【DWM1000】 code 解密6一TAG 状态机第一步

 

我们前面分析过，不论ANCHOR 还是TAG，前面变量的初始化基本都是一样的，只是状态机必须明确区分不同的设备类型。我们从开始看TAG。由于初始化TAG的 testAppState一样初始化为TA_INIT。

    INST_STATES testAppState ;             int instance_init_s(int mode) TA_INIT

     case TA_INIT :

            // printf("TA_INIT") ;

            switch (inst->mode)

            {

                case TAG:

                {

                         int mode = 0;

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

                    inst->frameFilteringEnabled = 1 ;

                    dwt_setpanid(inst->panid);

                    dwt_seteui(inst->eui64);

#if (USING_64BIT_ADDR==0)

                                         //the short address is assigned by the anchor

#else

                    //set source address into the message structure

                    memcpy(&inst->msg.sourceAddr[0], inst->eui64, ADDR_BYTE_SIZE_L);

#endif

                    //change to next state - send a Poll message to 1st anchor in the list

                    inst->mode = TAG_TDOA ;

                    inst->testAppState = TA_TXBLINK_WAIT_SEND;

                                         memcpy(inst->blinkmsg.tagID, inst->eui64, ADDR_BYTE_SIZE_L);

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

                                               if((dwt_getldotune() != 0)) //if we need to use LDO tune value from OTP kick it after sleep

                                               {

                                                        mode |= DWT_LOADLDO;

                                               }

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

                                               {

                                                        mode |= DWT_LOADOPSET;

                                               }

#if (DEEP_SLEEP == 1)

                    if (inst->sleep_en)

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

#endif

                }

                break;

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

    inst->frameFilteringEnabled = 1 ;

控制滤波器，只接受DATA 和ACK数据，并且将frameFilteringEnabled 设置为1. 主要这个不TAG的frameFilteringEnabled，与前面的ANCHOR的frameFilteringEnabled 是一个东西，但是赋值分为两个，因为是两份代码分别跑在两个模块中。

    dwt_setpanid(inst->panid);

                    dwt_seteui(inst->eui64);

Panid 和 64位地址设定，与ANCHOR一样。

#if (USING_64BIT_ADDR==0)

                                         //the short address is assigned by the anchor

#else

                    //set source address into the message structure

                    memcpy(&inst->msg.sourceAddr[0], inst->eui64, ADDR_BYTE_SIZE_L);

#endif

由于短地址还没有，所以msg.sourceAddr目前只能是64位长地址。

    inst->mode = TAG_TDOA ;

这个mode之前没有用过，我们先记录下，以后肯定会用到TAG_TDOA

inst->testAppState = TA_TXBLINK_WAIT_SEND;

这个testAppState记录上，下次进去testapprun_s 找作案现场用

  memcpy(inst->blinkmsg.tagID, inst->eui64, ADDR_BYTE_SIZE_L);

又一个变量被设置，我们先记录，后面用的时候查看， 这里保存了TAG的长地址

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

                                               if((dwt_getldotune() != 0)) //if we need to use LDO tune value from OTP kick it after sleep

                                               {

                                                        mode |= DWT_LOADLDO;

                                               }

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

                                               {

                                                        mode |= DWT_LOADOPSET;

                                               }

mode是个变量，给这个mode 赋了很多值

#if (DEEP_SLEEP == 1)

                    if (inst->sleep_en)

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

#endif

                }

                break;

如果我们没有使用sleep，前面mode都感觉没有用了，mode主要作用是告诉chip醒来以后需要恢复那些量，我们先不具体分析了。现在break了，和ANCHOR一样，返回值为0，符合while条件会再次跳入到testapprun_s。

我们根据上面的testAppState = TA_TXBLINK_WAIT_SEND;再次找作案现场

        case TA_TXBLINK_WAIT_SEND :

            {

                                     int flength = (BLINK_FRAME_CRTL_AND_ADDRESS + FRAME_CRC);

