APC Mini MK2 Communication Protocol for TouchOSC

Technical documentation and MIDI/SysEx protocol mapping for the APC Mini Mk2
Compiled and improved for custom software integration.

Quick Reference (TLDR)

Naming Convention

MIDI channels are described using the 1 to 16 standard.

Default MIDI Mapping

LED Control via MIDI Messages

The pad and button LEDs on the APC mini mk2 can be controlled by Note On messages on Port 1.

These are 3-byte messages determining three factors:

1. Pad/Button ID
2. Behavior: Solid, Blink, or Pulse.
3. LED Color:
   • Pads: RGB color, brightness, and animation settings.
   • Buttons: Single color LED state and animation settings (no brightness control).

You can control individual LEDs or send bulk commands to update the entire UI surface.

Example Message: To solidly light Pad 1 in red, send the following: 96 00 05

• 96 = MIDI Channel 7 (Determines LED behavior: Solid 100% Brightness)
• 00 = Note 0 (Pad ID: First Pad)
• 05 = Velocity 5 (RGB Color: Red)

Pad & Button IDs

The second byte in the MIDI message determines which pad or button you are targeting.
MIDI message construction changes depending on whether it is an RGB LED (pads) or a Single LED (buttons).

Pads (RGB Matrix)

Each pad is addressed via a Note message.

Example : Sending Channel 7 Note On 0 Velocity 5 will : Set Brightness to Full, Target the First Pad, Set Red Color (In Normal Mode)

Buttons (Single Color)

Note: The Shift button is not accessible via standard MIDI.

Button messages must always be sent on Channel 1.
Buttons only support single-color LEDs.
The behavior (On/Off) is set via the velocity, not the MIDI Channel.

• Velocity 0 = OFF
• Velocity 1 (and 3 to 127) = ON
• Velocity 2 = ON (Blink)

Example: Sending Channel 1, Note On 100, Velocity 1 will turn the first Track Button LED on.

RGB LED Behavior & Color

Behavior (Brightness & Animation)

RGB LEDs can be lit solid at varying brightness levels, or programmed to blink and pulse at different rates.
This behavior is determined by the MIDI Channel (1 to 16) sending the Note On message.

Using our previous example (96 00 05), if we change the first byte to 97 (Channel 8), the LED will pulse red at 1/16 notes, synced with the external clock rate.

Byte 1 Value	MIDI Channel	Function
0x90	1	On 10% brightness
0x91	2	On 25% brightness
0x92	3	On 50% brightness
0x93	4	On 65% brightness
0x94	5	On 75% brightness
0x95	6	On 90% brightness
0x96	7	On 100% brightness
0x97	8	Pulsing 1/16
0x98	9	Pulsing 1/8
0x99	10	Pulsing 1/4
0x9A	11	Pulsing 1/2
0x9B	12	Blinking 1/24
0x9C	13	Blinking 1/16
0x9D	14	Blinking 1/8
0x9E	15	Blinking 1/4
0x9F	16	Blinking 1/2

RGB Color Values

The hardware uses a predetermined palette of 128 RGB values assigned to specific velocities (Byte 3 in the message).
This palette is hardcoded and cannot be changed.

If we want to change Pad 1 to a solid orange, we send: 96 00 09

• 96 = Solid lit at 100%
• 00 = Pad 1
• 09 = Velocity 09 (Orange)

Velocity to RGB Color Reference:

• Black: 0
• White: 3
• Red: 5 or 72
• Green: 21 or 87
• Blue: 45 or 67
• Yellow: 13
• Pink: 53
• Cyan: 90

➡️ Access the RGB Mapping Google Sheet

Single LED Behavior & Color

The UI buttons utilize single-color LEDs and require a unique control message structure compared to the RGB matrix.

