measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Mon, 18 Sep 2023 16:00:33 GMT

Hi,

[quote user="Leonardo Balocchi"]1) how to save the RSSI values from the RSSI viewer desktop application (or if there is another way it may be ok, as long as the RSSI is always correct)[/quote]

It cannot save the RSSI values from the RSSI viewer app which doesn't provide this feature.

[quote user="Leonardo Balocchi"]Is there a way perhaps to insert terminal commands directly within the main.c function in VS Code?[/quote]

You could modify the sample and assign the value as you want.

Regards,
Amanda H.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Fri, 15 Sep 2023 10:28:01 GMT

Hi Amanda, unfortunately the examples you gave me were not very helpful, they don't explain how to extract RSSI values over time.

Concerning the second request, the problem is this, when I use the RSSI viewer on the nRF52840 DK, and the radio_test loaded on the BC840 then I read correctly the RSSI value from the RSSI viewer (the two boards are at a distance of 60 cm, so the path loss at 2.4 GHz is about 36 dB, then on the BC I mounted an antenna that has gain 5 dBi, and transmitting 0 dBm with the BC I see that the RSSI is about -34 dBm, as I expect).

Leaving the same setup, with the nrf_dm example, it prints me an absolutely incorrect RSSI value, we are around -2 dBm (perhaps because in the latter case I see the sum of several channels?).

So I cannot use the nrf_dm example to extract the RSSi values I need, but I should do it from the RSSI viewer, because from there I read the value I expect according to RSSI theory.

So my problems are:
1) how to save the RSSI values from the RSSI viewer desktop application (or if there is another way it may be ok, as long as the RSSI is always correct)
2) how to keep the instructions sent from the terminal saved in the BC840's memory, because otherwise when I disconnect and then reconnect it, what happens is that the transmission instructions are lost (so I think they are saved in volatile memory)

Is there a way perhaps to insert terminal commands directly within the main.c function in VS Code?

Thanks,

Leonardo

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Thu, 14 Sep 2023 15:20:13 GMT

Hi,

[quote user="Leonardo Balocchi"]Is there a way to set the single channel and save all the RSSI values that are read so that I can then plot them in a graph?[/quote]

There is no such example, but you can take a look at this post or the hci_pwr_ctrl sample to get RSSI values.

[quote user="Leonardo Balocchi"]To go back to the previous problem, that is, the RSSI value measurement with the "nrf_dm" application, where I was seeing inconsistent RSSI values.[/quote]

Could you elaborate more on what you mean by the "inconsistent RSSI values"?

-Amanda H.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Thu, 14 Sep 2023 09:25:58 GMT

Hi Amanda,

I was able to solve the problem and now I can send the carrier from one board and view it via RSSI viewer on the other (with the "radio_test" application).
I wanted to ask you another thing, now I would need to set up my experimental setup, as I told you, so that I select a single channel (out of the 40 available) and continuously send bit sequences interspersed between the two boards, so that the RSSI is measured.
Is there a way to set the single channel and save all the RSSI values that are read so that I can then plot them in a graph?

To go back to the previous problem, that is, the RSSI value measurement with the "nrf_dm" application, where I was seeing inconsistent RSSI values.

Thanks in advance,

Leonardo

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Fri, 08 Sep 2023 12:39:30 GMT

Hi,

[quote user="Leonardo Balocchi"]Are we sure that's the right way to programme the BC840E?[/quote]

From the doc, it seems like that. You also could use the J-Link debug probe to replace nRF52840DK for programming. Do you also try other BC840 E boards? If you also have programming issues with the J-Link debug probe, you should contact the provider since BC840 E is not produced by Nordic.

-Amanda H.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Fri, 08 Sep 2023 07:35:52 GMT

The baud rate is 115200 on the serial settings.

When I connect only the nRF52840 board to the PC and load the zephyr.hex programme (i.e. without the 10 connection wires to the BC840E) the serial terminal seems to work.

Instead it prints in the serial terminal continuously the same values I showed you above if I program the nRF52840 with the 10 connection wires attached and then the BC840E as well.

