Protobuf notes

Protobuf references, somewhat arbitrary starting point yet introduces some key topics of Protobuf standard and use cases:

• https://www.crankuptheamps.com/blog/posts/2017/10/12/protobuf-battle-of-the-syntaxes/
• https://www.educative.io/edpresso/what-is-the-difference-between-protocol-buffers-and-json

• https://developers.google.com/protocol-buffers/docs/proto
• https://spline.de/talks/protobuf.pdf

JSON supported data types:

• https://www.w3schools.com/js/js_json_datatypes.asp

First Protobuf .proto file, compiles using `protoc-c`, part of a package available with Ubuntu 20.04:

// syntax = "proto3";
syntax = "proto2";

// Notes:
// $ protoc-c --c_out=. ./first.proto

message sensorUpdates {
  required int32 message_id = 1;
  optional float vrms = 2;
}

. . . It appears that the integer values which message elements are assigned as tantamount to key names in JSON.