Over-The-Air (Ota) Firmware Updates; Distribute The New Application - Digi XLR PRO User Manual

Advanced application features
Flash memory write operations are only capable of changing binary 1s to binary 0s. Only the
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erase operation can change binary 0s to binary 1s. For this reason, you should erase a flash
block before performing a write operation.
When performing an erase operation, you must erase the entire flash memory block—you
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cannot erase parts of a flash memory block.
Flash memory has a limited lifetime. The flash memory on which the GPM is based is rated at
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20,000 erase cycles before failure. Take care to ensure that the frequency of erase/write
operations allows for the desired product lifetime. Digi's warranty does not cover products that
have exceeded the allowed number of erase cycles.
Over-the-air firmware upgrades erase the entire GPM. Any user data stored in the GPM will be
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lost during an over-the-air upgrade.

Over-the-air (OTA) firmware updates

XLR PROs provide two methods of firmware update:
Local firmware update via XCTU using the serial interface.
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Over-the-air firmware update using the RF interface.
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The over-the-air firmware update method provides a robust and versatile technique which can be
tailored to many different networks and applications, with minimum disruption of normal network
operations.
Over-the-air firmware updates can be sent to a remote node using a local node and XCTU, or an
external application can be programmed to follow this process. There are three phases of the over-
the-air update process: distributing the new application, verifying the new application, and installing
the new application. In the following section, the node to be updated is referred to as the target node.
The node providing the update information is referred to as the source node. In most applications, the
source node is locally attached to a PC running update software.

Distribute the new application

The first phase of performing an over-the-air update on a device is transferring the new firmware file
to the target node. Load the new firmware image in the target node's GPM prior to installation. XLR
PRO RF Modules use an encrypted binary (.ebin) file for both serial and over-the-air firmware updates.
These firmware files are available on the
Send the contents of the .ebin file to the target device using general purpose memory WRITE
commands. Erase the entire GPM prior to beginning an upload of an .ebin file. The contents of the .ebin
file should be stored in order in the appropriate GPM memory blocks. The number of bytes that are
sent in an individual GPM WRITE frame is flexible and can be catered to the user application.
Example
XLR PRO firmware version 1003 has an .ebin file of 1,048,576 bytes in length. Based on using a
recommended packet size of 1024 bytes, sending a packet every 30 seconds minimized network
disruption. For this reason, the .ebin should be divided and addressed as follows:
XLR PRO Radio Frequency (RF) Module User Guide

Over-the-air (OTA) firmware updates

Digi Support website and via XCTU.
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