fail err(-11) when in DF,I i can get the iq samples,but i use them to caculate the angle of Tx,how to solve it?

I use both nrf52833 boards to do AOA  test.But i use thr antenna array board of silab.The board are 16 antennas.I use the NCS version 1.9.1.

The next is my device stcture.

1

I conple the precedure and the flash the precedure to my board.i can get the  IQ samples.But i think it may be damege to my algorithm of angle.

But i can;t solve the this problem.can you help me?

Parents
  • Hi

    Our Bluetooth: Direction finding central is designed for the Nordic Semiconductor design 12 patch antenna matrix.
    You can use this with any other antenna. However, the algorithm will be different for different antennas.

    I suggest that you ask the designers of your antenna about the algorithm for that antenna.

    Regards,
    Sigurd Hellesvik

  • ok,thanks.besides,I want to ask how to solve the err(-11) problem.I am sorry that my output code have't been saved.

    Now i link the line with my device.I find that my err(-11) have disappeared.I want yo know what the err(-11) is linked to?

    is there a device  problem?

    if you know,please tell me.Thanks for your advice.

    besides this,i want toi know more information about your antenna array of 12.

    because i want to get the calculation of the angle.As yiuy mentioned,the designe of antenna array is related to the algorithm.

    I am looking forward to your answer.Thanks!

  • The ISP1907-AOA-DK is based on our design, so you could have a look at their project.
    If you need our design files, contact your regional sales manager.

    swz_nordic5340 said:
    how to solve the err(-11) problem

    Which function returns the -11 error?

    For some more information on the nRF Connect SDK samples for direction finding and their algorithms, see this answer by Simon.

    Regards,
    Sigurd Hellesvik

  • sorry,now i can't get this err code.

    i think it is in CTE  parser. I think that this err code is  my device problem.

    "The ISP1907-AOA-DK is based on our design, so you could have a look at their project.
    If you need our design files, contact your regional sales manager"

    as you menthion,i get the same files of amtenna array.The most files are the circuit diagram of aantenna array.

    what is the more ,i want to get the more information of how to gert the angle of algorithm.

  • From this answer by Simon:
    "Please note that the output you see from these samples won't be the "finished" angle of arrival, as this just transmits the raw IQ data to your central device. It is up to you to add an AoA algorithm that handles these values and converts them into readable data. Nordic will not provide the direction finding algorithm, and customers/users are expected to get that elsewhere. In order to use the IQ data you get from the beacon you will need an AOA algorithm, which we don't provide. There is no point in looking at the raw data as it needs to be converted into vector form to review it properly. You can check out this page for information on the various formulas used to translate IQ data between polar and rectangular form. "

    Regards,
    Sigurd Hellesvik

Reply
  • From this answer by Simon:
    "Please note that the output you see from these samples won't be the "finished" angle of arrival, as this just transmits the raw IQ data to your central device. It is up to you to add an AoA algorithm that handles these values and converts them into readable data. Nordic will not provide the direction finding algorithm, and customers/users are expected to get that elsewhere. In order to use the IQ data you get from the beacon you will need an AOA algorithm, which we don't provide. There is no point in looking at the raw data as it needs to be converted into vector form to review it properly. You can check out this page for information on the various formulas used to translate IQ data between polar and rectangular form. "

    Regards,
    Sigurd Hellesvik

Children
  • ok,thanks.i know whether other antenna array with thiis nordic board make some influence in IQ values.

    as i said some days ago,i find that the IQ sample  are so small.

    I get the IQ sample from silab as next.

    {
    	"channel":	18,
    	"rssi":	-55,
    	"sequence":	173,
    	"samples":	[1, -57, -56, -2, -3, 57, 56, 2, 3, -56, -56, -3, -3, 57, 55, 6, 36, 45, -32, -87, -21, -13, -13, -41, 58, -68, -84, 29, 81, -29, -22, 2, -84, -88, 54, 95, -9, -68, -6, 20, -111, 34, 85, -24, -20, -37, 54, 2, 21, 52, -16, -92, -18, -15, -7, -42, 68, -57, -87, 15, 84, -15, -22, -1, -64, -108, 40, 104, 1, -69, -10, 19, -114, 21, 88, -9, -13, -40, 53, 10, 12, 56, 0, -94, -16, -17, 1, -43, 78, -44, -88, -1, 86, 1, -22, -4, -45, -115, 21, 111, 14, -67, -13, 17, -118, 0, 88, 2, -5, -42, 51, 19, 0, 58, 14, -93, -12, -20, 7, -42, 83, -31, -86, -13, 85, 13, -20, -9, -25, -125, 0, 116, 26, -64, -15, 15, -119, -18, 86, 22, 0, -42, 46, 27, -8, 57, 31, -87, -8, -23, 13, -40, 88, -14, -84, -29, 82, 28, -19, -12, -1, -126, -18, 109]

    The nrf52833 board with antenna array of silab as next  as IQ values.

    CTE[DE:86:9B:6D:43:F0 (random)]: samples count 45, cte type AOA, slot durations: 2 [us], packet status CRC OK, RSSI -580
    
    IQ sample content :
    
    sample[0] = I:-2 Q:13
    
    sample[1] = I:0 Q:-14
    
    sample[2] = I:-2 Q:13
    
    sample[3] = I:1 Q:-14
    
    sample[4] = I:-3 Q:12
    
    sample[5] = I:2 Q:-14
    
    sample[6] = I:-3 Q:13
    
    sample[7] = I:2 Q:-14
    
    sample[8] = I:10 Q:-8
    
    sample[9] = I:-12 Q:-2
    
    sample[10] = I:-9 Q:-10
    
    sample[11] = I:0 Q:-3
    
    sample[12] = I:3 Q:-10
    
    sample[13] = I:-4 Q:5
    
    sample[14] = I:4 Q:7
    
    sample[15] = I:-5 Q:3
    
    sample[16] = I:-6 Q:3
    
    sample[17] = I:-28 Q:5
    
    sample[18] = I:2 Q:-4
    
    sample[19] = I:11 Q:3
    
    sample[20] = I:-2 Q:-13
    
    sample[21] = I:4 Q:-13
    
    sample[22] = I:1 Q:-1
    
    sample[23] = I:10 Q:-2
    
    sample[24] = I:-7 Q:-2
    
    sample[25] = I:-4 Q:7
    
    sample[26] = I:-6 Q:-3
    
    sample[27] = I:-6 Q:-4
    
    sample[28] = I:-18 Q:-24
    
    sample[29] = I:4 Q:-1
    
    sample[30] = I:1 Q:11
    
    sample[31] = I:8 Q:-9
    
    sample[32] = I:12 Q:-4
    
    sample[33] = I:1 Q:1
    
    sample[34] = I:6 Q:7
    
    sample[35] = I:-2 Q:-7
    
    sample[36] = I:-9 Q:0
    
    sample[37] = I:0 Q:-7
    
    sample[38] = I:-1 Q:-7
    
    sample[39] = I:11 Q:-27
    
    sample[40] = I:2 Q:2
    
    sample[41] = I:-10 Q:7
    
    sample[42] = I:12 Q:1
    
    sample[43] = I:9 Q:9
    
    sample[44] = I:-1 Q:1
    as the err(-11) problem,when i meet ,i will call back to you.

    Thanks.

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