wait4ack == 0) {  //if this is set the RX will turn on automatically after TX

        //turn RX on

        dwt_rxenable(DWT_START_RX_IMMEDIATE) ;  // turn RX on, without delay

      }

      else{

        inst->wait4ack = 0 ; //clear the flag, the next time we want to turn the RX on it might not be auto

      }

      if (inst->mode != LISTENER){

        inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT; //using RX FWTO

      }

      inst->testAppState = TA_RX_WAIT_DATA;   // let this state handle it

      // end case TA_RXE_WAIT, don't break, but fall through into the TA_RX_WAIT_DATA state to process it immediately.

      if(message == 0) break;

    }

    break;

    case TA_RX_WAIT_DATA :   // Wait RX data

      //printf("TA_RX_WAIT_DATA %d", message) ;

      switch (message){

      //if we have received a DWT_SIG_RX_OKAY event - this means that the message is IEEE data type - need to check frame control to know which addressing mode is used

      case DWT_SIG_RX_OKAY : {

        event_data_t* dw_event = instance_getevent(15); //get and clear this event

        uint8_t  srcAddr[8] = {0,0,0,0,0,0,0,0};

        uint8_t  dstAddr[8] = {0,0,0,0,0,0,0,0};

        int fcode = 0;

        int fn_code = 0;

        //int srclen = 0;

        //int fctrladdr_len;

        uint8_t tof_idx  = 0;

        uint8_t *messageData = NULL;

        inst->stopTimer = 0; //clear the flag, as we have received a message

        // handle 16 and 64 bit source and destination addresses

        switch(dw_event->msgu.frame[1] & 0xCC){

        case 0xCC: //

          memcpy(&srcAddr[0], &(dw_event->msgu.rxmsg_ll.sourceAddr[0]), ADDR_BYTE_SIZE_L);

          memcpy(&dstAddr[0], &(dw_event->msgu.rxmsg_ll.destAddr[0]), ADDR_BYTE_SIZE_L);

          fn_code = dw_event->msgu.rxmsg_ll.messageData[FCODE];

          messageData = &dw_event->msgu.rxmsg_ll.messageData[0];

          //srclen = ADDR_BYTE_SIZE_L;

          //fctrladdr_len = FRAME_CRTL_AND_ADDRESS_L;

          break;

        case 0xC8: //

          memcpy(&srcAddr[0], &(dw_event->msgu.rxmsg_sl.sourceAddr[0]), ADDR_BYTE_SIZE_L);

          memcpy(&dstAddr[0], &(dw_event->msgu.rxmsg_sl.destAddr[0]), ADDR_BYTE_SIZE_S);

          fn_code = dw_event->msgu.rxmsg_sl.messageData[FCODE];

          messageData = &dw_event->msgu.rxmsg_sl.messageData[0];

          //srclen = ADDR_BYTE_SIZE_L;

          //fctrladdr_len = FRAME_CRTL_AND_ADDRESS_LS;

          break;

        case 0x8C: //

          memcpy(&srcAddr[0], &(dw_event->msgu.rxmsg_ls.sourceAddr[0]), ADDR_BYTE_SIZE_S);

          memcpy(&dstAddr[0], &(dw_event->msgu.rxmsg_ls.destAddr[0]), ADDR_BYTE_SIZE_L);

          fn_code = dw_event->msgu.rxmsg_ls.messageData[FCODE];

          messageData = &dw_event->msgu.rxmsg_ls.messageData[0];

          //srclen = ADDR_BYTE_SIZE_S;

          //fctrladdr_len = FRAME_CRTL_AND_ADDRESS_LS;

          break;

        case 0x88: //

          memcpy(&srcAddr[0], &(dw_event->msgu.rxmsg_ss.sourceAddr[0]), ADDR_BYTE_SIZE_S);

          memcpy(&dstAddr[0], &(dw_event->msgu.rxmsg_ss.destAddr[0]), ADDR_BYTE_SIZE_S);

          fn_code = dw_event->msgu.rxmsg_ss.messageData[FCODE];

          messageData = &dw_event->msgu.rxmsg_ss.messageData[0];

          //srclen = ADDR_BYTE_SIZE_S;

          //fctrladdr_len = FRAME_CRTL_AND_ADDRESS_S;

          break;

        }

        if((inst->instToSleep == FALSE) && (inst->mode == LISTENER)){ //update received data, and go back to receiving frames

          //do something with message data (e.g. could extract any ToFs and print them)

          inst->testAppState = TA_RXE_WAIT ;              // wait for next frame

          dwt_setrxaftertxdelay(0);

