IDEETRON Nexus LoRaWAN, Руководство пользователя

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Nexus LoRaWAN
5 LoRaWAN introduction
The LoRaWAN communication takes place in two directions, up (from Nexus to gateway) and
down (from gateway to Nexus). This sketch can transmit messages in the up direction and receive
messages in the down direction.
Figure 1: LoRaWAN communication
The channel and datarate for the both directions can be set.
Also the class of the Nexus board can be set to type A or C.
A type A mote can only receive messages from the gateway in a specific timeslot after sending a
message.
A type C mote can receive a message from the gateway any time, except when the mote is
transmitting a message.
6 Operation
If the Nexus receives a message it will check if the CRC and MIC is ok and if it is a message for this
device. Then it will be broken down in the different fields. The Nexus will send the following
information using to serial communication:
Message Value Description
CRC OK/NOK If the CRC of the received
radio message is ok.
MIC OK/NOK If the MIC calculation of the
LoRaWAN package is ok.
Address OK/NOK If the package contains the
address for this mote
MAC Header See Table 5 LoRaWAN MAC header
Sensor 4 bytes in Hex Device address
Frame counter 2 bytes in Hex Number of frame
Frame control 00 or 20 LoRaWAN Fctrl field
Data Bytes in Hex Data send from mote or
gateway
Table 3: Message information
The MAC Header specifies the message type and the version of the LoRaWAN protocol used.
Bits 7 – 5 4 – 2 1 – 0
Field Message type Reserved LoRaWAN protocol
Table 4: MAC Header fields
The LoRaWAN protocol field will always be 00.
The reserved field bits will always be 0.