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PhatenIoT-yan e469ee0144 update

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title	description	keywords
XMOS EQ UART Control Protocol and Command Set	UART serial communication protocol specification for EQ parameter configuration and control, covering frame format, command set, and field descriptions, applicable to XU316 and related products.	EQ, UART, Serial Protocol, Communication Protocol, Command Set, XU316, Zero-Code Firmware, Phaten Audio

XMOS EQ UART Control Protocol and Command Set

--8<-- "common/phaten_xmos_support_img.md"

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.

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 (0x40-0x5C)
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 (0x40-0x5C)
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.

2. Protocol Command Set

2.1 Command Classification Overview

Command	Command Description	Direction	Function
0x40	SET_EQ_MODE	Host→Device	Switch EQ mode
0x41	GET_EQ_MODE	Host→Device	Get current EQ mode information
0x42	SET_MODE_GAIN_AND_NAME	Host→Device	Set mode overall gain and name
0x43	SET_EQ_PARAMS	Host→Device	Send EQ parameters
0x44	GET_EQ_PARAMS	Host→Device	Read EQ parameters
0x45	GET_DEVICE_INFO	Host→Device	Get device information
0x46	RESET_EQ_PARAMS	Host→Device	Reset EQ parameters
0x47	GET_EQ_MODE_COUNT	Host→Device	Get total EQ mode count
0x48	SET_AND_SAVE_EQ_MODE	Host→Device	Set and save EQ mode
0x49	SET_VOLUME	Host→Device	Set volume level
0x4A	GET_VOLUME	Host→Device	Get volume level
0x4B	GET_LED_INFO	Host→Device	Get LED information
0x4C	SET_LED_SWITCH	Host→Device	Set LED switch
0x4D	GET_LED_SWITCH	Host→Device	Get LED switch
0x4E	GET_LED_STATUS	Host→Device	Get LED status
0x4F	GET_LED_COUNT	Host→Device	Get total LED count
0x50	GET_UAC_MODE_INFO	Host→Device	Get UAC mode information
0x51	SET_UAC_MODE	Host→Device	Set UAC mode
0x52	GET_CURRENT_UAC_MODE	Host→Device	Get current UAC mode
0x53	SET_EQ_ENABLE	Host→Device	Set EQ enable switch
0x54	GET_EQ_ENABLE	Host→Device	Get EQ enable switch
0x55	GET_SAMPLE_FORMAT	Host→Device	Get sample rate and format
0x56	SET_GAIN_MODE	Host→Device	Set gain mode
0x57	GET_GAIN_MODE	Host→Device	Get gain mode
0x58	SET_FILTER_MODE	Host→Device	Set filter mode
0x59	GET_FILTER_MODE	Host→Device	Get filter mode
0x5A	SET_GAME_MODE	Host→Device	Set game mode
0x5B	GET_GAME_MODE	Host→Device	Get game mode
0x5C	GET_FIRMWARE_VERSION	Host→Device	Get firmware version

3. Basic Function Command Details

3.1 0x40 - SET_EQ_MODE (Switch EQ Mode)

Function: Switch current EQ mode
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x40    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Mode Value (0-6: Presets, 7-9: User)
6        | 1      | Checksum| Checksum

Device Processing:

Directly sets g_current_eq_mode = data[5]
Does not involve parameter transmission or calculation

3.2 0x41 - GET_EQ_MODE (Get EQ Mode Information)

Function: Read EQ mode information
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x41    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Mode Value (0-9: Valid mode, 0xFF: Get current info)
6        | 1      | Checksum| Checksum

Device Processing:

If mode is 0xFF, returns current mode value, overall gain, and mode name.
If mode is a valid value (0-9), returns specified mode value, overall gain, and mode name.

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x41    | Command Code
4        | 1      | 0x15    | Data Length (21 bytes)
5        | 1      | uint8   | Mode Value (Current or specified)
6-9      | 4      | int32   | Gain Value (Range 0 to -50dB, signed integer)
10-25    | 16     | char    | Mode Name (UTF-8 encoded, 16 bytes)
26       | 1      | Checksum| Checksum

Usage Notes:

When sending mode=0xFF, returns information for the currently active EQ mode.
When sending mode=0-9, returns gain and name information for the specified mode (does not switch current mode).

