RE: BLE GATT questions and large transfer

FormerMember — Thu, 22 Dec 2016 14:54:05 GMT

1) From what I understand, in a worst case scenario, the firmware on the devices should be updated every 10s, i.e, transfer of data from the central (Android, iOS) to the peripheral (the device). In that case, the best working solution is to use regular writes of 20 bytes. However, depending on the connection interval and the number of packets per connection interval supported by the central, it may not be possible to transfer 60 kB of data within 10 s. This blog post shows typical number of packets per connection interval for various phones.

Another option could be to use data packet length extension (DLE), where the maximum packet length is 255 bytes. However, currently, there is only a few phones that support DLE.

It is also possible to look into Bluetooth 5, it was released two weeks ago and is currently supported by very few devices. Bluetooth 5 allows higher transfer speed than Bluetooth 4.2.

2) I would think it is "allowed" to do what you describe, for instance have a heart rate profile and some extra services in addition heart rate profile. It could be regarded as a device with two profiles.

RE: BLE GATT questions and large transfer

schef — Thu, 15 Dec 2016 10:20:02 GMT

It is not possible with BLE specification although s132 has increased the speed.

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