I tried changing USBs and Putty and the same thing happens.
Are we sure that's the right way to programme the BC840E? I'm pretty sure the problem lies in flashing the programme on nRF52840 when the other board (BC840 E) is also attached via 10 wires, because only in this case does the programme give problems.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Thu, 07 Sep 2023 15:35:18 GMT

[quote user="Leonardo Balocchi"]The boud rate is correct[/quote]

What the baud rate do you use?

Could you try to connect with Putty or use another USB cable?

-Amanda H.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Thu, 07 Sep 2023 14:03:56 GMT

OK, I solved the update issue, now the building of the "radio_test" application seems to work.

I remind you that I have 2 boards, the nRF52840 board and the BC840E evaluation board.
I loaded the radio test programme into the nRF52840 board connected via USB to the PC, and using the "flash" in VS Code.
To this first board the BC840E board is connected via a 10-wire connection (for the power supply the BC840E is not connected via USB to the pc, but to an external battery), and according to what you told me above, by flashing the programme to the nRF52840 connected via 10 wires to the BC840E, the same programme should also be loaded inside this second board.

Then through the serial terminal I give the commands you wrote me above ("start_channel" 40 and "start_tx_modulated_carrier"), always with both boards connected as I described, but opening the serial terminal I see these writings printed:
"bfdegeffcgfedd e!e "f#d$f%f&e'e(f)f*f+c,e-f.g/f0d1g2g3f4f5c6f7g8f9g:c;d<e=g>g?c@eAfBfCgDdEfFeGfHfIdJeKfLeMgNdOfPddffeedee d
f
f
ceffgadfgfddedbgfe e!b "e#f$f%f&e'f(f)e*g+d,g-e.f/g0c1f2f3g4f5e6g7g8e9e:a;g<d=e>f?b@eAfBgCgDdEgFeGfHfIcJfKfLeMhNdOfPfehfeedcd e
f"......

The boud rate is correct and I have also tried flashing the board via the NRF Programmer, loading the file 'zephyr.hex' (always keeping the same configuration), instead by VS Code, but it produces the same result.

That seems to be the correct way you described to me to programme the second BC840E board.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Tue, 05 Sep 2023 16:34:17 GMT

Hi,

Which NCS version are you using?

The radio_test sample can be found under samples/peripheral/radio_test in the nRF Connect SDK folder structure.

I would suggest you update the SDK via the Toolchain Manager and then load the radio_test sample from the NCS instead of downloading it from the web.

-Amanda H.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Mon, 04 Sep 2023 13:02:56 GMT

Hi Amanda,

I tried to upload the example you described and which I found within the GitHub repository (github.com/.../radio_test.c ), as within the examples provided by NRF Connect in VS code, there is no radio_test example.
Downloading it and doing "open an existing application" in VS Code gives the following errors during compilation:

1) "No SOURCES given to Zephyr library: lib__libc__common".
2) "implicit declaration of function 'NRFX_MHZ_TO_HZ' [-Wimplicit-function-declaration]"

in the default code found on the net, without making any changes.
How can I proceed to resolve these errors?
The library mentioned in the error is also present in other applications that run without errors.
It should also not be a folder location error.

and also if I try to add the prj.conf file configuration in the building these errors pop up:

1) sys/printk.h: No such file or directory

2) #include errors detected based on information provided by the configurationProvider setting. Squiggles are disabled for this translation unit (C:\Users\leonardo\Downloads\sdk-nrf-master\sdk-nrf-master\samples\peripheral\radio_test\src\radio_cmd.c).

3) cannot open source file "init.h"

4) init.h: No such file or directory

5) cannot open source file "shell/shell.h"

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Wed, 30 Aug 2023 13:32:37 GMT

Hi,

You should make sure the Radio test sample runs on your test target BC840E board and get the boot-up log as my figure. Then, type the commands and get the corresponding return.

[quote user="Amanda"]

[/quote]

Then, use a nRF52840DK to connect the nRF RSSI viewer app.

-Amanda H.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Wed, 30 Aug 2023 11:20:38 GMT

Hi Amanda,

I tried repeating the tests you told me, entering the sequence of commands (start_channel 40 and start_tx_modulated_carrier) but the result is not what I see in your photo.
I attach a photo of the result I see:

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Tue, 29 Aug 2023 13:44:57 GMT

Hi,

[quote user="Leonardo Balocchi"]To set the parameters you specified, do I have to act directly on the source code, or is there an easier way to do it?[/quote]

Try to send the following commands on the top of the nRF Serial Terminal to do a modulated carrier at frequency 2440MHz:

start_channel 40

start_tx_modulated_carrier

Then used an nRF52DK/nRF52840DK connected to the nRF RSSI viewer app (nRF Desktop Connect tool) to confirm that the DUT was transmitting.

