Before manipulating firmware, you must understand the hardware. The JL381A is a cost-optimized 32-bit microcontroller based on a custom RISC core, produced by JL Ltd (Zhuhai Jieli Technology). It is not an ARM Cortex-M; it uses a proprietary instruction set designed for ultra-low-power audio processing.
Key specifications of the JL381A:
The lack of internal flash is critical: the JL381A firmware lives on an external Winbond, XMC, or Puya SPI flash chip. This design allows manufacturers to upgrade storage without redesigning the PCB but makes firmware corruption more common due to voltage fluctuations on the SPI bus. jl381a firmware
Since the firmware lives on an external SPI flash, you can program it directly using a CH341A, FT2232H, or Raspberry Pi GPIO.
You will need:
Steps:
Timing tip: Set the CH341A speed to “Slow” (under 1 MHz) to avoid bus errors with long wires. The lack of internal flash is critical: the
Aruba splits its firmware releases for the JL381A into two distinct tracks:
Cause: Incorrect firmware (e.g., loading JL381B firmware onto a JL381A) or power loss during flash write. Solution: Steps:
The JL381A is still actively supported. Key branches:
Always check the Aruba Support Portal for the most recent recommended version.
