Possibility to disabling native AFH function and using our own frequency hopping algorithm

[Panzerp]

Hi everyone,

I am developing a frequency hopping algorithm, including RSSI based channel evaluation and frequency hopping sequence generation. In my project, a nrf52840 device is used as master and 2 nrf52832 devices used as slaves.

The questions are as follows,

1. Is it possible to modify the channel map and update it in 1 second or less? If there's any constraint when updating channel map?

2. Is it possible to modify channel hopping sequence using nrf52 series with nordiac protocol stack?

I already know I can use  sd_ble_opt_get to get the current channel map and sd_ble_opt_set to set a new channel map,but I'm not sure if there's any  API or other methods I can use to make the devices communicate in the channel  sequence my algorithm generated.

Best regards, 

panzerp

[Sigurd]

Hi,

1. Is it possible to modify the channel map and update it in 1 second or less? If there's any constraint when updating channel map?

That should be possible. The Central decide the channel map.

2. Is it possible to modify channel hopping sequence using nrf52 series with nordiac protocol stack?

No. The stack uses the Bluetooth SIG defined Channel Selection Algorithm (CSA #2) for the channel hop selection.

I am developing a frequency hopping algorithm, including RSSI based channel evaluation and frequency hopping sequence generation. In my project, a nrf52840 device is used as master and 2 nrf52832 devices used as slaves.

There is an unofficial example for this here: https://github.com/jimmywong2003/nrf52-central-channel-map-update-with-survey

[Panzerp]

Thanks a lot.

If I don't use th Bluetooth protocol stack ,just use the 2.4G communication module.

Is it possiple to get the RSSI index from different channels without protocol API? For exemple,directly get the RSSI from related registers.

[Sigurd]

Hi,

If you are using the SoftDevice, you can use e.g. the function sd_ble_gap_rssi_get().

If you are not using the SoftDevice, you can access the radio register directly to get the RSSI. See this link: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.nrf52832.ps.v1.1%2Fradio.html&cp=5_2_0_22_9&anchor=rssi