lark

Control Hollyland Lark wireless mic receivers over USB. Plug in the receiver and run a command; the model is detected automatically.

Model	USB IDs	Status
Lark A1	3547:0407	Tested on hardware
Lark C1, M1, Mini, M2	3547:0001, 000B, 000C, 000D, 0007, 0008; EaglesHero 4417:0020, 0021	Untested
Lark M2S	3547:0405, 0406	Untested
Lark A2	3547:0411, 8775	Untested
Lark M3	3547:040C–040F	Untested
Lark Max 2 (USB receiver)	3547:0402, 0403	Untested

Untested means the protocol was read out of Hollyland's HollyAudio 3.0.6 Android app but has never been run against that device. It may not work at all. If you have one, run node lark.js status and open an issue with what you see. See Untested models for details.

The MELO P1 isn't supported. It's a mixer with a much larger command set.

npm install
node lark.js status            # receiver, transmitters, battery, mute, firmware, settings
node lark.js watch             # live battery, Ctrl-C to stop
node lark.js set eq bright     # change a setting, then read it back to confirm
node lark.js mute 1            # mute / unmute a transmitter (1-4)
node lark.js unmute 1
node lark.js raw 1f            # send one read command, print the raw reply
node lark.js --selftest        # checks packet encoding, no device needed

Add --json to status, set, mute or raw for machine-readable output. lark set with no arguments lists the settings for the connected model. raw only works on the A1.

Lark A1 settings

set takes a name, or the raw bytes shown by lark status in decimal.

Setting	Values	Bytes	Verified on device
indicator	on, off	0, 1	Yes
reverb	off, small, medium, large	[on, level]: off keeps the level, sizes are 1 0 / 1 1 / 1 2	Yes
noise_cancel	off, weak, medium, strong	[on, level], same shape as reverb	Read only
eq	low, bright, balanced	1, 2, 3	Read only
voice_mode	mono, stereo	0, 1	Read only
voice_level	0–5	the app's steps 1–6	Read only
mic_recognition	off, on	0, 1	Read only
auto_power_off	15min, never	0, 1	Read only
signal_mode	normal, performance	0, 1	Shown, not settable
enhanced_mode	off, on	0, 1	Shown, not settable

"Read only" means the value names come from Hollyland's app and match what the device reports, but set hasn't been tried on hardware yet. set always reads the value back and exits with code 2 if the device didn't take it.

The device refuses most settings while every transmitter is off. The indicator and auto power-off still work.

signal_mode is the app's "Performance mode", a radio setting the app only shows when Hollyland's server allows it. enhanced_mode is a different radio setting the app sets on its own from your country. Both are left read-only so this tool can't put the radio into a mode that isn't allowed where you are.

To add a setting name: change it with set, check what physically changes, then add it to that model's settings in devices.js and to this table. When you confirm an untested model works, set tested: true on it and move its row in the table at the top.

Lark A1 protocol

Verified on a Lark A1 receiver (USB 3547:0407, firmware 1.0.2.12) with two paired transmitters. Value meanings come from the decompiled HollyAudio 3.0.6 Android app.

• Commands are HID feature reports, report ID 5, padded to 64 bytes: 05 03 AA DD <cmd> <len hi> <len lo> <payload…> EF. The 03 is required; without it the device returns a stale buffer instead of an error.
• Replies start 05 03 BB DD <cmd> <len hi> <len lo> <payload…> followed by a checksum byte, which this tool ignores. Requests need no checksum.
• Each setting has a read opcode (even) and a set opcode one below it (odd). A set takes the same payload the read returns and replies with one status byte: 0 is success, 255 means the target is off.

Opcode	Command	Notes
0x02 / 0x01	voice_mode	read / set
0x04 / 0x03	voice_level	read / set
0x06 / 0x05	reverb	read / set
0x08 / 0x07	eq	read / set
0x14 / 0x13	noise_cancel	read / set
0x22 / 0x21	indicator	read / set
0x24 / 0x23	mic_recognition	read / set
0x28 / 0x27	auto_power_off	read / set
0x40 / 0x3F	signal_mode	read / set (set not exposed)
0x46 / 0x45	enhanced_mode	read / set (set not exposed)
0x26 / 0x25	speaker_out	Hidden for the A1 in the app. Reads back empty
0x16	mute	payload [tx - 1, 1 muted / 0 unmuted]
0x0D	firmware	payload 0 receiver, 1–4 TX. Returns FF for a TX that's off
0x12	serial	payload 0 receiver, 1–4 TX
0x30	receiver MAC	little-endian
0x31	TX MAC	payload 0–3 for TX1–TX4. Answers even when the TX is off
0x1F	heartbeat	see below

Heartbeat (0x1F) payload, which is how Hollyland's app reads everything, once a second:

Byte	Field
0, 1	TX1, TX2 online
2, 3	TX1, TX2 battery %
4, 5	TX1, TX2 muted
6, 7	noise cancel on, level
8	voice level
9	voice mode
10	auto power-off
11	indicator (0 = on)
12	EQ
13, 14	reverb on, level
15	mic recognition
16	signal mode
17–22	TX3/TX4 online, battery, muted (4-mic firmware only; untested)

Not exposed by this tool: 0x0C reboot, 0x3C refresh receiver, 0x3D pairing, and the firmware-update opcodes 0x1C–0x1E, 0x2C, 0x2D and 0x3E. raw refuses anything that isn't a known read.

