IQ sampling in BLE payload

RE: IQ sampling in BLE payload

rishab jay — Wed, 28 Jan 2026 10:49:29 GMT

Thanks for the detailed explanation — this really helps clarify how IQ sampling works in BLE payloads!
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RE: IQ sampling in BLE payload

mariamartin — Tue, 15 Jul 2025 10:18:15 GMT

I encountered a similar issue while working with the nRF52833. It appears that certain register settings can be challenging to modify programmatically, particularly when working with the RADIO peripheral. Interestingly, I found that sometimes manual changes during debugging can yield better results, which reminded me of the importance of testing and verifying configurations, much like how I approached my own experiences with an iq test free to gauge performance. Have you tried resetting the device or ensuring that no other configurations are interfering with your settings?

RE: IQ sampling in BLE payload

brook — Fri, 27 Oct 2023 07:56:13 GMT

thanks. very much.
I will give a message after I get result.

RE: IQ sampling in BLE payload

Jasperbrg — Thu, 26 Oct 2023 08:09:26 GMT

Yes, I got it to work with this DFECTRL1 and DFECTRL2 configuration:

uint32_t conf;
conf = ((((uint32_t)20 << RADIO_DFECTRL1_NUMBEROF8US_Pos) & RADIO_DFECTRL1_NUMBEROF8US_Msk) |
    ((uint32_t)RADIO_DFECTRL1_DFEINEXTENSION_Payload << RADIO_DFECTRL1_DFEINEXTENSION_Pos) |
    ((uint32_t)RADIO_DFECTRL1_TSWITCHSPACING_4us << RADIO_DFECTRL1_TSWITCHSPACING_Pos) |
    ((uint32_t)RADIO_DFECTRL1_TSAMPLESPACINGREF_1us << RADIO_DFECTRL1_TSAMPLESPACINGREF_Pos) |
    ((uint32_t)RADIO_DFECTRL1_SAMPLETYPE_IQ << RADIO_DFECTRL1_SAMPLETYPE_Pos) |
    ((uint32_t)RADIO_DFECTRL1_TSAMPLESPACING_4us << RADIO_DFECTRL1_TSAMPLESPACING_Pos) |
    (((uint32_t)0 << RADIO_DFECTRL1_AGCBACKOFFGAIN_Pos) & RADIO_DFECTRL1_AGCBACKOFFGAIN_Msk));

NRF_RADIO->DFECTRL1 = conf;

conf = ((((int16_t)15 << RADIO_DFECTRL2_TSAMPLEOFFSET_Pos) & RADIO_DFECTRL2_TSAMPLEOFFSET_Msk) |
	    (((int16_t)2000 << RADIO_DFECTRL2_TSWITCHOFFSET_Pos) & RADIO_DFECTRL2_TSWITCHOFFSET_Msk));

NRF_RADIO->DFECTRL2 = conf;

RE: IQ sampling in BLE payload

brook — Thu, 26 Oct 2023 03:51:11 GMT

do you succeed in this task?

RE: IQ sampling in BLE payload

Jasperbrg — Fri, 03 Mar 2023 15:32:27 GMT

Edit: I see now that I had a logical mistake on my side. My bad. Thanks for your help!

RE: IQ sampling in BLE payload

Jasperbrg — Fri, 03 Mar 2023 15:10:00 GMT

Hi Simon, thanks for the fast reply.

My issue right now is just that I cannot modify the DFEINEXTENSION bit for some reason, except when I use the register editor of the debugger as shown in the picture. But when I try to clear the bit in the code, it has no effect. Could there be some kind of write protection on that bit?

RE: IQ sampling in BLE payload

Simonr — Fri, 03 Mar 2023 10:22:21 GMT

Setting the DFEINEXTENSION bit to 0 and doing I/Q sampling in the payload will not be supported by Bluetooth and is for proprietary modes only, which is why it isn't mentioned in our Direction Finding Whitepaper (which focuses on BLE). How to use it is described in the PS (the output from the radio will be the same as for normal CTE, you just need to determine what to trig from and how much delay from the trigger point to the first sample to be taken), but as it will only be used for proprietary solutions it's difficult to describe in the likes of a white paper.

Best regards,

Simon