        }

        else{

          //process ranging messages

          fcode = fn_code;

          tof_idx = srcAddr[0] & 0x3 ;

          switch(fcode){

          case RTLS_DEMO_MSG_ANCH_POLL:

          case RTLS_DEMO_MSG_TAG_POLL: {

            inst->tagPollRxTime = dw_event->timeStamp ; //save Poll's Rx time

            if(fcode == RTLS_DEMO_MSG_TAG_POLL){ //got poll from Tag

              inst->rangeNumA[srcAddr[0]&0x7] = messageData[POLL_RNUM]; //when anchor receives a poll, we need to remember the new range number

            }

            else{ //got poll from Anchor (initiator)

              inst->rangeNumAAnc[tof_idx] = messageData[POLL_RNUM]; //when anchor receives poll from another anchor - save the range number

            }

            if (A1_ANCHOR_ADDR == inst->instanceAddress16) { //this is A1

              if(GATEWAY_ANCHOR_ADDR == (srcAddr[0] | ((uint32_t)(srcAddr[1] << 8)))) { //poll is from A0

                //configure the time A1 will poll A2 (it should be in half slot time from now)

                inst->a1SlotTime = dw_event->uTimeStamp + (inst->slotPeriod);

                //inst->instanceTimerEn = 1; - THIS IS ENABLED BELOW AFTER FINAL

                // - means that if final is not received then A1 will not range to A2

              }

            }

            //the response has been sent - await TX done event

            if(dw_event->type_pend == DWT_SIG_TX_PENDING){

              inst->testAppState = TA_TX_WAIT_CONF;                // wait confirmation

              inst->previousState = TA_TXRESPONSE_SENT_POLLRX ;    //wait for TX confirmation of sent response

            }

            //already re-enabled the receiver

            else if (dw_event->type_pend == DWT_SIG_RX_PENDING){

              //stay in RX wait for next frame...

              //RX is already enabled...

              inst->testAppState = TA_RX_WAIT_DATA ;              // wait for next frame

            }

            else{ //the DW1000 is idle (re-enable from the application level)

              //stay in RX wait for next frame...

              inst->testAppState = TA_RXE_WAIT ;              // wait for next frame

            }

          }

          break; //RTLS_DEMO_MSG_TAG_POLL

          case RTLS_DEMO_MSG_ANCH_RESP2:

          case RTLS_DEMO_MSG_ANCH_RESP:{

            uint8_t currentRangeNum = (messageData[TOFRN] + 1); //current = previous + 1

            if(GATEWAY_ANCHOR_ADDR == (srcAddr[0] | ((uint32_t)(srcAddr[1] << 8)))){ //if response from gateway then use the correction factor

              if(inst->mode == TAG){

                // casting received bytes to int because this is a signed correction -0.5 periods to +1.5 periods

                inst->tagSleepCorrection = (int16_t) (((uint16_t) messageData[RES_TAG_SLP1] << 8) + messageData[RES_TAG_SLP0]);

                inst->tagSleepRnd = 0; // once we have initial response from Anchor #0 the slot correction acts and we don't need this anymore

              }

            }

            //the response has been sent - await TX done event

            if(dw_event->type_pend == DWT_SIG_TX_PENDING) { //anchor received response from anchor ID - 1 so is sending it's response now back to tag

              inst->testAppState = TA_TX_WAIT_CONF;                // wait confirmation

              inst->previousState = TA_TXRESPONSE_SENT_RESPRX ;    //wait for TX confirmation of sent response

            }

            //already re-enabled the receiver

            else if(dw_event->type_pend == DWT_SIG_RX_PENDING) {

              // stay in TA_RX_WAIT_DATA - receiver is already enabled.

            }

            //DW1000 idle - send the final

            else { //if(dw_event->type_pend == DWT_SIG_DW_IDLE)

              if(((TAG == inst->mode) && (inst->rxResponseMask & 0x1)) //if A0's response received send the final

                  || ((A1_ANCHOR_ADDR == inst->instanceAddress16) && (inst->rxResponseMaskAnc & 0x4))

                  || ((GATEWAY_ANCHOR_ADDR == inst->instanceAddress16) && (inst->rxResponseMaskAnc & 0x2)) ) { //if A1's response received

                inst->testAppState = TA_TXFINAL_WAIT_SEND ; // send our response / the final

              }

              else { //go to sleep

                if(TAG == inst->mode){

                  inst->testAppState = TA_TXE_WAIT ; //go to TA_TXE_WAIT first to check if it's sleep time

                  inst->nextState = TA_TXPOLL_WAIT_SEND ;

                  inst->instToSleep = TRUE;

                }

                else {

                  instance_backtoanchor(inst);

                }

              }

            }

            if(fcode == RTLS_DEMO_MSG_ANCH_RESP) { //tag to anchor mode

              if(currentRangeNum == inst->rangeNum) { //these are the previous ranges...