You can see the 2440MHz channel rise up.

-Amanda H.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Fri, 25 Aug 2023 09:22:29 GMT

Hi Amanda, about your answer "I recommend that you use the Radio test sample, then select only one channel, like channel 40 as an example. Then put it in TX mode": To set the parameters you specified, do I have to act directly on the source code, or is there an easier way to do it?
I read in the link you sent me about commands that can be entered via the user interface, but I didn't quite understand what it is and how I can use it.

it is not possible to do this directly from nrf Connect Desktop?

And when I try to insert the commands I found under "user interface" (for example print_rx or start_channel) in the link "Radio test (short range)" example you linked me, in the nrf Serial Terminal (nrf Desktop Connect tool), they do not work.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Tue, 22 Aug 2023 14:24:22 GMT

Hi,

As I mentioned in the first reply, RSSI is not the best way to do these types of measurements, there is often some interference or reflections that will change the expected results\outcome. Therefore, I suggest you use sample Bluetooth: nRF Distance Measurement with Bluetooth LE discovery which would also report RSSI value. Are you able to get the log with the sample?

Our expert suspects that you are maybe not setting up the test correctly. For best results and most consistent I recommend that you use the Radio test sample, then select only one channel, like channel 40 as an example. Then put it in TX mode. This will give them a continuous +0dBm TX stream on channel 40. Then on the receiver side, connect nRF52840DK to the computer and then use the RSSI Viewer app in nRF Connect for Desktop. You should be able to see what channel spikes when you enable the transmitter(BC840E board).

-Amanda H.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Tue, 22 Aug 2023 12:50:49 GMT

However, I programmed the two boards as you told me, but the main problem persists:

"I placed the two boards 1m apart, and for the 2.4 GHz frequency I should have a path loss of 40.04 dB.
On the BC840E board I connected a 5 dBi gain antenna.
Knowing that the nRF52840 in transmission I set it for 0 dBm and that the antenna gain on the nRF52840 is 0 dBi, I should see about -35 dBm of RSSI, the problem is that the measured RSSI is about -2 dBm."

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Tue, 22 Aug 2023 08:25:09 GMT

Hi,

how can i check the register of the BC840E evaluation board? i can only connect to it via the nRF52840DK to load the programme, as you saw above.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Mon, 21 Aug 2023 14:29:21 GMT

You can check the device log on the BC840E to see whether you get the expected log or not.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Mon, 21 Aug 2023 13:57:23 GMT

Okay, and how do I check that the programme has been loaded correctly on the BC840E?
(I don't think it's possible to do this via the nRF Connecto for Desktop programmer, because it doesn't see that board)

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Mon, 21 Aug 2023 13:11:16 GMT

yes.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Sat, 19 Aug 2023 15:23:16 GMT

Hi Amanda,

As I told you in a few replies above, using the nrf Connect Programmer, what I can see is only the nRF52840 DK board, although they are both connected and verified as you told me with the j-link Commander:

If I load the zephyr.hex file into the nRF52840DK, will it also automatically load into the BC840E board (even if it is not detected by the nrf Connect Programmer)?

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Fri, 18 Aug 2023 16:17:38 GMT

You can use nRF Command Line tool or nRF Connect Programmer to program the image.

[quote user="Leonardo Balocchi"]nrfjprog -f NRF52 --program zephyr.hex --chiperase --reset"[/quote]

-Amanda H.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Fri, 18 Aug 2023 15:23:36 GMT

how? do i have to open the normal command prompt (i.e. not the J-link commander)?

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Amanda Hsieh — Fri, 18 Aug 2023 15:16:15 GMT

You can start to program it.

RE: measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi — Fri, 18 Aug 2023 15:13:52 GMT

Hi Amanda,

OK, the 2 boards are connected to the computer's usb and connected to each other via the '10-conductor cable for connection'.
I opened J-link Commander and it returns exactly what you showed me in the reply above.
Now what is the next step?