                //blink frames with IEEE EUI-64 tag ID

                inst->blinkmsg.frameCtrl = 0xC5 ;

                inst->blinkmsg.seqNum = inst->frame_sn++;

                                     dwt_writetxdata(flength, (uint8 *)  (&inst->blinkmsg), 0) ; // write the frame data

                                     dwt_writetxfctrl(flength, 0);

                                     //using wait for response to do delayed receive

                                     inst->wait4ack = DWT_RESPONSE_EXPECTED;

                                     dwt_setrxtimeout((uint16)inst->fwtoTimeB_sy);  //units are symbols

                                     //set the delayed rx on time (the ranging init will be sent after this delay)

                                     dwt_setrxaftertxdelay((uint32)inst->rnginitW4Rdelay_sy);  //units are 1.0256us - wait for wait4respTIM before RX on (delay RX)

                                     dwt_starttx(DWT_START_TX_IMMEDIATE | inst->wait4ack); //always using immediate TX and enable dealyed RX

                                     inst->instToSleep = 1; //go to Sleep after this blink

                inst->testAppState = TA_TX_WAIT_CONF ; // wait confirmation

                inst->previousState = TA_TXBLINK_WAIT_SEND ;

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

            }

            break ; // end case TA_TXBLINK_WAIT_SEND

其中如下几步是DWM1000 代码中发送数据的基本流程

dwt_writetxdata(flength, (uint8 *)  (&inst->blinkmsg), 0) ;

dwt_writetxfctrl(flength, 0);

dwt_setrxtimeout((uint16)inst->fwtoTimeB_sy);  //units are symbols

dwt_setrxaftertxdelay((uint32)inst->rnginitW4Rdelay_sy);

dwt_starttx(DWT_START_TX_IMMEDIATE | inst->wait4ack);

发送了一个数据包，数据包的内容为

inst->blinkmsg.frameCtrl = 0xC5 ;

inst->blinkmsg.seqNum = inst->frame_sn++;

其中还求必须有回应

//using wait for response to do delayed receive

inst->wait4ack = DWT_RESPONSE_EXPECTED;

发送完延时打开接收器（设定rx接收timeout以及打开接收器的时间）

dwt_setrxtimeout((uint16)inst->fwtoTimeB_sy);  //units are symbols

dwt_setrxaftertxdelay((uint32)inst->rnginitW4Rdelay_sy);

设定了一些变量，有些还是很重要的。

inst->instToSleep = 1; //go to Sleep after this blink

inst->testAppState = TA_TX_WAIT_CONF ; // wait confirmation

inst->previousState = TA_TXBLINK_WAIT_SEND ;

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

同样根据inst->testAppState = TA_TX_WAIT_CONF ; 找下次进去testapprun_s 的作案现场。

到现在为止，我们分析代码发现，ANCHOR在等TAG发数据，现在TAG给它发送了，ANCHOR应该会收到数据了，而TAG依然会接着执行。 我们先看TAG，然后在看ANCHOR。 记住目前的状态是ANCHOR准备接收数据了。

接着看TAG，退出testapprun_s时，done为INST_DONE_WAIT_FOR_NEXT_EVENT;

    if(done == INST_DONE_WAIT_FOR_NEXT_EVENT_TO) //we are in RX and need to timeout (Tag needs to send another poll if no Rx frame)

    {

        if(instance_data[instance].mode == TAG_TDOA)

        {

                  instance_data[instance].instancetimer += instance_data[instance].tagBlinkSleepTime_ms; //set timeout time

            instance_data[instance].instancetimer_en = 1; //start timer

        }

        instance_data[instance].stoptimer = 0 ; //clear the flag - timer can run if instancetimer_en set (set above)

        instance_data[instance].done = INST_NOT_DONE_YET;