                //copy the ToF and put into array (array holds last 4 ToFs)

                memcpy(&inst->tofArray[(srcAddr[0]&0x3)], &(messageData[TOFR]), 4);

                //check if the ToF is valid, this makes sure we only report valid ToFs

                //e.g. consider the case of reception of response from anchor a1 (we are anchor a2)

                //if a1 got a Poll with previous Range number but got no Final, then the response will have

                //the correct range number but the range will be INVALID_TOF

                if(inst->tofArray[(srcAddr[0]&0x3)] != INVALID_TOF){

                  inst->rxResponseMask |= (0x1 << (srcAddr[0]&0x3));

                }

              }

              else {

                if(inst->tofArray[(srcAddr[0]&0x3)] != INVALID_TOF) {

                  inst->tofArray[(srcAddr[0]&0x3)] = INVALID_TOF;

                }

              }

            }

            else { //anchor to anchor (only gateway processes anchor to anchor ToFs)

              //report the correct set of ranges (ranges from anchors A1, A2 need to match owns range number)

                if((inst->gatewayAnchor)&&(currentRangeNum == inst->rangeNumAnc)) { //these are the previous ranges...

                inst->rangeNumAAnc[0] = inst->rangeNumAnc ;

                //once A0 receives A2's response then it can report the 3 ToFs.

                if(inst->rxResps[inst->rangeNumAnc] == 3)

                  //if(A2_ANCHOR_ADDR == (srcAddr[0] | ((uint32)(srcAddr[1] << 8))))

                {

                  //copy the ToF and put into array, the array should have 3 ToFs A0-A1, A0-A2 and A1-A2

                  memcpy(&inst->tofArrayAnc[(srcAddr[0]+dstAddr[0])&0x3], &(messageData[TOFR]), 4);

                  //calculate all anchor - anchor ranges... and report

                  inst->newRange = instance_calcranges(&inst->tofArrayAnc[0], MAX_ANCHOR_LIST_SIZE, TOF_REPORT_A2A, &inst->rxResponseMaskAnc);

                  inst->rxResponseMaskReport = inst->rxResponseMaskAnc;

                  inst->rxResponseMaskAnc = 0;

                  inst->newRangeTime = dw_event->uTimeStamp ;

                }

                else {

                  //copy the ToF and put into array (array holds last 4 ToFs)

                  memcpy(&inst->tofArrayAnc[(srcAddr[0]+dstAddr[0])&0x3], &(messageData[TOFR]), 4);

                }

              }

            }

          }

          break; //RTLS_DEMO_MSG_ANCH_RESP

          case RTLS_DEMO_MSG_ANCH_FINAL:

          case RTLS_DEMO_MSG_TAG_FINAL: {

            int64_t Rb, Da, Ra, Db ;

            uint64_t tagFinalTxTime  = 0;

            uint64_t tagFinalRxTime  = 0;

            uint64_t tagPollTxTime  = 0;

            uint64_t anchorRespRxTime  = 0;

            int32_t tof = (int32_t)INVALID_TOF;

            double RaRbxDaDb = 0;

            double RbyDb = 0;

            double RayDa = 0;

            uint8_t validResp = messageData[VRESP];

            uint8_t index = RRXT0 + 5*(inst->shortAdd_idx);

            if((RTLS_DEMO_MSG_TAG_FINAL == fcode) &&

                (inst->rangeNumA[srcAddr[0]&0x7] != messageData[POLL_RNUM])) { //Final's range number needs to match Poll's or else discard this message

              inst->testAppState = TA_RXE_WAIT ;              // wait for next frame

              break;

            }

            if((RTLS_DEMO_MSG_ANCH_FINAL == fcode) &&

                (((inst->rangeNumAAnc[tof_idx] != messageData[POLL_RNUM]) //Final's range number needs to match Poll's or else discard this message

                    || inst->gatewayAnchor) //gateway can ignore the Final (from A1 to A2 exchange)

                    || (A3_ANCHOR_ADDR == inst->instanceAddress16))) //A3 does not care about Final from A1 or A0

            {

              inst->testAppState = TA_RXE_WAIT ;              // wait for next frame

              break;

            }

            if (A1_ANCHOR_ADDR == inst->instanceAddress16) { //this is A1

              if(GATEWAY_ANCHOR_ADDR == (srcAddr[0] | ((uint32_t)(srcAddr[1] << 8)))) { //final is from A0

                //ENABLE TIMER ONLY IF FINAL RECEIVED

                inst->instanceTimerEn = 1;

              }

            }

            //output data over USB...

            inst->newRangeAncAddress = inst->instanceAddress16;

            //if we got the final, maybe the tag did not get our response, so

            //we can use other anchors responses/ToF if there are any.. and output..

