BLE RELAY EXAMPLE

RE: BLE RELAY EXAMPLE

tesc — Tue, 29 Oct 2019 16:03:23 GMT

Hi,

According to the Heart Rate Profile (found in list of GATT Specifications from bluetooth.com), "The Heart Rate Sensor shall instantiate one and only one Heart Rate Service" This means the peripheral and the relay can only provide one instance of the Heart Rate Service, and so you cannot relay measurements in one service and provide measurements from the relay in another service.

There are no such limitations on the Collector Role, so you could rewrite the collector to connect to and collect data from all 6 Heart Rate Sensors directly.

Another alternative could be to use a custom service for the relay, for sending heart rate measurements from multiple devices. You can do that if you control the relay and the collector, so that you can make a vendor specific service for that.

Regards,
Terje

RE: BLE RELAY EXAMPLE

Hermes — Fri, 25 Oct 2019 19:07:18 GMT

From the diagram we can see there are three devices and each played a different role.

Understand a peripheral device provides its sensor data, and it is pass to relay. Can the relay device generate (connected with same kind of sensor) its own data, and then pass packet 1 (eg HR 110bpm) from peripheral, and packet 2 (HR 70bpm) of itself, to the collector? Can a collector collects these two packets?

Let me elaborate Q3 (same coin different side). For example, we have 6 devices, and each is connected to same kind of HR sensor. We will like to program 3 of these devices to measure HR as peripherals and it is connected to a relay_A. And another 2 devices is also programmed to measure HR as peripherals but these two pass data to relay_B. The last device is used to collect two 5 sets of data, 3 sets from relay_A and 2 sets from relay_B. Is this possible as we used our multi-peripheral, multi-link, and relay combine?

RE: BLE RELAY EXAMPLE

tesc — Fri, 25 Oct 2019 15:45:26 GMT

Hi,

From what I understand, the device should only provide one data set through one service. That means if it should both generate data itself and relay data from a different device it should provide that as two separate services.

Then in question 2 it becomes a new question if the collector is getting two sets of data from the relay, or if it is connected to two different peripherals at the same time, getting one set of data from each. Both alternatives should be possible.

I am not quite sure what you mean in question 3. Can you elaborate?

Regards,
Terje

RE: BLE RELAY EXAMPLE

Hermes — Wed, 23 Oct 2019 12:27:53 GMT

Hi Terje,

Thanks for your prompt reply again. Noted there is a spec on Collector role. i will look into it.

Let me try to be more specific here, at least for the other parts of my question.

My first question is whether a "relay" node able to carry its own senor data while he perform the role as a "relay". From this diagram, it seem there are two nodes each has its own sensor. To put it simpler, we say, there is only one sensor, HR, on each node.

My second question is whether this "collector" node in BLE Relay Example able to receive sensor data from both peripheral and relay. Please note there are two set of data going to collector but only one connection. If this is possible, can you briefly explain how?

i suppose my third questions arise when you provide me the idea of a multi-link collector. Can i have a few more "relay", not just more peripherals, to be connected to a collector?

Appreciate your kind advice soon, pls.

RE: BLE RELAY EXAMPLE

tesc — Tue, 22 Oct 2019 08:43:19 GMT

Hi,

In the BLE Relay Example, "collector" refers to any device implementing the Collector role for the Heart Rate Profile. That profile is specified by the Bluetooth SIG.

For instance, you can use our BLE Heart Rate Collector Example. That example only connects to one peripheral. To see how to connect to multiple peripherals you can have a look at our BLE Multi-link Example.

Regards,
Terje

RE: BLE RELAY EXAMPLE

Hermes — Tue, 22 Oct 2019 05:41:17 GMT

Hi tesc, Thanks for your prompt reply.

i understand i have to write my own sensor related code for the sensor to work on the relay.

Can i just verify whether the collector (central) in BLE Relay Example; or any other example, able to collect sensor data from two individual two nodes? For my case, Node A - a peripheral with a sensor and Node B - a relay with another same sensor.

Is the collector refer to, in this case, either another board or android phone?

Rgds

RE: BLE RELAY EXAMPLE

tesc — Mon, 21 Oct 2019 08:27:26 GMT

Hi,

The BLE Relay Example only relays sensor data. Yes, it can collect from one heart rate peripheral and from one running speed peripheral, and relay that to one central.

You may of course modify the example as you wish, for instance let sensor readings originate from the relay device. Note that the BLE peripheral examples in the SDK does not use sensors, they show the BLE side of things and only emulate sensor data. Connecting an actual sensor and writing the sensor related code is something you would have to do yourself.

Regards,
Terje

RE: BLE RELAY EXAMPLE

Hermes — Sat, 19 Oct 2019 08:32:26 GMT

Hi everyone, am about to start this project; using Experimental: BLE Relay Example.

Can i just verify whether the relay (ie Node B) carry it own sensor as well? i understand the relay help to collect data from its peripheral(Node A) then send to collector(aka central).

As gathered here, the relay can be both peripheral and central. Am i right to say, the collector will collect two set of data, from Node A and Node B each?