3.3 0x42 - SET_MODE_GAIN_AND_NAME (Set Mode Overall Gain and Name)

Function: Set EQ mode overall gain and name
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x42    | Command Code
4        | 1      | 0x15    | Data Length (21 bytes)
5        | 1      | uint8   | Mode Value (0-9)
6-9      | 4      | int32   | Gain Value (Range 0 to -50dB, signed integer)
10-25    | 16     | char    | Mode Name (UTF-8 encoded, 16 bytes)
26       | 1      | Checksum| Checksum

Device Processing:

Parses mode value, gain value, and mode name.
Sets the specified mode's EQ overall gain and name for all sample rates' left and right channels.
Supports all sample rates: 44100, 48000, 88200, 96000, 176400, 192000 Hz.

3.4 0x43 - SET_EQ_PARAMS (Send EQ Parameters)

Function: Send parameters for a single filter
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x43    | Command Code
4        | 1      | 0x13    | Data Length (19 bytes: 1 mode + 1 index + 1 type + 4 floats totaling 16 bytes)
5        | 1      | uint8   | Mode Value (0-9)
6        | 1      | uint8   | Filter Band Index (0-7)
7        | 1      | uint8   | Filter Type
8-11     | 4      | float   | Center Frequency (Hz)
12-15    | 4      | float   | Q Value
16-19    | 4      | float   | Bandwidth (Hz)
20-23    | 4      | float   | Gain (dB)
24       | 1      | Checksum| Checksum

Filter Type Codes:

Code	Filter Type
0x00	Bypass Filter
0x01	All Pass Filter
0x02	Peak Filter
0x03	Low Pass Filter
0x04	High Pass Filter
0x05	Band Pass Filter
0x06	Band Reject Filter
0x07	Notch Filter
0x08	Constant Q Filter
0x09	Low Shelf Filter
0x0A	High Shelf Filter

Device Processing:

Parses parameters and stores them into the corresponding mode for all sample rates.
Calls eq_calculate_coefficients_from_params() to calculate coefficients.
Stores calculated coefficients into the corresponding mode for all sample rates.
Automatically applies to all sample rates: 44100, 48000, 88200, 96000, 176400, 192000 Hz.

3.5 0x44 - GET_EQ_PARAMS (Read EQ Parameters)

Function: Read parameters of a single filter
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x44    | Command Code
4        | 1      | 0x02    | Data Length
5        | 1      | uint8   | Mode Value (0-9)
6        | 1      | uint8   | EQ Index (0-7)
7        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x44    | Command Code
4        | 1      | 0x13    | Data Length (19 bytes: 1 mode + 1 index + 1 type + 4 floats totaling 16 bytes)
5        | 1      | uint8   | Mode Value (0-9)
6        | 1      | uint8   | Filter Band Index (0-7)
7        | 1      | uint8   | Filter Type
8-11     | 4      | float   | Center Frequency (Hz)
12-15    | 4      | float   | Q Value
16-19    | 4      | float   | Bandwidth (Hz)
20-23    | 4      | float   | Gain (dB)
24       | 1      | Checksum| Checksum

3.6 0x45 - GET_DEVICE_INFO (Get Device Information)

Function: Get device basic information
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x45    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x45    | Command Code
4        | 1      | 0x34    | Data Length (52 bytes: 2 PID + 2 VID + 16 Product + 16 Vendor + 16 SN)
5-6      | 2      | uint16  | Product ID (PID, Little Endian)
7-8      | 2      | uint16  | Vendor ID (VID, Little Endian)
9-24     | 16     | char    | Product String (UTF-8, 16 bytes)
25-40    | 16     | char    | Vendor String (UTF-8, 16 bytes)
41-56    | 16     | char    | Serial Number String (UTF-8, 16 bytes)
57       | 1      | Checksum| Checksum

3.7 0x46 - RESET_EQ_PARAMS (Reset EQ Parameters)

Function: Delete customer-customized EQ parameters and restore preset parameters
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x46    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Mode Number (0-9, 0xFF means restore all including EQ params, overall gain, mode name)
6        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x46    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Status Code (0x00=Success, 0x01=Failure)
6        | 1      | Checksum| Checksum

Device Processing:

Deletes the EQ parameter file stored in Flash for the specified mode.
Deletes the gain and mode name Flash storage file.
Restores the header file preset parameters for that mode.
If mode number is 0xFF, resets all modes.
Returns operation status.

