HL7810 Delta Firmware Update (.ua file) Request + Clarification on Update Methods

IoT Modules
1

Hi Sierra Wireless Team,

We are developing a product using the HL7810 module (currently running firmware HL7810.5.7.4.0) on a custom board with an STM32 MCU. We need to implement firmware updates for the modem and have two questions:

1. Request for HL7810 Delta Firmware (.ua) File

We are implementing the Local Delta Firmware Download method as described in Section 6 of the HL78 Series — Firmware Update Methods application note (Rev 2.2), using AT+WDSD + XMODEM-1K over the AT command UART.

Our current implementation flow:

AT+WDSI=4470          → enable firmware update indications
AT+WDSD=<file_size>   → initiate download mode
XMODEM-1K transfer    → send .ua delta file over UART
AT+WDSR=4             → trigger installation
Wait for +WDSI:16     → success confirmation

We have tested this on the HL7810 EVK and the XMODEM-1K transfer completes successfully (modem returns +WDSI:3 confirming download). However, AT+WDSR=4 returns +CME ERROR: 3 because the only .ua files we have are for HL7800, not HL7810.

Could you provide the correct .ua delta firmware file(s) for the HL7810 with source version 5.7.4.0? (i.e., a file that upgrades FROM 5.7.4.0 to the latest available version), or files that I can use to downgrade the firmware to and then update it.

2. Clarification on Firmware Update Methods from MCU

Our MCU communicates with the HL7810 exclusively via the AT command UART. We initially attempted a full firmware update (U-Boot + Kermit protocol) but after extensive testing on the EVK, we determined that U-Boot’s console is not accessible via the AT command UART — it appears to be routed to USB or a dedicated debug interface.

Could you please confirm:

  • Is the delta update (AT+WDSD + XMODEM-1K) the correct/recommended method for MCU-driven firmware updates over the AT command UART?

  • Is a full firmware update (via U-Boot/Kermit) possible over the AT command UART, or does it require USB/other interface?

  • Are there any limitations on what can be updated via the delta method vs. full update? (e.g., can the delta update the modem firmware, radio firmware, and application firmware, or only certain partitions?)

  • Is there a maximum .ua file size supported by AT+WDSD? The application note mentions ~2.78 MB RAM available for download.

Our production flow will be: STM32 reads .ua file from SD card → sends AT+WDSD → transfers file via XMODEM-1K over UART → triggers install via AT+WDSR=4. We want to confirm this is the supported approach.

Thank you for your help.

2

Have you contacted distributor to request the file?

3

Hi @jyijyi, thanks for the response.

We purchased the HL7810 modules through Digi-Key. Should we contact Digi-Key directly to request the .ua delta firmware files, or is there a separate Semtech/Sierra Wireless distribution channel we should reach out to? We want to make sure we’re requesting through the correct path.

Specifically, we need:

  • XMODEM local delta package for HL7810 (expected naming: XMODEM_HL7810-M.<version>.7z)

  • Delta files with source version 5.7.4.0 (to upgrade from our current firmware)

  • Ideally, delta files for both directions (upgrade and downgrade) so we can validate the full update cycle

Also, while investigating firmware update methods, we did extensive testing on the HL7810 EVK and confirmed the following, could someone from the Sierra team please verify?

Our findings on full firmware update (U-Boot/Kermit method):

  • U-Boot bootloader console is accessible on UART0 (the diagnostic interface, pins C55–C58) as documented in Section 4.11 of the HL781x Product Technical Specification

  • By default, AT+KBOOTCFG has boot_usb_enum=1, which routes U-Boot to USB. Setting AT+KBOOTCFG=0,5,0 routes it to UART0

  • U-Boot is never accessible on UART1 (the AT command port), we tested this extensively

  • This means full firmware updates (via U-Boot + Kermit/SFT) are not possible from a host MCU that only connects to UART1

Our conclusion:
For MCU-driven firmware updates where the host is connected to the AT command UART (UART1) only, the Local Delta method (AT+WDSD + XMODEM-1K) is the only supported approach. Is this correct?

Thank you!

4

Yes, you should contact distributor
Besides, you can also see here:

Will your mcu have uart to connect to linux or windows?
If yes, your mcu can work as middle-man to bypass the data to module from pc?