Example Message: To solidly light the Track Button 1 LED (which is physically restricted to red), send the following: 90 64 01

• 90 = MIDI Channel 1 (Note: This will always be 90 for single LED commands. RGB blink and pulse values do not apply to these buttons).
• 64 = Note 100 (Button ID: Track Button 1)
• 01 = Velocity 1 (LED Behavior: ON)

Use the reference table below to construct your single LED MIDI messages:

Byte Number	Hex Value	Decimal Value	Description
1	0x90	N/A	Channel 1, Note-On
2	0x64 to 0x77	100 to 119	Button ID (Reference the Button ID tables above)
3	0x00 0x01 0x02 0x03 to 0x7F	0 1 2 3 to 127	Velocity 0 = LED OFF Velocity 1 = LED ON Velocity 2 = LED BLINK Velocity 3 to 127 = LED ON

Protocol Examples

For quick reference, the shorthand notation 7 0 5 translates to Channel 7, Note 0, Velocity 5.

Here are common execution strings:

• Send Note-On 7 0 5 to light the first pad in red (Normal Mode).
• Send Note-On 7 63 5 to light the last pad in red (Normal Mode).
• Send Note-On 10 64 5 to light the first pad in red (Drum Mode).
• Send Note-On 10 127 5 to light the last pad in red (Drum Mode).
• Send Note-On 1 107 127 to light the first Track Button.
• Send Note-On 1 112 127 to light the first Scene Launch Button.

Mode Switching via SysEx

Whenever you change the device mode, a corresponding System Exclusive (SysEx) message is sent.
You can send these specific messages to force the controller into a new mode remotely, without pressing any hardware buttons.
This is highly useful for initialization sequences or ecosystem syncing.

• Normal Mode: F0 47 7F 4F 62 00 01 00 F7
• Note Mode: F0 47 7F 4F 62 00 01 01 F7
• Drum Mode: F0 47 7F 4F 62 00 01 02 F7

Bulk LED Message Formatting

RGB Matrix

To update the entire grid, pad values remain constant while the MIDI Channel and RGB color variables change.

• Format: 9X [Pad ID] XX
• 9X 00 XX through 9X 3F XX

The Hex prefix 9X translates to a standard Note On message, where X determines the MIDI Channel (0 to F = Channels 1 to 16).
Example: 90 01 05 translates to Note On, Channel 1, Note 1, Velocity 5.

9X 01 XX	9X 11 XX	9X 21 XX	9X 31 XX
9X 02 XX	9X 12 XX	9X 22 XX	9X 32 XX
9X 03 XX	9X 13 XX	9X 23 XX	9X 33 XX
9X 04 XX	9X 14 XX	9X 24 XX	9X 34 XX
9X 05 XX	9X 15 XX	9X 25 XX	9X 35 XX
9X 06 XX	9X 16 XX	9X 26 XX	9X 36 XX
9X 07 XX	9X 17 XX	9X 27 XX	9X 37 XX
9X 08 XX	9X 18 XX	9X 28 XX	9X 38 XX
9X 09 XX	9X 19 XX	9X 29 XX	9X 39 XX
9X 0A XX	9X 1A XX	9X 2A XX	9X 3A XX
9X 0B XX	9X 1B XX	9X 2B XX	9X 3B XX
9X 0C XX	9X 1C XX	9X 2C XX	9X 3C XX
9X 0D XX	9X 1D XX	9X 2D XX	9X 3D XX
9X 0E XX	9X 1E XX	9X 2E XX	9X 3E XX
9X 0F XX	9X 1F XX	9X 2F XX	9X 3F XX

Single LED UI Buttons

Button values and the MIDI Channel are constant, while the LED behavior (velocity) is variable.

• Format: 90 [Button ID] XX
• 90 64 XX through 90 77 XX

The Hex prefix 90 translates to a Note On message on Channel 1.
Example: 90 64 01 translates to Note On, Channel 1, Note 100, Velocity 1.

90 64 XX

90 65 XX

90 66 XX

90 67 XX

90 68 XX

90 69 XX

90 6A XX

90 6B XX

90 70 XX

90 71 XX

90 72 XX

90 73 XX

90 74 XX

90 75 XX

90 76 XX

90 77 XX

Advanced SysEx Operations

RGB LED Color Customization

Alternatively, RGB pad colors can be customized using SysEx commands to set one or several LEDs to a specific color profile.
The color is generated by sending three 8-bit values for Red, Blue, and Green.
Since standard MIDI only supports 7-bit messages, each component is expressed using MSB/LSB.

