Concepts

Libelium OTA has been designed to work exclusively over the Waspmote platform.

Waspmote is a sensor device oriented to Internet of Things. It works with different protocols such as: 802.15.4, ZigBee, WiFi, 4G/GPRS, etc.

It counts with sleep modes which allow to save battery when it is not transmitting. Besides, there are more than 90 sensors available and a complete open source IDE (API libraries + compiler) which make it really easy to start working with the platform.

Note: to run programs which make use of the hibernate mode, it is needed to set the hibernate switch off, so this feature cannot be used with OTA. However, sleep or deepsleep modes can be performed.

Figure : Waspmote Sensorial Device

The Waspmote IDE v05 generates the binary file to be used in OTA programmings. There is a specific option in the Waspmote IDE that permits to generate the necessary binary file for OTA in: "Sketch" → "Export binary to OTA file". When this option is chosen, the program is compiled and two files are generated inside /sketchbook/OTA-FILES folder: a hexadecimal and a binary file. The second one is valid for OTA via FTP with 4G/3G/GPRS/WiFi modules.

STEP 1: Click "Sketch" → "Export binary to OTA file" to generate the binary file:

Figure: Waspmote IDE generates binary files

STEP 2: Search the binary file in the correct folder:

Figure: OTA-FILES folder

For instance, we are managing a program called _4G_20_OTA.pde. When the binary files are exported, two files are created inside the sketchbook sub-folder called OTA-FILES:

• _4G_20_.hex is the program compiled

• _4G_20_ is the binary file needed for OTA via 4G (always defined by seven characters)

The Waspmote IDE gives these filenames truncating to seven characters the name of the Waspmote program.

NOTE: It is important to remark that the filename given by the Waspmote IDE to the binary files CAN NOT be changed. Otherwise, OTA will not work.

OTA via FTP

The reprogramming process is initiated by Waspmote and it is supported by an FTP server.

Steps:

• Waspmote queries the FTP server for a new program version

• Check if program name, path and version are correct

• Download the new program

• Reboot and start with the new program

Topologies:

• Protocols which support FTP transmissions are directly connected to

  the Network Access Point

Protocols supported:

• 4G modules:

  • LE910 EUG: 4G bands (800/1800/2600), 3G bands (850/900/2100), 2G bands (900/1800)

  • LE910 NAG: 4G bands (700/850/1700/1900), 3G bands (850/1900), 2G bands (850/1900)

  • LE910 AU: 4G bands (700/1800/2600)

• 3G - Tri-Band (2100/1900/900 MHz), Quad-Band (850/900/1800/1900 MHz)

• GPRS - 850/900/1800/1900 MHz

• WiFi - 2.4 GHz (Worldwide)

Storage System:

Once the program is downloaded to Waspmote it is stored it in the 2 GB SD card.

Meshlium OTA-FTP plug-in

Meshlium provides both FTP server and Manager System plug-in which permit to configure the server automatically by attaching the program binary file to be used.