How a central BLE device can read data from multiple BLE devices simultaneously?

RE: How a central BLE device can read data from multiple BLE devices simultaneously?

awneil — Wed, 18 Sep 2019 14:15:46 GMT

Take a look at the multi-link example mentioned earlier.

RE: How a central BLE device can read data from multiple BLE devices simultaneously?

prayuktibid — Wed, 18 Sep 2019 11:29:51 GMT

Thank you for your reply.

Please give a brief idea about the possible firmware architecture for my case.

RE: How a central BLE device can read data from multiple BLE devices simultaneously?

awneil — Wed, 18 Sep 2019 07:57:17 GMT

[quote userid="83461" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously/210284"]Using RTOS, threading we can achieve parallel processing[/quote]

Not on a single core CPU, you can't !

You achieve the illusion of parallel processing by switching between tasks/threads - only one is actually active at a time.

[quote userid="83461" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously/210284"]data might lose cause when the central device switching from one peripherals device to another peripherals device if another sensor data will come on that instance[/quote]

So you have to buffer the data while waiting to send it.

These are all basic concepts - not really specific to BLE or Nordic.

RE: How a central BLE device can read data from multiple BLE devices simultaneously?

prayuktibid — Wed, 18 Sep 2019 07:16:41 GMT

[quote userid="6462" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously/210239"]Do you have experience with microcontrollers in general?[/quote]

Yes, I have.

[quote userid="6462" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously/210239"]Unless the sensors need to be in different locations, why not connect all the sensors to one nRF52 ... ?[/quote]

Yes, each sensor is in a different location so I need on nRF52 for each sensor.

[quote userid="6462" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously/210239"]Do they really need to be simultaneous?[/quote]

Actually, in my case, each sensor's data is important and the same priority.

Let's assume in a case.. when the central device talking with an nRF52 in that time another nRF52 has to talk with central devices. In that case, either central device will stop talking with the first nRF52 and it will start talking with the second nRF52 or it will continue talk with the first one thereafter it will talk with the second one.

But in both cases, data might lose cause when the central device switching from one peripherals device to another peripherals device if another sensor data will come on that instance then the current data will overwrite the previous data. If the number of peripherals device much then the probability of data loss is high. I am thinking of worst-case scenarios.

But in normal, sensor data will not come within a fraction of second or microsecond and if the central device's throughput then it can be overcome.

Using RTOS, threading we can achieve parallel processing. I have asked the question in the wrong way, I am sorry for that.

[quote userid="6462" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously/210239"]The SoftDevice can support up to 20 simultaneous connections - how many do you need?[/quote]

I need 8 device

RE: How a central BLE device can read data from multiple BLE devices simultaneously?

awneil — Tue, 17 Sep 2019 21:05:58 GMT

[quote userid="6462" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously/210239"]Any microcontroller can only do 1 thing at a time; but they can do things in quick succession - which is usually "close enough"[/quote]

Which is just like the old fashioned way where the sensors would have dials on them, and you would take the readings manually - visiting each one in turn.

Then you would say that those were the reading taken "at the same time" ...

RE: How a central BLE device can read data from multiple BLE devices simultaneously?

awneil — Tue, 17 Sep 2019 21:03:05 GMT

[quote userid="83461" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously"]I am a very beginner in the BLE domain[/quote]

Do you have experience with microcontrollers in general?

[quote userid="83461" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously"]Each peripheral device collecting data from the different sensors[/quote]

Unless the sensors need to be in different locations, why not connect all the sensors to one nRF52 ... ?

[quote userid="83461" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously"]As much I know that I a central device can communicate with multiple devices but I can't talk simultaneously.[/quote]

Do they really need to be simultaneous?

Any microcontroller can only do 1 thing at a time; but they can do things in quick succession - which is usually "close enough".

[quote userid="83461" url="~/f/nordic-q-a/52257/how-a-central-ble-device-can-read-data-from-multiple-ble-devices-simultaneously"]How many peripherals devices can talk with a central device?[/quote]

The SoftDevice can support up to 20 simultaneous connections - how many do you need?

The SDK contains a multi-link example:

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.3.0/ble_sdk_app_multilink.html

But, as a "very beginner", I would suggest that you don't jump straight into that - spend some time with the basic examples first to gain familiarity with BLE in general, and the Nordic product & tools in particular ...