Project survey

[DCsaba]

Hello,

I am thinking of implementing a project in which if we use NFC to perform Bluetooth quick pairing and create a Bluetooth connection between a phone and a Raspberry PI, and finally we can send system-level notifications from the Raspberry to the phone (for both Android and iOS) without downloading any kind of application (this would be very important).

The project would be based on a Raspberry PI 5 and an nRF52840 Bluetooth 5.0 Evaluation Kit module.

My questions would be:
  - can the project be solved with the listed elements?
  - approximately at what distance could I maintain contact with these devices?
  - can the module be configured so that it can establish a connection and send messages to Android and iOS systems at the same time (without an application), or is it worth using two separate modules due to the different protocols?

Thank you in advance for the answers,

Best regards,

Csaba Dajka

[ovrebekk]

Hi Csaba

  - can the project be solved with the listed elements?

The main challenge I see with your proposal is having the phone show system level notifications without needing any apps to be installed. This is not supported in either Android or iOS. 

Typically you need an app to be installed, and the app needs to run as a service in the background to scan for your device and connect to it when needed. Then this service can trigger notifications on the phone based on input from the Bluetooth device. 

  - approximately at what distance could I maintain contact with these devices?

Range is very much dependent on the environment, and also the RF performance of the phone and the nRF52 device, but typical range is around 10-20m. 

- can the module be configured so that it can establish a connection and send messages to Android and iOS systems at the same time (without an application), or is it worth using two separate modules due to the different protocols?

The nRF52840 can easily connect to two phones at the same time, yes. But again getting notifications without an app is not possible. 

Bluetooth HID devices can be used on phones without an app, but HID devices can not trigger notifications, they can only emulate typical HID devices like keyboards and mice. 

Best regards
Torbjørn

[DCsaba]

Hi Torbjørn,

Thank you very much for the quick and detailed answers!

Then the connection could be solved with the listed devices and could be maintained at a relatively long distance, would the problem be only with sending notifications?

According to the best of my knowledge, the system can send push notifications to iOS devices if there is a BLE connection, on which notifications can then be sent to phones via the ANCS protocol.

I don't want to argue, I'm not an expert on the subject, I'm happy to be corrected if I'm wrong.

Thank you in advance for the answers,

Best regards,

Csaba Dajka

[ovrebekk]

Hi Csaba

The problem is in triggering notifications on the phone side, yes. 

DCsaba said:

According to the best of my knowledge, the system can send push notifications to iOS devices if there is a BLE connection, on which notifications can then be sent to phones via the ANCS protocol.

Thanks for bringing this up, I must admit I didn't really consider ANCS (we don't get many questions about it these days). 

The problem of ANCS, in addition to not being natively supported on Android, is that it is designed to show notifications on the peripheral device, not on the phone. ANCS basically allows you duplicate every notification received on the iPhone on a connected Bluetooth device, typically a smart watch. Then you can for instance see easily on your watch if you are receiving a call on the phone. 

To my knowledge you can not have the peripheral device trigger custom notifications on the phone when using ANCS. 

Best regards
Torbjørn