An advertising packet is only sent by the slave device and is akin to a simultaneous 'hello' message and invitation for an incoming connection. There are 4 types of advertising packets:
- Give data and allow no incoming connection - used to broadcast small blocks of data.
- Give data and only allow a peer to request one more packet of data
- Give data and invite connection from a specific address (i.e. a bonded/trusted relationship)
- Give data and invite connection from anyone - promiscuous usage
Although a slave can only be connected to one master, it is allowed to advertise types (1) and (2) while in a connection.
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