3.8 0x47 - GET_EQ_MODE_COUNT (Get Total EQ Mode Count)

Function: Get the total number of predefined plus user modes (excluding disabled modes)
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x47    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x57    | Command Code (Note: Matches Chinese doc which says 0x57 here, likely typo in doc but preserving)
4        | 1      | 0x02    | Data Length (2 bytes)
5        | 1      | uint8   | Total Modes (Currently 10, containing 0-9 total 10 modes)
6        | 1      | uint8   | Predefined Mode Count (Currently 7, containing 0-6 total 7 preset modes)
7        | 1      | Checksum| Checksum

3.9 0x48 - SET_AND_SAVE_EQ_MODE (Set and Save EQ Mode)

Function: Set current EQ mode and save to Flash, automatically restore on power-on
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x48    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Mode Value (0-9: 0-6 presets, 7-9 user modes)
6        | 1      | Checksum| Checksum

Device Processing:

Saves mode value to Flash.
Automatically reads and restores this mode from Flash on power-on.

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x48    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Status Code (0x00=Success, 0x01=Failure)
6        | 1      | Checksum| Checksum

3.10 0x49 - SET_VOLUME (Set Volume Level)

Function: Set device volume level
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x49    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Volume Level (0-60: 0=Min, 60=Max)
6        | 1      | Checksum| Checksum

Parameter Description:

Volume Level Range: 0-60 (Total 61 levels)
Description: Controls device output volume level
- 0: Minimum Volume (approx -127.5dB)
- 60: Maximum Volume (0dB)
- Approximately 2dB attenuation change per level

Device Processing:

Parameter will be automatically saved to Flash via existing periodic save mechanism.
If parameter exceeds range (>60), firmware will reject setting and return false.

3.11 0x4A - GET_VOLUME (Get Volume Level)

Function: Read device current volume level
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4A    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4A    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Current Volume Level (0-60)
6        | 1      | Checksum| Checksum

3.12 0x4B - GET_LED_INFO (Get LED Information)

Function: Read LED index and LED name
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4B    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | LED Index (0-7, current device only has 1 LED, index 0)
6        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4B    | Command Code
4        | 1      | 0x11    | Data Length (17 bytes)
5        | 1      | uint8   | LED Index (0-7)
6-21     | 16     | char    | LED Name (UTF-8 encoded, 16 bytes)
22       | 1      | Checksum| Checksum

3.13 0x4C - SET_LED_SWITCH (Set LED Switch)

Function: Set LED switch state
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4C    | Command Code
4        | 1      | 0x02    | Data Length
5        | 1      | uint8   | LED Index (0-7, current device only has 1 LED, index 0)
6        | 1      | uint8   | LED Switch (0=OFF, 1=ON)
7        | 1      | Checksum| Checksum

Device Processing:

When LED switch is OFF, all LED outputs are disabled, no LED is displayed.
When LED switch is ON, LED displays normally.

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4C    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Status Code (0x00=Success, 0x01=Failure)
6        | 1      | Checksum| Checksum

3.14 0x4D - GET_LED_SWITCH (Get LED Switch)

Function: Read LED switch state
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4D    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | LED Index (0-7, current device only has 1 LED, index 0)
6        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4D    | Command Code
4        | 1      | 0x02    | Data Length
5        | 1      | uint8   | LED Index (0-7)
6        | 1      | uint8   | LED Switch (0=OFF, 1=ON)
7        | 1      | Checksum| Checksum

3.15 0x4E - GET_LED_STATUS (Get LED Status)

Function: Read LED RGB color and status
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4E    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | LED Index (0-7, current device only has 1 LED, index 0)
6        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4E    | Command Code
4        | 1      | 0x05    | Data Length
5        | 1      | uint8   | LED Index (0-7)
6        | 1      | uint8   | R Color Value (0-255)
7        | 1      | uint8   | G Color Value (0-255)
8        | 1      | uint8   | B Color Value (0-255)
9        | 1      | uint8   | LED Status (0=Off, 1=Solid, 2=Slow Blink, 3=Fast Blink, 4=Breathe)
10       | 1      | Checksum| Checksum

LED Status Enum:

0: LED_STATUS_OFF (Off)
1: LED_STATUS_SOLID (Solid On)
2: LED_STATUS_SLOW_BLINK (Slow Blink)
3: LED_STATUS_FAST_BLINK (Fast Blink)
4: LED_STATUS_BREATHE (Breathe)

Note:

RGB color values are converted based on current LED color definition (active low).
LED status is determined based on current LED display mode (solid/blink).

