[HL7688] Firmware Update via UART from Embedded Linux (Busybox) — Procedure & Tools?

@jyijyi Thanks, I was able to successfully update the modem firmware using the AT commands. Below are a few observations that were not mentioned in the datasheet, or that I discovered during the process:

  • AT+KSLEEP=0 — Sleep mode must be disabled; otherwise, the file transfer will not work.

  • AT+WDSI=4095 — This enables all notifications.

  • After the file transfer, I did not receive the expected +WDSI: 3. I manually issued AT+WDSR=4 and waited until +WDSI: 16 appeared.

This topic was helpful → HL7688 Firmware Archive

However, I only see the firmware version RHL7688.A.2.15.1.0.151600.201809181425.x71601signed_DWL.dwl available for download(Already my current version). Are there other versions I can test—for example, to perform upgrade/downgrade validation?

The available file is quite large (~20 MB) and takes a long time to transfer over UART. Are delta-update files available instead? If so:

  • Where can I obtain them?

  • How should they be flashed onto the modem?