Device can be "handshaked" on first payload about smartcitizen-api

[pral2a]

TL;DR

Yes, the 'Hello' protocol is no longer needed in our current firmware setup.

Detailed Explanation:

1. Handshake:
   Initially, 'Hello' confirmed device communication independently of sensor data, in case it was not available: i.e. sensors are warming up.

2. Heartbeat:
   The 'Hello' served as a device health check when sensors were inactive: i.e. sleep mode for power savings

3. Security:
   A plan for 'Hello' to aid in periodic key exchanges (i.e. Diffie-Hellman) to increase security: i.e. current token is very weak. Current MQTT over SSL and longer device tokens might be sufficient.

Conclusion:
Given these developments, maintaining the 'hello' handshake isn't justified in our current firmware system architecture. We can always come back to it or merge it with ‘hardware_info’.

[oscgonfer]

I confirm that this is now handled in @timcowlishaw #246 PR

We should keep @pral2a things in mind in #286 though. @timcowlishaw could you add a small mention to it?