3.16 0x4F - GET_LED_COUNT (Get LED Count)

Function: Read total number of LEDs supported by device
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4F    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x4F    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Total LEDs (Current device is 1)
6        | 1      | Checksum| Checksum

Device Processing:

Returns total number of LEDs supported by device.
Current device only has 1 LED, so returns 1.
LED index range is 0 to (Total LEDs - 1).

3.17 0x50 - GET_UAC_MODE_INFO (Get UAC Mode Information)

Function: Read UAC mode count and mode name list
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x50    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x50    | Command Code
4        | 1      | 0x11    | Data Length (17 bytes)
5        | 1      | uint8   | Total UAC Modes (Currently 2, containing UAC1.0 and UAC2.0)
6-13     | 8      | char    | Mode 0 Name (UTF-8, 8 bytes, e.g., "UAC2.0")
14-21    | 8      | char    | Mode 1 Name (UTF-8, 8 bytes, e.g., "UAC1.0")
22       | 1      | Checksum| Checksum

Device Processing:

Returns total UAC modes (currently 2).
Returns name for each mode (max 8 chars).
Mode 0 corresponds to UAC2.0, Mode 1 corresponds to UAC1.0.

3.18 0x51 - SET_UAC_MODE (Set UAC Mode)

Function: Set UAC mode (UAC1.0 or UAC2.0)
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x51    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | UAC Mode Value (0=UAC2.0, 1=UAC1.0)
6        | 1      | Checksum| Checksum

Device Processing:

Sets UAC mode and reboots device.
Note: Device will not return a response after reboot.

3.19 0x52 - GET_CURRENT_UAC_MODE (Get Current UAC Mode)

Function: Read current UAC mode
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x52    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x52    | Command Code
4        | 1      | 0x09    | Data Length (9 bytes)
5        | 1      | uint8   | Current UAC Mode Value (0=UAC2.0, 1=UAC1.0)
6-13     | 8      | char    | Current UAC Mode Name (UTF-8, 8 bytes, e.g., "UAC2.0" or "UAC1.0")
14       | 1      | Checksum| Checksum

Device Processing:

Returns current UAC mode name (max 8 chars).

3.20 0x53 - SET_EQ_ENABLE (Set EQ Enable Switch)

Function: Set EQ enable switch (Enable/Disable)
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x53    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | EQ Enable Switch (0=OFF Disable, 1=ON Enable)
6        | 1      | Checksum| Checksum

Device Processing:

Only saves EQ enable status to Flash (independent file storage), does not affect saved modes.

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x53    | Command Code
4        | 1      | 0x02    | Data Length
5        | 1      | uint8   | Status Code (0x00=Success, 0x01=Failure)
6        | 1      | uint8   | Current EQ Enable Status (0=OFF, 1=ON)
7        | 1      | Checksum| Checksum

3.21 0x54 - GET_EQ_ENABLE (Get EQ Enable Switch)

Function: Read EQ enable switch status
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x54    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x54    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | EQ Enable Switch Status (0=OFF Disable, 1=ON Enable)
6        | 1      | Checksum| Checksum

Device Processing:

Returns current EQ enable switch status (0=OFF, 1=ON).

3.22 0x55 - GET_SAMPLE_FORMAT (Get Sample Rate and Format)

Function: Read current sample rate and DSD mode
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x55    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x55    | Command Code
4        | 1      | 0x05    | Data Length (5 bytes)
5-8      | 4      | uint32  | Sample Rate (samFreq, Little Endian, Unit: Hz)
9        | 1      | uint8   | DSD Mode (dsdMode: 0=PCM, 1=DOP, 2=Native DSD)
10       | 1      | Checksum| Checksum

Device Processing:

Returns current sample rate (32-bit unsigned integer, Little Endian, Unit: Hz).
Returns DSD mode (0 means PCM format, >0 means DSD format).
Device will automatically report this information when sample rate or DSD mode changes (proactively sent via UART).

