Ublox SARA-G450 Series - Firmware Upgrade, Last Gasp, and Power Saving

SARA-G450 - System integration manual
UBX-18046432 - R08 System description Page 54 of 143
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1.13.12 Firmware upgrade Over AT (FOAT)
1.13.12.1 Overview
This feature allows upgrading the module’s firmware over the AT interface of the module, using AT
commands.
 The +UFWUPD AT command triggers a reboot followed by the upgrade procedure at a specified
baud rate (see the u-blox AT commands manual [11] for more details).
 A special boot loader on the module performs firmware installation, security verifications and
module reboot.
 Firmware authenticity verification is performed via a security signature during the download. The
firmware is then installed, overwriting the current version. In the event of power loss during this
phase, the boot loader detects a fault at the next wake-up, and restarts the firmware download
from the Xmodem-1k handshake. After completing the upgrade, the module is reset again and
wakes up in normal boot.
1.13.12.2 FOAT procedure
The application processor must proceed in the following way:
 Send the +UFWUPD AT command through the AT interface, specifying file type and desired baud
rate
 Reconfigure serial communication at selected baud rate, with the used protocol
 Send the new FW image via the used protocol
⚠ After FW image is sent, module reboots and can stay unresponsive up to 2 minutes with V_INT
low; it is strongly recommended not to remove VCC during this step.
☞ It is suggested to check if enough space is available in module’s file system before the FOAT
procedure.
☞ After upgrade with FOAT procedure, it is necessary to restore factory configuration by mean of
AT+UFACTORY=1,1 command in order to restore the complete file system space.
1.13.13 Last gasp
☞ Not supported by the “00” product version.
In the event of a power supply outage (i.e. main supply interruption, battery removal, battery voltage
below a certain threshold), the cellular module can be configured to send an alarm notification to a
remote entity after a trigger by a GPIO pin properly configured. The alarm notification can be set with
an AT command.
For the detailed description, see section 1.11 and the u-blox AT commands manual [11], +ULGASP AT
command.