看后面的注释，目前TAG发送一笔Blink信号后，确实有个延时打开接收器的动作，所以说确实现在是RX状态。

if(done == INST_DONE_WAIT_FOR_NEXT_EVENT_TO) //we are in RX and need to timeout

我们再看看INST_DONE_WAIT_FOR_NEXT_EVENT_TO 这个宏定义，可以看出需要等待一个timeout，就知道if判断里面是开启定时器，等待一段时间了

#define INST_DONE_WAIT_FOR_NEXT_EVENT_TO    2   //this signifies that the current event has been processed and that instance is waiting for next one with a timeout

//which will trigger if no event coming in specified time

我们再来分析定时器代码，因为我们前面分析，TAG现在的mode是TAG_TDOA，所以摘录出其对应的代码

        if(instance_data[instance].mode == TAG_TDOA)

        {

            instance_data[instance].instancetimer += instance_data[instance].tagBlinkSleepTime_ms; //set timeout time

            instance_data[instance].instancetimer_en = 1; //start timer

        }

        instance_data[instance].stoptimer = 0 ;

 //clear the flag - timer can run if instancetimer_en set (set above)

        instance_data[instance].done = INST_NOT_DONE_YET;

我们标注颜色的两个变量，我们搜索一下之前是否有初始化

uint32       instancetimer;                  

// e.g. this timer is used to timeout Tag when in deep sleep so it can send the next poll message

int tagBlinkSleepTime_ms; instancesettagsleepdelay  1000

我们没有看到instancetimer的初始化，我们暂时考虑它为0，但是tagBlinkSleepTime_ms 是1000，所以通过第一句赋值语句instancetimer 等于1000了。

其它几个变量instancetimer_en和stoptimer 立马会用到，注意一下done此时被赋值为INST_NOT_DONE_YET，这里也记录一下，后面看怎么走了。

接着看代码

if((instance_data[instance].instancetimer_en == 1) && (instance_data[instance].stoptimer == 0))

这个if里面两个变量判定与刚才完全一样，所以立马用到了它们，而且满足条件，接着看if里面的内容

  if(instance_data[instance].instancetimer < portGetTickCount())

  {

                event_data_t dw_event;

        instance_data[instance].instancetimer_en = 0;

                dw_event.rxLength = 0;

                dw_event.type = DWT_SIG_RX_TIMEOUT;

                dw_event.type2 = 0x80 | DWT_SIG_RX_TIMEOUT;

                //printf("PC timeout DWT_SIG_RX_TIMEOUT ");

                instance_putevent(dw_event);

  }

If条件里变量instancetimer 是我们刚刚计算赋值的，而portGetTickCount()函数我们之前没有遇到过，简单看下

#define portGetTickCount()                      portGetTickCnt()

unsigned long portGetTickCnt(void)

{

         return time32_incr;

}

我们看到这里，它返回一个time32_incr. 看到这里绝对这个变量没有初始化，假定是0，那就错误了。 这里肯定是有个定时器了，time32_incr是一个全局变量，在timer中断里增加。 所以portGetTickCnt() 返回一个实时时间量，再看我们之前的instancetimer认为是

instance_data[instance].instancetimer += instance_data[instance].tagBlinkSleepTime_ms; 现在感觉instance_data[instance].instancetimer应该也是一个在定时器累加的全部量，不然两者没有可比性，没法有相对延时的概念。

简单看下time32_incr 一些像代码。

void SysTick_Handler(void)

{

         time32_incr++;

#ifdef FILESYSTEM_ENABLE

         fsd_service();

#endif

}

通过下面的语句判断定时时间是否到了

if(instance_data[instance].instancetimer < portGetTickCount())

里面的语句，就是产生一个事件，事件type为DWT_SIG_RX_TIMEOUT，通过instance_putevent(dw_event)加入到事件列表，我们之前是通过peek查看是否有事件。

