Research and Design of Distributed Fire Alarm System of Indoor Internet of Things Based on LoRa

Table 2

Protocol frame format table.

Frame content	Occupied bytes	Parameter range	Remark
Frame header	1		Corresponding character “@”
Target node ID	2	0x0000 − 0xffff	0xffff is a broadcast signal, all nodes respond
Configuration mode frame	1	0: flash	0 × 00: Set the wake-up time of nodes and store the parameters in flash
		1: read	0 × 01: Immediately request the node to send current sensor data
Configuration data frame	2	0-65535	Analyze different data according to different configuration mode frames
Reserved byte	10		Reserved for future use
Frame tail	1		Corresponding character “$”