            //but we cannot calculate new range

            if(((validResp & (0x1<<(inst->shortAdd_idx))) != 0)) {

              // time of arrival of Final message

              tagFinalRxTime = dw_event->timeStamp ; //Final's Rx time

              //printf("FinalRx Timestamp: %4.15e\n", convertdevicetimetosecu(dw_event.timeStamp));

              inst->delayedReplyTime = 0 ;

              // times measured at Tag extracted from the message buffer

              // extract 40bit times

              memcpy(&tagPollTxTime, &(messageData[PTXT]), 5);

              memcpy(&anchorRespRxTime, &(messageData[index]), 5);

              memcpy(&tagFinalTxTime, &(messageData[FTXT]), 5);

              // poll response round trip delay time is calculated as

              // (anchorRespRxTime - tagPollTxTime) - (anchorRespTxTime - tagPollRxTime)

              Ra = (int64_t)((anchorRespRxTime - tagPollTxTime) & MASK_40BIT);

              Db = (int64_t)((inst->txu.anchorRespTxTime - inst->tagPollRxTime) & MASK_40BIT);

              // response final round trip delay time is calculated as

              // (tagFinalRxTime - anchorRespTxTime) - (tagFinalTxTime - anchorRespRxTime)

              Rb = (int64_t)((tagFinalRxTime - inst->txu.anchorRespTxTime) & MASK_40BIT);

              Da = (int64_t)((tagFinalTxTime - anchorRespRxTime) & MASK_40BIT);

              RaRbxDaDb = (((double)Ra))*(((double)Rb))

                                                - (((double)Da))*(((double)Db));

              RbyDb = ((double)Rb + (double)Db);

              RayDa = ((double)Ra + (double)Da);

              tof = (int32_t)(RaRbxDaDb/(RbyDb + RayDa));

            }

            //tag to anchor ranging

            if(RTLS_DEMO_MSG_TAG_FINAL == fcode) {

              inst->newRangeTagAddress = srcAddr[0] + ((uint16_t) srcAddr[1] << 8);

              //time-of-flight

              inst->tof[inst->newRangeTagAddress & 0x7] = (uint32_t)tof;

              //calculate all tag - anchor ranges... and report

              inst->newRange = instance_calcranges(&inst->tofArray[0], MAX_ANCHOR_LIST_SIZE, TOF_REPORT_T2A, &inst->rxResponseMask);

              inst->rxResponseMaskReport = inst->rxResponseMask; //copy the valid mask to report

              inst->rxResponseMask = 0;

              //we have our range - update the own mask entry...

              if(tof != (int32_t)INVALID_TOF) { //check the last ToF entry is valid and copy into the current array

                setTagDist(srcAddr[0], inst->shortAdd_idx); //copy distance from this anchor to the tag into array

                inst->rxResponseMask = (uint8_t)(0x1 << inst->shortAdd_idx);

                inst->tofArray[inst->shortAdd_idx] = (uint32_t)tof;

              }

              inst->newRangeTime = dw_event->uTimeStamp ;

            }

            else { //anchor to anchor ranging

              inst->newRangeTagAddress = srcAddr[0] + ((uint16_t) srcAddr[1] << 8);

              //time-of-flight

              inst->tofAnc[tof_idx] = (uint32_t)tof;

            }

            //reset the response count

            if(inst->rxResps[inst->rxRespsIdx] >= 0) {

              inst->rxResps[inst->rxRespsIdx] = -1 * inst->rxResps[inst->rxRespsIdx];

              if(inst->rxResps[inst->rxRespsIdx] == 0) //as A0 will have this as 0 when ranging to A1

                inst->rxResps[inst->rxRespsIdx] = -1 ;

