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v6.3
Over the Air Programming (OTA)
21.3. Concepts
There are two different OTA methodologies:
•
OTA with 802.15.4/ZigBee modules
•
OTA with 3G/GPRS/WiFi modules via FTP
21.3.1. OTA with 802.15.4/ZigBee modules
The idea is simple. When the programmer (normally the Gateway) sends a new program it is stored in the SD card. A second
command “start_new_program” is needed in order to make them start. Then, the nodes copy the program from the SD card to
the Flash memory and start the new program.
Steps:
•
Locate the node to upgrade
•
Check current software version
•
Send the new program
•
Reboot and start with the new program
•
Restore the previous program if the process fails
OTA modes:
•
Unicast: Reprogram an specific node
•
Multicast: Reprogram several nodes at the same time sending the program just once
•
Broadcast: Reprogram the entire network sending the program just once
Topologies:
•
Direct access: when the nodes are accessed in just one hop (no forwarding of the packets is needed)
•
Multihop: when the nodes are accessed in two or more hops. In this mode some nodes have to forward the packets sent
by the Gateway in order to reach the destination
Protocols supported:
•
802.15.4 - 2.4GHz (Worldwide)
•
ZigBee - 2.4GHz (Worldwide).
Important:
OTA operations only available from the Gateway, not from Meshlium.
•
DigiMesh - 2.4GHz (Worldwide)
•
RF - 868MHz (Europe)
•
RF - 900MHz (US, Canada, Australia)
Storage System:
Once we have sent the program to Waspmote it will store it in the internal memory, a 2GB SD card.
If we have into account that the maximum size for a program is 128KB, this means we can store thousands different firmware
versions inside each node.
Encryption and Authentication:
All the data which is sent in the OTA process can be secured by activating the encryption algorithm AES 128b which works in
the link layer. As well as this, a second pass key is needed to be known by the OTA programmer (the Gateway) in order to be
authenticated and validated by each node before starting with the OTA action requested.
Содержание Waspmote
Страница 1: ...Waspmote Technical Guide ...
Страница 11: ... 11 v6 3 Waspmote Kit Connect the battery in Waspmote Connect the sensor board Switch it on ...
Страница 59: ... 59 v6 3 Sensors Vibration Acceleration Free fall ...
Страница 79: ... 79 v6 3 LoRa Figure Channel frequencies in the 868MHz band Figure Channel frequencies in the 900MHz band ...
Страница 98: ... 98 v6 3 RFID NFC ...