Reads come from the receiver's cached state and take about 0.5 ms, even for transmitters. They also work while the mic is recording.

node-hid opens the receiver exclusively, so while one process holds it, others get exclusive access and device already open. Open, send and close per operation rather than holding the device.

Untested models

Everything below comes from reading Hollyland's app. None of it has been run against real hardware, and the tool can't tell if a byte offset or value name is wrong until someone with the device tries it.

To limit the damage a wrong guess can do, these models only get three things:

• Status: one heartbeat command, the same one Hollyland's app polls.
• A short list of settings, each sent with the exact command and payload the app uses.
• Mute, on the M3 only.

raw is disabled, and nothing else is ever sent. Command numbers mean different things on different models; on the M3, 0x6003 is factory reset. set reads the heartbeat again afterwards and exits with code 2 if the value didn't change as expected.

Unlike the A1, these models use ordinary HID output and input reports rather than feature reports.

Lark C1 / M1 / Mini / M2 / M2S

Frame: AA DD <cmd> <target> <len hi> <len lo> <payload…>, zero-padded to 64 bytes, no checksum. Target is 0x40 for the receiver. Replies echo the command at byte 2 and carry the payload from byte 6. Set commands reply [1] on success.

Setting	Command	Values	Heartbeat byte
noise_cancel	0x06	weak 1, strong 2 (reads 0 when off)	6
volume	0x05	0–5. The C1 and M2S map the app's buttons 1–6 to 5 4 3 0 1 2; the others to 0–5	7
volume_lock	0x34	unlocked 0, locked 1	8
voice_mode (M2S)	0x18	mono 0, stereo 1	9
auto_power_off (M2S)	0x36	15min 0, never 1	10
indicator (M2S)	0x39	on 0, off 1	13

Heartbeat is command 0x10: bytes 0–1 are TX1/TX2 online and 2–3 their battery %. These models have no mute command. Noise cancelling on/off is a toggle (0x19), so it isn't exposed. Pick a level instead.

Hollyland's app hides some settings depending on model and firmware. For example, volume lock needs receiver firmware 2.0.0.31 or later on the M2. The tool shows every setting regardless.

Lark A2

Same frame as above.

Setting	Command	Values	Heartbeat byte
noise_cancel	0x06	weak 1, medium 2, strong 3	6
volume	0x05	0–5 (the app's steps 1–6)	7
voice_mode	0x18	mono 0, stereo 1, safety 2	9
auto_power_off	0x36	15min 0, never 1	10
indicator	0x39	on 0, off 1	13
voice_preset	0x3A	off, bright 1 0, low 1 1, balanced 1 2	14: bit 0 on, bits 1–7 preset

Byte 15 of the heartbeat holds mute (bits 0–1) and charging (bits 2–3) per transmitter. The A2 has no USB mute command.

Lark M3 and Lark Max 2

Frame: AA DD 06 <target> <ctrl> <count hi> <count lo> followed by one command, <id hi> <id lo> 01 <len hi> <len lo> <payload…>.

• M3: report ID 0x08 in front of the frame, target 0x00, ctrl 0x00, no checksum.
• Max 2: the command is wrapped in 5A FA 00 00 00 … 5E FE 00 00 00, ctrl 0x07, and the frame ends with an XOR of every byte. Target is 0x01 for the phone receiver and 0x02 for the camera receiver.

Model	Setting	Command	Values
M3	noise_cancel	0x1003	off, weak, medium, strong (payload [0, level, on])
M3	volume	0x100D	0–5 (payload [0, level])
M3	voice_mode	0x1005	mono, stereo, 4track
M3	mute	0x1001	payload [tx 1–4, 1/0]
Max 2	noise_cancel	0x6006	off, weak, medium, strong (payload [on, level])
Max 2	voice_mode	0x6008	mono, stereo, safety
Max 2	mic_recognition	0x6013	off, on

Heartbeats: M3 is 0x6000 (byte 0 online bits, 3–6 battery, 11 mute bits, 12–15 noise on/level, volume, channel mode). Max 2 is 0x600B (2–3 battery, 6–7 online, 11–12 noise, 17 channel mode, 28 mic recognition). The 4-channel M3 receivers (040D, 040F) show four transmitters.