What devices send.
WHAT EVERY MESSAGE NEEDS
A device identifier A timestamp The measurement and its units A schema or format version
WHY THE VERSION MATTERS
Devices in the field will run different firmware, and the platform must handle all of them.
WHAT TO INCLUDE FOR RELIABILITY
A sequence number, revealing gaps A message identifier, enabling deduplication
WHY SEQUENCE NUMBERS MATTER
They show what was lost, which silence does not.
WHAT FORMATS SUIT
Compact binary with a defined schema, for constrained links Structured text, where bandwidth permits and readability helps
WHAT TO DEFINE
The schema, versioned and documented.
WHY
Devices and platform are developed separately and must agree.
WHAT TO AVOID
Field names longer than necessary on constrained links Floating point where integers with a known scale suffice Nested structures adding overhead Units left implicit
WHY UNITS ESPECIALLY
Implicit units cause errors that are invisible until something behaves absurdly.
WHAT TO PLAN
Schema evolution: adding fields without breaking older consumers.
WHAT RULE TO FOLLOW
Adding optional fields is safe; removing or repurposing is not.
