Questions about Nordic Distance Measurement library sample

RE: Questions about Nordic Distance Measurement library sample

Simonr — Mon, 22 Jul 2024 09:14:40 GMT

It doesn't seem like the ranging specifically increases over time though, and after the 4 second ranging there seems to be a new 1 second ranging, so they seem random, rather than decreasingly slower. Can you provide some more information on how you do the testing? How far between the two devices is it when testing, and in what kind of environment are you testing. Also, is the Dongle doing anything else in software except the distance measurement ranging that might take a lot of time?

Best regards,

Simon

RE: Questions about Nordic Distance Measurement library sample

Naeem Maroof — Tue, 16 Jul 2024 12:51:27 GMT

Hi,

Simon is out of office, and he will be with you when he is back on Monday.

Apologies for the inconvenience.

Regards,

Naeem

RE: Questions about Nordic Distance Measurement library sample

June11 — Sun, 07 Jul 2024 05:56:14 GMT

An output interval of 8s is too long for me.

My current configuration is

CONFIG_DM_HIGH_PRECISION_CALC=n

CONFIG_DM_MIN_TIME_BETWEEN_TIMESLOTS_US=8000

RE: Questions about Nordic Distance Measurement library sample

Simonr — Thu, 27 Jun 2024 13:04:12 GMT

I've not been able to find anything on a ranging increasing in time, and I think this is just the random delay from BLE advertisements trigging. The count of time you have set up seems to be rather random.

Best regards,

Simon

RE: Questions about Nordic Distance Measurement library sample

June11 — Thu, 27 Jun 2024 02:47:48 GMT

[quote userid="132718" url="~/f/nordic-q-a/112374/questions-about-nordic-distance-measurement-library-sample/490109"]

Hi,

I have solved the problem of imbalanced output data. But now I run into another problem, I find that the number of outputs becomes less as time goes on, what might be the cause of this?

I found similar questions in this ticker, but couldn't find the answer.

devzone.nordicsemi.com/.../nrfconnect-sdk-nrf_dm-example-with-dedicated-roles-with-several-reflectors-and-one-initiator-degrades-with-time

[/quote]

The fifth question means that when the device is just powered on, the initiator's ranging frequency is 2 per second. After 30 minutes, the frequency of the initiator's output log will slow down, and on average only one ranging data is output every 5s.

The graph below shows the measured ranging output frequency after 30 minutes

RE: Questions about Nordic Distance Measurement library sample

Simonr — Wed, 26 Jun 2024 11:50:25 GMT

1. To make a device just work as a scanner or advertiser you need to change the bt_sync_init() function to only use advertising or scanning so that the device won't do both of them.

2. I'm not sure I understand what you mean here, but the reason an advertises might only connect to one base station is likely because it decides to pair and sync up to the first device it connects to, and if that device always is in range that is what it will connect to. You can change the way the connections are handled to disconnect and "forget" that device so that it will connect to another one next time (most likely). You can also turn off the initial central it connected to so that the tag will connect to a new one

3. Good. High precision will only be necessary if you have the computing to spare and need the extra accuracy.

4. One timeslot will be the time allocated for the radio to do a certain task, so the part between the red arrows in your drawing I believe.

5. Can you be more specific on what you mean about the frequency of ranging decreasing? From what to what exactly?

Best regards,

Simon

RE: Questions about Nordic Distance Measurement library sample

June11 — Mon, 24 Jun 2024 15:41:00 GMT

Hi，

1、I've looked at the documentation, but I haven't found an answer on how to just set as a scanner；

2、 For the balance issue, I refer to the practice of other tickets and make limits in the application；

3、I'll try to test the parameters you suggested，CONFIG_DM_HIGH_PRECISION_CALC=n；

4、This figure was drawn by me based on the official document, and it is what I understand, but I don't know if it is correct or not. I don't quite understand what TIMESLOT means；

5、The device distance remains the same, Over time, the frequency of ranging decreases.Any suggestions on this issue？

Best regards

RE: Questions about Nordic Distance Measurement library sample

mathiaso — Mon, 24 Jun 2024 14:36:47 GMT

Hi.

[quote user=""]

1. I have 8 devices, all within communication range, 4 as base stations and 3 as tags. The base station is the reflector, which is achieved by commenting this code：

//if (peer_supported_test(info->addr)) {

I want to let the tag be the initiator only。What do I need to change？

[/quote]

Have you looked at the documentation describing the nRF Distance Measurement sample and how to use the Distance Measurement Library?

[quote user=""]

2. I found that the tag sometimes only tests with certain base stations, and I want to test the tag with each base station, so that the measurement data of the tag is relatively average. Is there any better implementation method?

[/quote]

Is this what you figured out yourself?

[quote user=""]3. Test the two boards separately, and find that the measurement data can be output once per second when the distance is close. When the distance becomes longer, the output data will become slower. What parameters do you need to change?[/quote]

There are several parameters deciding how fast output will be ready. Distance is one of these parameters so it is natural that it requires more time as the distance increases. If you've set CONFIG_DM_HIGH_PRECISION_CALC=y and can sacrifice precision for a higher output data rate, you can set it =n, as described in CONFIG_DM_MIN_TIME_BETWEEN_TIMESLOTS_US.

[quote user="June11"]

For multiple device measurements, is it a one-time synchronization followed by device by device measurements?

I'm not sure TIMESLOT meant the pink arrow part or the blue arrow part.

[/quote]

Could you please point to the source of this figure?

Best regards,
Mathias

RE: Questions about Nordic Distance Measurement library sample

mathiaso — Mon, 24 Jun 2024 14:36:32 GMT

Hi.

[quote user=""]

1. I have 8 devices, all within communication range, 4 as base stations and 3 as tags. The base station is the reflector, which is achieved by commenting this code：

//if (peer_supported_test(info->addr)) {

I want to let the tag be the initiator only。What do I need to change？

[/quote]

Have you looked at the documentation describing the nRF Distance Measurement sample and how to use the Distance Measurement Library?

[quote user=""]

[/quote]

Is this what you figured out yourself?

[quote user="June11"]

For multiple device measurements, is it a one-time synchronization followed by device by device measurements?

I'm not sure TIMESLOT meant the pink arrow part or the blue arrow part.

[/quote]

Could you please point to the source of this figure?

Best regards,
Mathias

RE: Questions about Nordic Distance Measurement library sample

June11 — Sun, 23 Jun 2024 09:47:58 GMT

Hi,

I have solved the problem of imbalanced output data. But now I run into another problem, I find that the number of outputs becomes less as time goes on, what might be the cause of this?

I found similar questions in this ticker, but couldn't find the answer.

devzone.nordicsemi.com/.../nrfconnect-sdk-nrf_dm-example-with-dedicated-roles-with-several-reflectors-and-one-initiator-degrades-with-time

RE: Questions about Nordic Distance Measurement library sample

June11 — Sun, 23 Jun 2024 08:22:14 GMT

Hi，
I understand the parameters in this way, and I don't know if my understanding is correct.

For multiple device measurements, is it a one-time synchronization followed by device by device measurements?

I'm not sure TIMESLOT meant the pink arrow part or the blue arrow part.