            }

            instancesetantennadelays(); //this will update the antenna delay if it has changed

            instancesettxpower(); // configure TX power if it has changed

            inst->testAppState = TA_RXE_WAIT ;              // wait for next frame

          }

          break; //RTLS_DEMO_MSG_TAG_FINAL

          default: {

            //only enable receiver when not using double buffering

            inst->testAppState = TA_RXE_WAIT ;              // wait for next frame

            dwt_setrxaftertxdelay(0);

          }

          break;

          } //end switch (fcode)

          if(dw_event->msgu.frame[0] & 0x20){

            //as we only pass the received frame with the ACK request bit set after the ACK has been sent

            instance_getevent(16); //get and clear the ACK sent event

          }

        } //end else

      }

      break ; //end of DWT_SIG_RX_OKAY

      case DWT_SIG_RX_TIMEOUT :{

        event_data_t* dw_event = instance_getevent(17); //get and clear this event

        //printf("PD_DATA_TIMEOUT %d\n", inst->previousState) ;

        //Anchor can time out and then need to send response - so will be in TX pending

        if(dw_event->type_pend == DWT_SIG_TX_PENDING) {

          inst->testAppState = TA_TX_WAIT_CONF;                                               // wait confirmation

          inst->previousState = TA_TXRESPONSE_SENT_TORX ;    //wait for TX confirmation of sent response

        }

        else if(dw_event->type_pend == DWT_SIG_DW_IDLE) { //if timed out and back in receive then don't process as timeout

          inst_processrxtimeout(inst);

        }

        //else if RX_PENDING then wait for next RX event...

        message = 0; //clear the message as we have processed the event

      }

      break ;

      case DWT_SIG_TX_AA_DONE: //ignore this event - just process the rx frame that was received before the ACK response

      case 0:

      default :{

          if(message) { // == DWT_SIG_TX_DONE)

          inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT;

        }

        if(inst->done == INST_NOT_DONE_YET) inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT;

      }

      break;

      }

      break ; // end case TA_RX_WAIT_DATA

      default:

        //printf("\nERROR - invalid state %d - what is going on??\n", inst->testAppState) ;

        break;

  } // end switch on testAppState

  return inst->done;

} // end testapprun()

// -------------------------------------------------------------------------------------------------------------------

#if NUM_INST != 1

#error These functions assume one instance only

#else

// -------------------------------------------------------------------------------------------------------------------

// function to set the fixed reply delay time (in us)

//

// This sets delay for RX to TX - Delayed Send, and for TX to RX delayed receive (wait for response) functionality,

// and the frame wait timeout value to use.  This is a function of data rate, preamble length, and PRF

extern uint8_t dwnsSFDlen[];

void instancesetreplydelay(int delayus) { //delay in us

  int instance = 0;

  int margin = 3000; //2000 symbols

  int respframe = 0;

  int respframe_sy = 0;

  //configure the rx delay receive delay time, it is dependent on the message length

  float msgdatalen = 0;

  float preamblelen = 0;

  int sfdlen = 0;

  float x = 0;

  //Set the RX timeouts based on the longest expected message - the Final message

  //Poll = 13, Response = 20, Final = 44 bytes

  //msgdatalen = TAG_FINAL_MSG_LEN + FRAME_CRTL_AND_ADDRESS_S + FRAME_CRC;

  msgdatalen = ANCH_RESPONSE_MSG_LEN + FRAME_CRTL_AND_ADDRESS_S + FRAME_CRC;

  x = (float)ceil((double)(msgdatalen*8)/(double)330.0f);

  msgdatalen = msgdatalen*8 + x*48;

  //add some margin so we don't timeout too soon

  margin = 0; //(TAG_FINAL_MSG_LEN - TAG_POLL_MSG_LEN);

  x = (float) ceil((double)(margin*8)/(double)330.0f);

  margin = (int) (margin*8 + x*48);

  //assume PHR length is 172308ns for 110k and 21539ns for 850k/6.81M

  if(instance_data[instance].configData.dataRate == DWT_BR_110K) {

    msgdatalen *= 8205.13f;

    msgdatalen += 172308; // PHR length in nanoseconds

    margin *= 8205.13f;

  }

  else if(instance_data[instance].configData.dataRate == DWT_BR_850K) {

    msgdatalen *= 1025.64f;

    msgdatalen += 21539; // PHR length in nanoseconds

    margin *= 1025.64f;

  }

  else {

    msgdatalen *= 128.21f;

    msgdatalen += 21539; // PHR length in nanoseconds

    margin *= 128.21f;

  }

  //SFD length is 64 for 110k (always)