这几个event 相关的函数暂时不会影响我们分析大局，先暂时不看它们了。

instancetimer_en 设置为0，标志着停止计时。

instance_data[instance].instancetimer_en = 0

虽然我们把TAG代码中的instance_run中的代码全部分析完了，但是其实TAG实际跑代码不是这样的。正确的顺序应该是，接着我们刚才设定定时器à 查看定时器是否到期(没有到期)à返回Main 函数(我们分析过ANCHOR，除了打印信息，没有实质内容)à重新 instance_runà……定时器到期，设定event事件。

其中……可能重复了很多次，我们需要再看看里面怎么执行的，是否还会增加定时器等等，我们逐一再看看，这段时间是TAG发送完blink后打开接收器等待ANCHOR应答的时间段，虽然实际上时间可能1s不到，但是我们分析代码可能需要几个小时甚至更长。 接着看第二次进入instance_run。

int done = INST_NOT_DONE_YET;

int message = instance_peekevent(); //get any of the received events from ISR

while(done == INST_NOT_DONE_YET)

{

         //int state = instance_data[instance].testAppState;

            done = instance_localdata[instance].testapprun_fn(&instance_data[instance], message) ;                                               // run the communications application

         //we've processed message

         message = 0;

}

注意和这里，因为我们假定是时间没有到，所以peekevent应该还是啥也没有，所以message返回的还是0. 所以我们会再次进入testapprun_s。 我们需要找上次testAppState，

inst->testAppState = TA_TX_WAIT_CONF ; // wait confirmation

inst->previousState = TA_TXBLINK_WAIT_SEND ;

东西记不住1是返回去看代码，而是用笔记录，我们之前分析有记录。直接在testapprun_s 找相应的case

case TA_TX_WAIT_CONF :  //after tx,waif for comfirm

这里代码不少，我们需要根据if删减一下，这里事件TA_TX_WAIT_CONF，其实就是等待是否有应答，因为TAG 在发送blink信号的时候明确提出需要应答

 {

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 == 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) ", 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;

         }

  inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT;

  break;

}

  inst->done = INST_NOT_DONE_YET;

                if(inst->previousState == TA_TXFINAL_WAIT_SEND)// 不满足

                {

                 ……

                }

                else if (inst->gotTO) //timeout

                {

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

                    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) // 不满足

                                               {

                                   ……

                                               }

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

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

                                               message = 0;

                }

            }

我们先一部分一部分的分析

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

  {

         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) ", 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;

         }

  inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT;

  break;

}

DWT_SIG_TX_DONE 这个事件应该是发送一帧数据后，DWM1000 中断里产生的，我们刚才在TAG发送了一帧数据，所以如果DWM1000 处理完了，应该会put event，事件type是DWT_SIG_TX_DONE。 好，那我们假设，下发数据后，DWM1000 还没有发送出去，我们代码已经执行到这里了，确实满足这个判断。 继续执行里面的

if(dw_event->type == DWT_SIG_RX_TIMEOUT)

DWT_SIG_RX_TIMEOUT， 这个事件我们之前见过，是定时器溢出触发的的，我们刚才假定DWM1000 很快执行到这里，所以没有溢出，不满足条件。直接执行了。

  inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT;

  break;

和TAG 上次退出时一样。一样分别是有如下几个关键变量没有修改

inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT;

inst->testAppState = TA_TX_WAIT_CONF ; // wait confirmation

inst->previousState = TA_TXBLINK_WAIT_SEND ;

因为这个时候定时器已经开启了，我们看看TAG此时退出到run里会执行那些。

    if(done == INST_DONE_WAIT_FOR_NEXT_EVENT_TO) //we are in RX and need to timeout (Tag needs to send another poll if no Rx frame)

    {

        if(instance_data[instance].mode == TAG) //Tag (is either in RX or sleeping)

        {

           ……

        }

        if(instance_data[instance].mode == TAG_TDOA)

