What causes the sensor Tag to send measurements?

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Anonymous
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I just downloaded the Android code and started reviewing it.  One question that also comes to mind, what causes the sensor tag to send the measurements?  Is there some kind of message sent to the sensor tag to get a response, or does the sensor tag use a fixed timer to send periodic measurement reports once paired with a BLE device?

In general, there doesn't seem to be a comprehensive interface document that rigorously defines what goes between the sensor tag and the application.

1 Solution
Anonymous
Not applicable

Very good question and important to know (e.g. if you debug):

BLE knows Notification and Indications (first is unreliable, second is reliable due to acknowledge from receiver/client expected).

If a client (Android Smartphone) has subscribed to a Notification or Indication, the server (BLE device) will send ONLY if a NEW value is there.
Therefore, it can happen: if the sensor value does not change = nothing sent and nothing received on client.

A periodic timer (no idea) in case of very fast changes - I think the server/device can decide, e.g. every 1 second as fastest update speed, but still: just if value is new and changed.

If sensor value will never be changed - nothing sent and updated on client.

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1 Reply
Anonymous
Not applicable

Very good question and important to know (e.g. if you debug):

BLE knows Notification and Indications (first is unreliable, second is reliable due to acknowledge from receiver/client expected).

If a client (Android Smartphone) has subscribed to a Notification or Indication, the server (BLE device) will send ONLY if a NEW value is there.
Therefore, it can happen: if the sensor value does not change = nothing sent and nothing received on client.

A periodic timer (no idea) in case of very fast changes - I think the server/device can decide, e.g. every 1 second as fastest update speed, but still: just if value is new and changed.

If sensor value will never be changed - nothing sent and updated on client.