This makes it possible for external services to subscribe (through
Redis) for realtime events. E.g. a create, update or delete device event
could trigger an external synchronization.
In case the decoded payload contains random keys the auto-detect
measurements feature will add new measurements for each uplink. With
this option it is possible to turn auto-detection off to avoid
polluting the database with many measurements.
Closes#42.
This includes:
* Changing the modulation parameters to its own type.
* Changing the timing parameters to its own type.
* Change the gateway_id to string. As the json encoding for bytes fields
is base64, this was confusing some users.
* Change the uplink / downlink id to uint32 from uuid. A string
representation of the UUID field (for the same reason as the gateway
id) would consome quite some additional bytes. An uint32 provides
sufficient uniqueness for the purpose of uplink / downlink.
