Interworking possibility between devices using or not SoftDevice?

[LuisSilva]

Hi,

I have doubts regarding a given scenario that probably some of you have already faced before. Since I'm new to BLE and Nordic, probably my doubts may be basic too.

Scenario: New development uses SoftDevice S132 and devices using BLE 5.1. However, there are already some legacy devices from BLE 4.0 that need to be supported too but are not using SoftDevice (using instead a proprietary implementation for GAP and GATT). The goal is to minimize (as much as possible) the development for the legacy devices while supporting still both new and legacy devices.

Question#1) - It is really possible (and easy) to have (Central) devices using SoftDevices and some of the (Peripheral) devices not using SoftDevice?

Note: some of the legacy devices have multi roles, i.e., behave both as Peripheral and as Central but never using softDevice.

Question 2) - Are there any guidelines/threads that you know of for the support of such scenario?

Thanks,

Luis

[Jared]

Hi,

 

Question#1) - It is really possible (and easy) to have (Central) devices using SoftDevices and some of the (Peripheral) devices not using SoftDevice?

 This shouldn't be a issue, as long as the legacy devices follows the BLE specification. Just as Nordic devices functions with non-Nordic devices that follows the BLE spec.  Features that were introduced in newer versions are of course not supported in legacy. 

Question 2) - Are there any guidelines/threads that you know of for the support of such scenario?

 Not sure exactly what tutorial that is needed in this scenario. It shouldn't be any different as for other scenarios as long as the device on the other hand follows the BLE spec. 

regards

Jared 

[LuisSilva]

Hi Jared,

Thanks for the feedback, which has been really helpful guiding me in the analysis/evaluation that I'm still doing and is taking time because I'm still learning the old legacy code.

I'm  still not sure whether the legacy implementation itself is 100% BLE specification compliant, something that would surely make the interworking not feasible. However, I'm starting to suspect that probably there was a reason for not using SoftDevice but instead follow a proprietary implementation approach.

The legacy support is for BLE 4.1 (not 4.0) using nRF51822 and it already supports multi-role (same device acting as Central to another Peripheral and as Peripheral to a Central device).

My current understanding (that may not be correct, hence I kindly require your feedback again):

- BLE 4.1 already supports multi-role, although its support is Optional (not Mandatory).

- Both SoftDevice S110 and S120 do not support concurrent multi-role Central and Peripheral, exactly the one that is supported in legacy code.

Question#1: Is my current understanding (shown above) correct?

Question#2: Is it possible to somehow use SoftDevice S132 to connect to nRF51822, even if having to do (if possible) some special SoftDevice configurations?

Thanks,

Luis

[Jared]

Hi,

LuisSilva said:

I'm  still not sure whether the legacy implementation itself is 100% BLE specification compliant, something that would surely make the interworking not feasible.

 Yes, you should find out if your legacy implementation is BLE compliant or not. 

LuisSilva said:

- Both SoftDevice S110 and S120 do not support concurrent multi-role Central and Peripheral, exactly the one that is supported in legacy code.

Softdevice S110 v2.0 and S120 v2.0 supports Multirole, which means that they can act as more than one GAP role simultaneously. But they only support one side of the connection. Meaning, S120 only supports GAP Central and Observer, while S110 only supports GAP Peripheral and Broadcaster. Which means that they can do multirole, but in S120 it only be Central and Observer simultaneously, and S120 can only be Peripheral and Broadcaster simultaneously. 

 

LuisSilva said:

- Both SoftDevice S110 and S120 do not support concurrent multi-role Central and Peripheral, exactly the one that is supported in legacy code.

 When you refer to legacy I've understood it so that you're referring to your proprietary BLE implementation. I therefore can't comment on what that supports or not. Please clarify this. 

LuisSilva said:

Question#2: Is it possible to somehow use SoftDevice S132 to connect to nRF51822, even if having to do (if possible) some special SoftDevice configurations?

 S132 is made for the nRF52 series. You can connect to a nRF51 that runs for example S130 with a nRF52 that runs S132. 

I'm afraid that I might not have understood you correctly. Please try to clarify anything if I'm wrong in any of my assumptions. 

regards

Jared

[LuisSilva]

Hi Jared,

Thanks a lot for your support!

Your answers/feedback have been really really helpful and I now have my doubts clarified.

Thanks again,

Best regards,

Luis 

[Jared]

Ok,

btw:

I meant to write 132 for nRF52 in my previous answer. :)