Creating my own RSSI reader for nRF52840 dongle

[ella482]

I am trying to develop a program that can read the RSSI from the nrf52840 dongles without using the RSSI in the BLE app.

I have looked through the example code that is given but I do not see coding examples like this.

Has anyone tried creating their own RSSI reader before? How should I proceed?

[niebert]

You can do that on register level rather easily with TASKS_RSSISTART, TASKS_RSSISTOP and RSSISAMPLE. Read the corresponding section of the product specification of the Nrf52840. In order to sample, the radio has to be configured for reception (notably the channel has to be configured).

You can see an example of how that works in the proprietary RF examples like ./components/proprietary_rf/esb

The product specification states that "For the sample to be valid, reception must have started", however, you can actually sample any time when the radio is configured for reception. Eg. sampling while no packet is received will give you some indication of the noise floor on the selected channel.

Also note that RSSI sampling might require temperature based corrections for precision, but that depends on what you want to achieve.

[ella482]

Thank you! When I look for the product specification for the NRF52840, an error page occurs on the Nordic page.

 https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.nrf52%2Fdita%2Fnrf52%2Fchips%2Fnrf52840_ps.html

Should I install the nRF-Command-Line-Tools and write my test in python on an IDE?

I found a similar example here: https://devzone.nordicsemi.com/f/nordic-q-a/26284/scan-frequences-rssi

but it looks like they used java. Should I go ahead and try to mirror this in python and convert it to a hex file?

[ella482]

Could this rssi test also be implemented? https://github.com/NordicSemiconductor/pc-ble-driver-py/blob/master/tests/test_rssi.py

[Simonr]

Hi

You can find the nRF52840 product specification here. Both of the RSSI tests you've linked to should work with the nRF52 series boards.

Due to the summer holidays in Norway, our support team is understaffed this week, and delayed replies must be expected. Sorry for the inconvenience!

Best regards,

Simon