Protobuf messages

In the following sections are described the built in protobuf messages supported by NAIS.

Command

message Command {
  required int32 id = 1;
  optional int32 seq = 2;
  repeated string svals = 3;
  repeated int32 ivals = 4;
}

A Command is a message that performs some action on the board.

id specifies the command.

There could be some predefined commands implemented with a default behaviour, for example the cc3200 board implements (item number is the command id):

1. REBOOT
2. TOGGLE_WIFI_MODE
3. FACTORY_RESET
4. OTA
5. GET_CONFIG

The id values in the set [1,5] are reserved (for cc3200 board) to these default commands: a custom command may use a id starting from 6.

seq is a sequence number garanteed to be unique for each command message not yet acknowledged (see below).

A command returns an acknowldgement message reporting the execution status.

message Ack {
  required int32 id = 1;
  optional int32 seq = 2;
  optional int32 status = 3;
}

The pair (id, seq) identifies a command instance and it is neeeded for matching an Ack message with the correspondig Command message.

status values are used defined but the suggested rule is to set status to 0 for a success command and all other values for error reporting or abnormal execution.

Event

An Event is a message originating by an endpoint, typically a board.

id identifies the event type, for example a Fire Alarm has id==10 and a Movement Detection event has id==12.

svals, fvals and ivals are optional fields used for conveying specific informations related to the event.

message Event {
    required int32  id = 1;
    repeated string svals = 2;
    repeated float  fvals = 3;
    repeated sint32 ivals = 4;
}

Profile

message Profile {
    required string uid = 1;
    required string pwd  = 2;
}

A Profile message embeds a user id and password.

Secret

message Secret {
    required string key = 1;
}

A Secret is a message that can be used to transfer a super secret value.

Config

message Config {
    required string network = 1;
    required string board   = 2;
    required string host = 3;
    optional int32  port = 4;
    optional int32  alive_period = 5;
    optional bool   secure = 6;
}

Config message is used for communicates a well-know identity and network configuration parameters to a board/endpoint.

The pair (board, network) is a unique identifier.

When the board/endpoint support mqtt and the mqtt client is enabled:

• network/board is the subscribe topic
• hb/network/board is the publish topic

host is the dns or ip address of a tcp server or a mqtt broker.

port is the mqtt broker/server remote tcp port.

alive_period is specific to mqtt protocol and it is the time interval between PINGREQ packets.

secure define the type of connection, plain or encrypted.