Hi Vianney,
Hmmm, OTA upgrade wouldn’t be an option for us on our production lines, as it would geographically constrain production to areas of the world where there is HL7692 Cellular network coverage. In any case production line OTA upgrade would take too long and be of variable duration dependant on Cellular network conditions.
The HL7692 itself would seem to support firmware upgrade via UART as well as USB (see +BOOTDWLCFG command within AirPrime_HL76xx_AT_Commands_Interface_Guide_Rev13_0.pdf)
Might it be possible for Sierra to consider revising the HL769x.2.27.183100.201809071813.x7120m_3_signed_exe.exe installer, to support also upgrade via UART ? Perhaps Sierra could use the source code for HL7800.4.3.9.0_EXE as basis, because as mentioned, that supports upgrade via UART as well as USB.
There’s no big hurry to add HL7692 firmware upgrade via UART to the HL769x.2.27.183100.201809071813.x7120m_3_signed_exe.exe installer. But if we know you have that scheduled to be available within say, 2 months, we can plan accordingly.
The design of our daughterboard PCB that uses the HL7692, implements only UART connectivity. Adding in USB connectivity, from daughterboard to motherboard MCU, would be a major upheaval at this stage, and set back the product by several months. We were unaware that HL7692 firmware installer .exe’s were limited to USB.
Best regards,
David