Specify exact BLE advert packet bits in SW

[ytesfai]

Hi,

I have been trying to use the radio_test example application to try and accomplish my goal but no success so far. My goal is to be able to compose an advertisement packet (Preamble + Access Code + PDU + CRC) pre-whitened and have it transmitted by the radio over the air exactly as is. i.e. no pre-pending of preamble + access address, appending a CRC nor whitening? Is this possible with the nrf52832 chip? If so, what is the best example application I can start with to help me accomplish this? If not, how close can I get to this. The most important thing for me is that the radio does not append CRC and does not perform whitening - i.e. SW will take care of both.

Thanks in advance for your help
Yohannes

[ytesfai]

 Emil Lenngren, hmolesworth  thanks so much for the quick responses. I get now how to disable CRC as well as disable whitening in the radio and do both those in SW. So the composed packet I have now is:

[PREAMBLE (0xAA), Whitened Adv Access Address (Whitened 0x8E89BED6), Whitened PDU, Whitened CRC]

Then configure radio:

- RADIO_CRCCNF_LEN_Disabled (disable CRC)

- Set whiteen in nrf_radio_packet_conf_t to false (disable whitening)

I will try this and report back, but in the meantime any guidance you can provide from your experience would be great.

Thanks
Yohannes

[ytesfai]

Hi again, 

I'm still stuck on this issue. I've tried various permutations of actual Base and Prefix registers to specify the access address, as well as header+PDU+CRC including inserting CRC from my code vs having the radio chip compute and insert the CRC block. I've also tried both pre-whitening the PDU+CRC in my application vs having the radio do the whitening and I still cannot receive the packet transmitted to be received by a BT sniffer. I suspect that I have:

- Bit ordering error
- Endianness issue
- Configuration issue
- Something else?

I received an email on 2/7 with the message that an Engineer has been assigned to look into this. Is this still the case? Any updates?

Thanks
Yohannes

[Emil Lenngren]

You wrote "Whitened Adv Access Address (Whitened 0x8E89BED6)", but the access address is not part of the data that is whitened. Only the PDU+CRC is whitened. The whitening is performed after the CRC has been both calculated and appended to the PDU.

[ytesfai]

Hi Emil Lenngren , yes I agree - unfortunately I didn't include all the combinations I tried but I tried both with whitened access address (more in desperation) and with just PDU+CRC whitened. I also tried no pre-whitening and had the radio perform whitening.