  //SFD length is 8 for 6.81M, and 16 for 850k, but can vary between 8 and 16 bytes

  sfdlen = dwnsSFDlen[instance_data[instance].configData.dataRate];

  switch (instance_data[instance].configData.txPreambLength) {

  case DWT_PLEN_4096 : preamblelen = 4096.0f; break;

  case DWT_PLEN_2048 : preamblelen = 2048.0f; break;

  case DWT_PLEN_1536 : preamblelen = 1536.0f; break;

  case DWT_PLEN_1024 : preamblelen = 1024.0f; break;

  case DWT_PLEN_512  : preamblelen = 512.0f; break;

  case DWT_PLEN_256  : preamblelen = 256.0f; break;

  case DWT_PLEN_128  : preamblelen = 128.0f; break;

  case DWT_PLEN_64   : preamblelen = 64.0f; break;

  }

  //preamble  = plen * (994 or 1018) depending on 16 or 64 PRF

  if(instance_data[instance].configData.prf == DWT_PRF_16M) {

    preamblelen = (sfdlen + preamblelen) * 0.99359f;

  }

  else {

    preamblelen = (sfdlen + preamblelen) * 1.01763f;

  }

  respframe_sy = (16 + (int)((double)((double)preamblelen + ((double)(msgdatalen + margin)/1000.0))/ 1.0256)) ;

  //this is the delay used for the delayed transmit (when sending the response, and final messages)

  instance_data[instance].pollTx2FinalTxDelay = convertmicrosectodevicetimeu (delayus);

  //the anchor to anchor ranging consist of A0 ranging to A1 and A2 and A1 ranging to A2

  //as there are less messages the ranging time is shorter (thus divide by 2)

  instance_data[instance].pollTx2FinalTxDelayAnc = convertmicrosectodevicetimeu (delayus/2 + 100);

  //this is the delay the anchors 1, 2, etc.. will send the response back at...

  //anchor 2 will have the delay set to 2 * fixedReplyDelayAnc

  //andhor 3 will have the delay set to 3 * fixedReplyDelayAnc and so on...

  //this delay depends on how quickly the tag can receive and process the message from previous anchor

  //(and also the frame length of course)

  respframe = (int)((double)preamblelen + ((double)msgdatalen/1000.0)); //length of response frame (micro seconds)

  if(instance_data[instance].configData.dataRate == DWT_BR_110K) {

    //set the frame wait timeout time - total time the frame takes in symbols

    instance_data[instance].fwtoTime_sy = respframe_sy + RX_RESPONSE1_TURNAROUND_110K + 400; //add some margin because of the resp to resp RX turn on time

    instance_data[instance].fwtoTimeAnc_sy = respframe_sy; //add some margin so we don't timeout too soon

    instance_data[instance].fixedReplyDelayAnc = convertmicrosectodevicetimeu (respframe + RX_RESPONSE1_TURNAROUND_110K);

    instance_data[instance].fixedReplyDelayAncP = (uint32_t) (((uint64_t) convertmicrosectodevicetimeu ((double)preamblelen)) >> 8) + 16;

    instance_data[instance].ancRespRxDelay = RX_RESPONSE1_TURNAROUND_110K ;

  }

  else {

    //set the frame wait timeout time - total time the frame takes in symbols

    instance_data[instance].fwtoTime_sy = respframe_sy + RX_RESPONSE1_TURNAROUND_6M81; //add some margin because of the resp to resp RX turn on time

    instance_data[instance].fwtoTimeAnc_sy =  respframe_sy;

    instance_data[instance].fixedReplyDelayAnc = convertmicrosectodevicetimeu (respframe + RX_RESPONSE1_TURNAROUND_6M81);

    instance_data[instance].fixedReplyDelayAncP = (uint32_t) (((uint64_t) convertmicrosectodevicetimeu ((double)preamblelen)) >> 8) + 16;

    instance_data[instance].ancRespRxDelay = RX_RESPONSE1_TURNAROUND_6M81 ;

  }

}

// -------------------------------------------------------------------------------------------------------------------

//

// Set Payload parameters for the instance

//

// -------------------------------------------------------------------------------------------------------------------

void instancesetaddresses(uint16_t address) {

  int instance = 0 ;

  instance_data[instance].instanceAddress16 = address ;       // copy configurations

}

#endif

/* ==========================================================

Notes:

Previously code handled multiple instances in a single console application

Now have changed it to do a single instance only. With minimal code changes...(i.e. kept [instance] index but it is always 0.

Windows application should call instance_init() once and then in the "main loop" call instance_run().

*/