Hi,I’m a chinese,my english is not well.thank you for read my question.
Now i’m working on Double-sided two-way ranging mode .first,anchor send a message to tag,the tag can receive the message ,and also can get the receive timestamp,then it response to the anchor , the anchor actually received the message,but the result of the rx timestamp is 0! I checked the SYS_STATUS Register,other bits are ok except the LDEDONE,this bit is not set to 1,i used the officially firmware,but I can’t find the problem.oh my god,english is so difficult for me ,I hope you can understand
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anyone can help me 
Hi Roy ,
Could I ask you what hardware you have? Is it a EVK1000, TREK1000, or DWM1000, or your own design using a DW1000? If you’re using your own design, could you tell me the processor you’re using?
You state also that you’re using official firmware. Could I ask you what firmware? Is it certain example code you’re using? is it examples 5a/5b?
RX timestamp =0, means indeed that the LDE is not loaded. Would you give it enough time to load?
Depending on you MCU, the delays may need to be adjusted as they depend for example on the speed of the MCU.
Have a look at the ARM source code for the EVK1000, as the example states,
It may also be that you don’t give the nodes enough time to load the LDE or you may not have calibration values loaded.
Please see our IC user manual. 2.5.5 Default Receiver Configuration and especially the part where it talks about the LDE .
Regards,
Leo
Thank you very much! I am using the examples 5a/5b. Now I have found the problem,this is my problem ,“dwt_initialise(DWT_LOADUCODE)”，I changed DWT_LOADUCODE to DWT_LOADNONE ，so the LDE algorithm can’t work. Now ,I met a another question,the 05b resp examble can’t receive the second send from the 05a init , SYS_STATUS Register(0x8200f2) indicat that receive timeout.
I try to change the RESP_TX_TO_FINAL_RX_DLY_UUS,FINAL_RX_TIMEOUT_UUS,PRE_TIMEOUT ,but did not work
this is zhe resp ack response set this init timeout set
The mcu I use is stm32f103c8t6
I put the sys_ctrl_id check in here,and i find that the RXDLYE and RXENAB bit never set to 1.but I don’t confirm it has contact.
resp EXAMPLE I have seted,but it did’t work ,SYS_STATUS_ID indicate that the preamble detection timeout.
Now it’s work ok ,but the distance is very big,and I am keep on find the mistake
Hi again,
What distance do you get? It sounds like your antenna delays are not correct.
The delays are hard coded in the example code, see the notes on the bottom of the 5a/5b example main program.
To get a rough idea about what delays shall be applied, put the nodes on a known distance ( eg 10m) and adjust antenna delay until the average measured range matches the know distance as closely as possible.
For further information see again the DW1000 user manual section 8.3 IC Calibration – Antenna Delay,
Leo
Hi，Now the distance is ok ,distance error less than 10CM,the mistake is due to I have add some test program between tx and rx.the official firmware has no problem ,only need to modify the delay time.Now I want to make a test with using TDOA，but I don’t know how the DWM1000 to deal with multi tags,is there any suggest to it .Thank you! 
Hi,Leo
in official firmwrae 05b resp I set POLL_RX_TO_RESP_TX_DLY_UUS 10000, is that mean delay 10ms,if so ,I feel it’s too large,but if I set this value less than 10000,the tx always error, I hope this value as small as possible .what can I do.Thanks!