Getting Started with Android BLE blog post #15
Conversation
| //App service UUID | ||
| val chatDiscoveryServiceID = UUID.fromString("42332fe8-9915-11ea-bb37-0242ac130002") | ||
|
|
||
| //Gatt service message characteric ID used | ||
| val chatMessageCharacteristicID = UUID.fromString("43eb0d29-4188-4c84-b1e8-73231e02af95") | ||
|
|
||
| //UUID to confirm device connection | ||
| val confirmCharacteristicID = UUID.fromString("f0ab5a15-b003-4653-a248-73fd504c128f") |
There was a problem hiding this comment.
While the values are the same, the names and comments of these UUIDs should match what's in the iOS app.
Specifically, the second UUID is used as a service ID rather than a characteristic; the third UUID is a a chat characteristic where messages are written, rather than playing any sort of "confirmation" role.
| chatMessageCharacteristicID, | ||
| BluetoothGattCharacteristic.PROPERTY_WRITE, | ||
| BluetoothGattCharacteristic.PERMISSION_WRITE | ||
| ) |
There was a problem hiding this comment.
Is the app intended to be compatible with the iOS one? The GATT hierarchy is different so I don't think it would work.
Specifically, iOS uses one service UUID to locate other peers (discovery phase), then a second UUID to negotiate a chat connection. Then it has a single characteristic to exchange/notify chat message, both for write & notify.
| BluetoothGattCharacteristic.PERMISSION_WRITE | ||
| ) | ||
| gattService.addCharacteristic(gattCharacteristic) | ||
| gattService.addCharacteristic(confirmCharacteristic) |
There was a problem hiding this comment.
This confirmCharacteristic isn't queried or used on the central side.
This is the porting of the iOS BLE chat app, on Android. There is a PR in the getditto/website-2021 for the blog post, which is linked in the README