I played with a BLE device recently (VSN V.BTTN) and was able to get interesting functionality with the button and a Raspberry Pi. However, I still have a few questions regarding the device pairing behavior:

1) Once the pairing occurred, am I correct to assume that most BLE device will not even try to ping each other to know if they are still there? The rational behind that would be to save batteries of both devices?

2) In that case, my watch sends a notification that data is available to be fetched. Does it ever know that the notification was received via an knowledge or the only way to know is when the host device sends a data request?

3) Assuming that the watch goes out of the range of the raspberry pi. Will it lose systematically the pairing?

4) In general, do you need to go through pairing each time you shut down one of the device? Is there a way to simply avoid that?

  • \$\begingroup\$ 3 and 4, it shouldn't. That would be a very bad design. The pairing should stick unless the device has volitale memory and loses power. Most designs would save the pairing information in an eeprom or other persistent storage. \$\endgroup\$ – Passerby May 22 '18 at 16:48
  • \$\begingroup\$ I'm pretty sure that the watch does it natively. My current implementation omitted that part because of the pedagogic nature of that project: I didn't know anything about BLE before that project and I still don't know much. \$\endgroup\$ – Simon Marcoux May 22 '18 at 17:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.