        {

            instance_data[instance].instancetimer += instance_data[instance].tagBlinkSleepTime_ms; //set timeout time

            instance_data[instance].instancetimer_en = 1; //start timer

        }

        instance_data[instance].stoptimer = 0 ; //clear the flag - timer can run if instancetimer_en set (set above)

        instance_data[instance].done = INST_NOT_DONE_YET;

    }

再次给instancetimer它赋值，我们之前所instancetimer 是个动态量，分析有误。。。。。

###############》 其实定时时长没有变，所以还是和原来等待时间一样，后面持续在看是否溢出。==è重新分析instancetimer。

好，这是一种假设，另一种假设，依然针对下面这几行代码。

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

  {

         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) ", 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;

         }

  inst->done = INST_DONE_WAIT_FOR_NEXT_EVENT;

  break;

}

我们分析代码可以知道，当没有发送完一直在等待事件DWT_SIG_TX_DONE，加入一种情况，DWM1000 坏掉了或者中断配置有问题，这个事件一直等不到，那么，上面的循环一直执行到定时器溢出。会满足后面的if(dw_event->type == DWT_SIG_RX_TIMEOUT)，判断里面讲inst->gotTO = 1。 这个分支代码也很长了，因为我们可能需要在instance_run获取些信息了。 暂时不考虑怎么极端的情况。先预留一个DWM1000配置有误或者损坏TX后执行情况代码分析。

好了，我们假定DWM1000 一切正常，所以过了一段时间，收到了DWT_SIG_TX_DONE，那就不满足如下if条件，直接往后看吧。

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

inst->done = INST_NOT_DONE_YET;

if(inst->previousState == TA_TXFINAL_WAIT_SEND)

                {

                ……

                }

                else if (inst->gotTO) //timeout

                {

                                               ……

                }

                else

                {

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

                                               if(inst->previousState == TA_TXPOLL_WAIT_SEND)

                                               {

                     ……

                    }

                    inst->testAppState = TA_RXE_WAIT ;            

         // After sending, tag expects response/report, anchor waits to receive a final/new poll

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

                                               message = 0;

                }

            }

            //break ; // end case TA_TX_WAIT_CONF

把不满足条件的代码注释掉，发现实际上当TAG发送完blink后这里只是简单的给几个重要的变量赋值，好好记录一下，根据经验这个很重要

inst->done = INST_NOT_DONE_YET;

inst->testAppState = TA_RXE_WAIT ;

一个全局变量txu.txTimeStamp赋值，这个初始化的时候没有动过，所以是0. 其中dw_event->timestamp 这个应该是DWM1000 在发送数据的时候MARK的时间，因为需要知道接收发送数据的时间换算距离。 其实发送blink 的时间应该没有什么意义，我们暂时不考虑，用到在回来看。

后面有个比较诡异的地方，没有break，直接会执行后面的case

   //break ; // end case TA_TX_WAIT_CONF

后面的case是TA_RXE_WAIT，我们在ANCHOR分析过，它是打开接收器，在TA_RXE_WAIT后面重要变量被修改了

  inst->testAppState = TA_RX_WAIT_DATA;

我们根据上面代码分析经验，我们简要瞅一眼TA_RX_WAIT_DATA。

  case TA_RX_WAIT_DATA :   //already recive a message                   // Wait RX data

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

switch (message)

            {

在TA_RX_WAIT_DATA 会根据message执行不同的代码，我们前面分析了，如果没有event或者一些没有message 的event产生时，TA_RX_WAIT_DATA其实啥都不执行。也就是只有就收到无线信号时，message里面才是一个真实的数据。

分析到这里，TAG也在等ANCHOR的数据了。

我们回顾一下，ANCHOR启动后直接开始接收器等到TAG发送数据，分析TAG，TAG先发送一笔blink给ANCHOR，AHCHOR怎么回复blink我们还没有分析，TAG此时正在等ANCHOR的回复了，卡在这里了，我们下一节的内容主要分析ANCHOR接收blink以及回复blink。

遗留问题:TAG开了一个定时器，最后是取消了还是溢出了？