Public firmware releases for the ZOUDIO AIO438 amplifier:
https://github.com/ZOUDIO/AIO438-firmware-releases/releases
Always use the latest firmware available unless you have been instructed otherwise.

Firmware is in binary format (.hex) and can be uploaded to the board using the ZOUDIO configtool (zoudio.com/configtool)
After connecting to the amp, you can browse for the HEX file using the dropdown menu on the upload button ('upload new firmware').
Uploading unknown binaries to the board voids your warranty

The AIO438 can be connected to a PC via its onboard USB-C port. Normally, the ZOUDIO configtool can be used to communicate with the board. Commands can also be send via a regulator terminal at 38400 baudrate, 8N1 format.

The serial protocol has two sides:

• Human-readable (ASCII) for standard commands
  Simple human-readable, can be used by anyone. See CLI description down below.

• Binary protocol for DSP data transfer
  Complex and not suitable for humans. These commands are used for large data transfer like DSP settings, normally generated by the configtool.

Default state of the board is low power standby.
Sending a command or pressing the volume button wakes it up.
The configtool just sends ECHO commands until the board wakes up and responds.

• (argument) is a user-provided argument with the unit mentioned for the specific command.
• The default response to a command is a non-acknowledge (nAck) message: "nAck: (command)"

For questions contact [email protected]