EQ UART Base Protocol¶
Protocol Overview¶
Functional Scope and Purpose
This document specifies the base protocol for EQ parameter configuration and control between PC-side tools (such as EQ Designer) and the device over UART serial: serial parameters, frame format and byte order conventions.
The specific EQ and tone control commands (0x40-0x5E, 31 commands = 15 active + 16 disabled with code points reserved): see EQ and Tone Control Commands, which correspond one-to-one with the USB HID channel commands (HID code = UART code + 0x4A; band count commands 0x5D/0x5E map to HID 0xB3/0xB4, which do not follow that mapping). For the USB HID channel packet format, see USB HID Base Protocol.
Byte Order Difference from the XU316 UART Base Protocol
This protocol and the XU316↔MCU UART Base Protocol use the same frame header (0x55 0xAA) and frame structure, but with different byte order: this protocol is little-endian, while the XU316↔MCU protocol is big-endian. Do not mix them on the same serial line; refer to the corresponding protocol document.
1. Protocol Foundation Specification¶
1.1 Underlying Communication Protocol¶
EQ Designer uses the serial protocol for communication between the host and the device. The protocol is based on the XU316 zero-code protocol specification and supports EQ parameter settings, reading, mode switching, and other functions.
The two communication roles in this protocol: Host = the party sending EQ control commands (e.g., the PC-side EQ Designer tool or an MCU); Device = XU316 (runs EQ processing, parses commands and returns responses).
| Parameter | Value |
|---|---|
| Baud Rate | 115200 bps |
| Data Bits | 8 |
| Parity | None |
| Stop Bits | 1 |
| Flow Control | None |
1.2 Frame Format and Data Transmission¶
General Frame Format All commands and responses follow this frame format:
| Field | Byte Count | Description |
|---|---|---|
| Frame Header | 2 | Fixed as 0x55 0xAA |
| Version | 1 | Protocol version number (typically 0x00) |
| Command | 1 | EQ Command Code (0x40-0x5E) |
| Data Length | 1 | Length N of subsequent data |
| Data | N | Specific data content |
| Checksum | 1 | Sum of all bytes starting from frame header, modulo 256 (Sum % 256) |
Data Packet Field Example
Byte Pos | Length | Content | Description
---------|--------|---------|------
0 | 1 | 0x55 | Header 1
1 | 1 | 0xAA | Header 2
2 | 1 | Version | Protocol Version (0x00)
3 | 1 | Command | EQ Command Code (0x40-0x5E)
4 | 1 | Length | Data Length
5-N | N | Data | Command Data
N+1 | 1 | Checksum| Checksum
Data Transmission Notes
- Byte Order: All multi-byte data is transmitted in Little Endian mode (Note: Different from XU316 standard protocol's big endian, please refer to this protocol).
- Floating Point: Follows IEEE 754 float format.