Auto-Report Mechanism:

Device monitors sample rate and DSD mode changes.
When these values change, device automatically constructs 0x55 response packet and sends via UART.

3.23 0x56 - SET_GAIN_MODE (Set Gain Mode)

Function: Set gain mode
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x56    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Gain Mode Value (0=Low Impedance, 1=High Impedance)
6        | 1      | Checksum| Checksum

Parameter Description:

Gain Mode Range: 0-1
Description: Controls device gain level
- 0: Low Impedance Mode (Suitable for high sensitivity headphones)
- 1: High Impedance Mode (Suitable for high impedance headphones)

Device Processing:

Parameter will be automatically saved to Flash via existing periodic save mechanism.

3.24 0x57 - GET_GAIN_MODE (Get Gain Mode)

Function: Read device current gain mode
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x57    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x57    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Current Gain Mode (0=Low Impedance, 1=High Impedance)
6        | 1      | Checksum| Checksum

3.25 0x58 - SET_FILTER_MODE (Set Filter Mode)

Function: Set filter mode
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x58    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Filter Mode Value (0-7: 8 filter modes)
6        | 1      | Checksum| Checksum

Parameter Description:

Filter Mode Range: 0-7 (Total 8 modes)
Description: Select DAC digital filter type
- 0: Minimum Phase filter (default)
- 1: Linear Phase Apodizing Fast Roll-off filter
- 2: Linear phase fast roll-off filter
- 3: Linear Phase Fast Roll-off low-ripple filter
- 4: Linear phase slow roll-off filter
- 5: Minimum phase fast roll-off filter
- 6: Minimum phase slow roll-off filter
- 7: Minimum Phase Fast Roll-Off Low Dispersion

Device Processing:

Parameter will be automatically saved to Flash via existing periodic save mechanism.
If parameter exceeds range (>7), firmware will reject setting and return false.

3.26 0x59 - GET_FILTER_MODE (Get Filter Mode)

Function: Read device current filter mode
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x59    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x59    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Current Filter Mode (0-7)
6        | 1      | Checksum| Checksum

3.27 0x5A - SET_GAME_MODE (Set Game Mode)

Function: Set game mode
Direction: Host→Device
Data Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x5A    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Game Mode Value (0=No effect, 1=FPS, 2=Virtual 7.1)
6        | 1      | Checksum| Checksum

Parameter Description:

Game Mode Range: 0-2
Description: Select game audio effect mode
- 0: No effect (Standard Stereo)
- 1: FPS Mode (Enhanced Positioning)
- 2: Virtual 7.1 (Surround Sound Effect)

Device Processing:

Parameter will be automatically saved to Flash via existing periodic save mechanism.
If parameter exceeds range (>2), firmware will reject setting and return false.

3.28 0x5B - GET_GAME_MODE (Get Game Mode)

Function: Read device current game mode
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x5B    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x5B    | Command Code
4        | 1      | 0x01    | Data Length
5        | 1      | uint8   | Current Game Mode (0=No effect, 1=FPS, 2=Virtual 7.1)
6        | 1      | Checksum| Checksum

3.29 0x5C - GET_FIRMWARE_VERSION (Get Firmware Version)

Function: Read device firmware version number
Direction: Host→Device
Request Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x5C    | Command Code
4        | 1      | 0x00    | Data Length
5        | 1      | Checksum| Checksum

Response Packet Format:

Byte Pos | Length | Content | Description
---------|--------|---------|------
0        | 1      | 0x55    | Header 1
1        | 1      | 0xAA    | Header 2
2        | 1      | 0x00    | Version
3        | 1      | 0x5C    | Command Code
4        | 1      | 0x03    | Data Length (3 bytes)
5        | 1      | uint8   | Major Version (BCD, e.g., 0x01 means 1)
6        | 1      | uint8   | Minor Version (BCD, e.g., 0x00 means 0)
7        | 1      | uint8   | Revision Version (BCD, e.g., 0x0C means 12)
8        | 1      | Checksum| Checksum

Version Number Format:

Version number uses BCD (Binary Coded Decimal) format.
3 bytes represent: Major Version, Minor Version, Revision Version.
Example: 0x01 0x00 0x0C means version 1.0.12.

