CoreHW ANT3 2x2 Antenna Array

Hi, we have project AoA direction finding. Firstly we have nrf5340 dk kits. Also CoreHW ANT3 2x2 matrix antenna kit. I run the direction finding connectionless demo on nrf5340-dk. I did some changes on code. 

static const uint8_t ant_patterns[] = {0x0, 0x4, 0xA, 0xE}; -> this new array of the antenna matrix.
dfe-antenna-num = <4>; -> number of antenna.
and lastly I added this code into the cte_recv_cv function.
    for (int i = 0; i < report->sample_count; i++) {
            if (report->sample_type == BT_DF_IQ_SAMPLE_8_BITS_INT) {
                printf("IQ sample %d: I = %d, Q = %d, channel index = %d\n", i, report->sample[i].i, report->sample[i].q, my->ant_ids);
            }
    }
My serial output like this...
Q1: Am i configured right? Anything else for my antenna array.
Q2: I'm not sure this is normal  IQ datas. So I want know which pins active while scanning. For example 
CTE[0]: samples count 45, cte type AOA, slot durations: 2 [us], packet status CRC OK, RSSI -630, "first switch pin active".
I found some pins description in "radio_df.c" file but i couldnt access the pins. Do you help me how can i overcome this problem.
Q3: While i trying something on visual devicetree editor the screen shown below opened. But this were not on purpose so how can i access again this menu.
 
And my setup below 
Parents
  • Hi

    As per the Direction Finding connectionless locator sample, the CTE length is 120µs and the switching slot is 1µs? Which will result in the following number of IQ samples (by default):

    • Eight samples from the reference period.

    • Switch-sample period duration is 120 µs - 12 µs = 108 µs. For the 1 µs antenna switching slot, the sample is taken every 2 µs (1 µs antenna switch slot, 1 µs sample slot). In this case, the number of samples from the switch-sample period is 108 µs / 2 µs = 54.

    What do you mean by "we couldn't find radio section we want to observe the raw data of IQ" exactly?

    Best regards,

    Simon

Reply
  • Hi

    As per the Direction Finding connectionless locator sample, the CTE length is 120µs and the switching slot is 1µs? Which will result in the following number of IQ samples (by default):

    • Eight samples from the reference period.

    • Switch-sample period duration is 120 µs - 12 µs = 108 µs. For the 1 µs antenna switching slot, the sample is taken every 2 µs (1 µs antenna switch slot, 1 µs sample slot). In this case, the number of samples from the switch-sample period is 108 µs / 2 µs = 54.

    What do you mean by "we couldn't find radio section we want to observe the raw data of IQ" exactly?

    Best regards,

    Simon

Children
  • Hi Simonr, thank you for answer. I know this topic asking numerios time on devzone. But i just want to clearify the situtation. In my case I'm using 2µs slot. Regarding white paper in my case CTE length 160µs. Guard period and reference period totally 12µs. So 160µs-12µs = 148µs. After that i assuming that first antenna used in reference period so i'm starting the second antenna. Also 148µs/4=37 samples collected. I explain my assuming on image. Could you verify my assuming?




    Mentioned white paper: docs.nordicsemi.com/.../intro.html

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