RE: BLE RELAY EXAMPLE

tesc — Thu, 30 Aug 2018 12:41:27 GMT

Hi,

Sorry for the delay.

Do you have problems only with the Running Speed and Cadence Application, or are there other applications that you cannot scan for either? Please note that the application only advertises for 3 minutes after it has started.

Before you put the SoftDevice and application onto the board it is wise to erase flash (for instance using "nrfjprog -e"), in case there are UICR settings or data stored in other regions of flash.

Also, what SoftDevice (including full version number) are you using?

Regards,
Terje

RE: BLE RELAY EXAMPLE

GeorgeBlue — Mon, 27 Aug 2018 02:20:19 GMT

3. Is that the "running speed sensor" Example will not Advertising the Device Name "Nordic_RSC"? I cann't found on nRF Connect and Sniffer log. (SDK15.0.0)

Yes, I can't SCAN DUT from my smartphone "Nordic_RSC" in that example.

RE: BLE RELAY EXAMPLE

tesc — Thu, 23 Aug 2018 16:51:23 GMT

Hi,

The SDK supports multiple connections, yes. And you can do processing of information received over one connection before sending it on another connection. Also, the peripheral and central roles can work concurrently, which means you can stay connected both as peripheral and central at the same time. Please note that it requires programming from your part, i.e. we provide the SDK with APIs and documentation, and you use that in order to write your application code. We provide examples so that you have a starting point.

I do not quite understand your question 3. Are you wondering how to make sure the sensor connects to the relay and not to the smartphone or nRF Connect directly? Or are you trying an example but you cannot find it on smartphone or nRF Connect?

Regards,
Terje

RE: BLE RELAY EXAMPLE

GeorgeBlue — Thu, 23 Aug 2018 02:18:22 GMT

Hi, Tesc,

Thanks for you replay.

Actually, I hope my programming device can be as Role Central and Peripheral.

1. When device switch to Role as Peripheral, it could be connected with SmartPhone(Central) and communicate with iOS or Android App.

2. When device switch to Role as Central, I hope device can receiving data from Peripheral and also process the data in local device. I hope this device able to support more than two Peripheral.

I have finished Experimental: BLE Relay Example, this feature seen meet my request, and I have some question.

3. Is that the "running speed sensor" Example will not Advertising the Device Name "Nordic_RSC"? I cann't found on nRF Connect and Sniffer log. (SDK15.0.0)

4. Continuous the Q3, is that the "running speed sensor" Example propose to Hide the Device Name, something like invisible SSID, do not hope the Smart Phone can access into DUT.

5. If I hope we support more than two device, is that possible in this SDK, something like increase NRF_BLE_GATT_LINK_COUNT and add more services.

RE: BLE RELAY EXAMPLE

tesc — Wed, 22 Aug 2018 09:32:28 GMT

Hi,

The BLE Relay Example is a multirole example, where the relay acts both as central and as peripheral. It acts as central in order to scan for and connect to a heart rate sensor and to a running speed sensor. It acts as peripheral in order for a collector to connect to it. It relays the heart rate values and the running speed values from the sensors to the collector, without doing any calculations on them.

The relay example can connect to one heart rate sensor and one running speed sensor, and it can be connected to from a collector. Our heart rate sensor and running speed sensor examples connect to one central, which means they connect to one relay only.

If you need more connections than that then you must modify the example. For how to do multiple connections you may have a look at the multiperipheral eample and the (central) multi-link example. The current SoftDevices allows for up to 20 connections total.

Regards,
Terje

RE: BLE RELAY EXAMPLE

GeorgeBlue — Wed, 22 Aug 2018 03:37:48 GMT

In Experimental: BLE Relay Example.

1. Is that the relay BLE device able to received Peripheral's data and process the data? When forwarding the data to central.

2. Is those Peripheral devices should paring with Relay Device first? Finally step is relay device paring to central device? If yes that seen not a friendly to normal user.

3. Is that Relay device role is central device?

4. How many Peripheral device can be relay out to central? (MAX)

RE: BLE RELAY EXAMPLE

tesc — Mon, 11 Jun 2018 12:14:41 GMT

Hi,

I am a little confused as to what example you are referring to. Are you testing the Experimental: BLE Relay Example from the nRF5 SDK v15.0.0? That is not a Bluetooth Mesh example, it is a Bluetooth Low Energy example. It sets up standard BLE connections, and I suspect if you power on several relays then there is nothing stopping them from connecting to each other in a loop, or something other weird. The reason for that is they simply search for a device with the correct BLE service and connects, and then there is no control of the resulting network topology when having multiple instances in the same area.

If you want a Bluetooth Mesh network then you should have a look at the examples in the nRF5 SDK for Mesh v2.0.1 instead. Once two Mesh nodes are configured to talk to each other they can send messages over the Mesh network regardless of network topology.

If you want a network based on BLE, then you must make sure that the relays connects correctly to each other. That means you most likely "hard code" the network topology, so that all communication follows the same path.

It is hard to tell which one of the above solutions is best for your use case.

Regards,
Terje