4. Key Features

4.1 Device-Side Coefficient Calculation

Host only sends parameters (fc, Q, bw, gain).
Device calculates filter coefficients in real-time based on parameters.
Supports dynamic bshift calculation to ensure coefficient precision.

4.2 Parameter Format

Floating Point Parameters: fc, Q, bw, gain use IEEE 754 float format transmission.
Byte Order: All multi-byte data uses Little Endian.

4.3 Error Handling

Data packet length check.
Frame header verification.
Parameter range check.
Filter index boundary check.

4.4 Mode Management

Supports 10 EQ modes (0-9: 0-6 presets, 7-9 user modes)
Automatically clears filter state when switching modes.

5. Notes

Timing Requirements: After sending parameters, wait for device processing to complete before sending the next command.
Data Integrity: All 8 filter parameters need to be sent, even if some filters are unused.
Mode Synchronization: After setting mode, call read mode to ensure data synchronization.
Error Recovery: Re-establish connection and retry upon communication failure.
Parameter Validation: Device verifies parameter range, values out of range will be limited.
Checksum Calculation: All commands must include correct checksum, which is the sum of all bytes from frame header to end of data, modulo 256.

Consultation and Feedback

Click to expand consultation and feedback form

--8<-- "common/customer_form.md"

38 KiB Raw Blame History

XMOS EQ UART Control Protocol and Command Set

1. Protocol Foundation Specification

1.1 Underlying Communication Protocol

1.2 Frame Format and Data Transmission

2. Protocol Command Set

2.1 Command Classification Overview

3. Basic Function Command Details

3.1 0x40 - SET_EQ_MODE (Switch EQ Mode)

3.2 0x41 - GET_EQ_MODE (Get EQ Mode Information)

3.3 0x42 - SET_MODE_GAIN_AND_NAME (Set Mode Overall Gain and Name)

3.4 0x43 - SET_EQ_PARAMS (Send EQ Parameters)

3.5 0x44 - GET_EQ_PARAMS (Read EQ Parameters)

3.6 0x45 - GET_DEVICE_INFO (Get Device Information)

3.7 0x46 - RESET_EQ_PARAMS (Reset EQ Parameters)

3.8 0x47 - GET_EQ_MODE_COUNT (Get Total EQ Mode Count)

3.9 0x48 - SET_AND_SAVE_EQ_MODE (Set and Save EQ Mode)

3.10 0x49 - SET_VOLUME (Set Volume Level)

3.11 0x4A - GET_VOLUME (Get Volume Level)

3.12 0x4B - GET_LED_INFO (Get LED Information)

3.13 0x4C - SET_LED_SWITCH (Set LED Switch)

3.14 0x4D - GET_LED_SWITCH (Get LED Switch)

3.15 0x4E - GET_LED_STATUS (Get LED Status)

3.16 0x4F - GET_LED_COUNT (Get LED Count)

3.17 0x50 - GET_UAC_MODE_INFO (Get UAC Mode Information)

3.18 0x51 - SET_UAC_MODE (Set UAC Mode)

3.19 0x52 - GET_CURRENT_UAC_MODE (Get Current UAC Mode)

3.20 0x53 - SET_EQ_ENABLE (Set EQ Enable Switch)

3.21 0x54 - GET_EQ_ENABLE (Get EQ Enable Switch)

3.22 0x55 - GET_SAMPLE_FORMAT (Get Sample Rate and Format)

3.23 0x56 - SET_GAIN_MODE (Set Gain Mode)

3.24 0x57 - GET_GAIN_MODE (Get Gain Mode)

3.25 0x58 - SET_FILTER_MODE (Set Filter Mode)

3.26 0x59 - GET_FILTER_MODE (Get Filter Mode)

3.27 0x5A - SET_GAME_MODE (Set Game Mode)

3.28 0x5B - GET_GAME_MODE (Get Game Mode)

3.29 0x5C - GET_FIRMWARE_VERSION (Get Firmware Version)

4. Key Features

4.1 Device-Side Coefficient Calculation

4.2 Parameter Format

4.3 Error Handling

4.4 Mode Management

5. Notes

Consultation and Feedback

38 KiB

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