Byte Number	Value	Description
1	0xF0	MIDI System exclusive message start
2	0x47	Manufacturers ID Byte
3	0x7F	System Exclusive Device ID
4	0x4F	Product model ID
5	0x24	Message type identifier
6	<total MSB>	Number of data bytes to follow (most significant)
7	<total LSB>	Number of data bytes to follow (least significant)
8	0x00-0x3F	Start Pad
9	0x00-0x3F	End Pad
10	0x00-0x7F	Red Brightness MSB
11	0x00-0x7F	Red Brightness LSB
12	0x00-0x7F	Green Brightness MSB
13	0x00-0x7F	Green Brightness LSB
14	0x00-0x7F	Blue Brightness MSB
15	0x00-0x7F	Blue Brightness LSB
…	…	Repeat bytes 8-15 for each additional pad color change
<bytes total>	0xF7	MIDI System exclusive message terminator

Generic SysEx Inquiries & Introduction

Depending on the required software implementation, the APC mini mk2 will respond to the following MMC Device Enquiry and initialization messages.

Byte Number	Value	Description
1	0xF0	MIDI System exclusive message start
2	0x47	Manufacturers ID Byte
3	0x7F	System Exclusive Device ID
4	00x4F	Product model ID
5	<Message ID>	Message type identifier
6	<DataLengthMSB>	Number of data bytes to follow (most significant)
7	<DataLengthLSB>	Number of data bytes to follow (least significant)
8	n data bytes	Data field – n bytes long
n+8	0xF7	MIDI System exclusive message terminator

Device Enquiry

The APC mini mk2 supports the standard MMC Device Enquiry message.
These System Exclusive messages are part of the MIDI Machine Control Standard and do not follow the general format for Inbound System Exclusive messages.

Inquiry Request:

Byte Number	Value	Description
1	0xF0	MIDI System exclusive message start
2	0x7E	Non-Realtime Message
3	0x00	Channel to inquire. (Set to 0 for this protocol.)
4	0x06	Inquiry Message
5	0x01	Inquiry Request
6	0xF7	MIDI System exclusive message terminator

Inquiry Response:

The APC mini mk2 will respond to a Device Inquiry Request message with the following data:

Byte Number	Value	Description
1	0xF0	MIDI System exclusive message start
2	0x7E	Non-Realtime Message
3	<MIDI Channel>	Common MIDI channel setting
4	0x06	Inquiry Message
5	0x02	Inquiry Response
6	0x47	Manufacturers ID Byte
7	00x4F	Product model ID
8	0x00	Number of data bytes to follow (most significant)
9	0x19	Number of data bytes to follow (least significant)
10	<Version1>	Software version major most significant
11	<Version2>	Software version major least significant
12	<Version3>	Software version minor most significant
13	<Version4>	Software version minor least significant
14	<DeviceID>	System Exclusive Device ID
15	<Serial1>	Serial Number first digit
16	<Serial2>	Serial Number second digit
17	<Serial3>	Serial Number third digit
18	<Serial4>	Serial Number fourth digit
19	<Manufacturing1>	Manufacturing Data byte 1
20	<Manufacturing2>	Manufacturing Data byte 2
21	<Manufacturing3>	Manufacturing Data byte 3
22	<Manufacturing4>	Manufacturing Data byte 4
23	<Manufacturing5>	Manufacturing Data byte 5
24	<Manufacturing6>	Manufacturing Data byte 6
25	<Manufacturing7>	Manufacturing Data byte 7
26	<Manufacturing8>	Manufacturing Data byte 8
27	<Manufacturing9>	Manufacturing Data byte 9
28	<Manufacturing10>	Manufacturing Data byte 10
29	<Manufacturing11>	Manufacturing Data byte 11
30	<Manufacturing12>	Manufacturing Data byte 12
31	<Manufacturing13>	Manufacturing Data byte 13
32	<Manufacturing14>	Manufacturing Data byte 14
33	<Manufacturing15>	Manufacturing Data byte 15
34	<Manufacturing16>	Manufacturing Data byte 16
35	0xF7	MIDI System exclusive message terminator

Introduction Message

This message is sent before any other device-specific message (other than Device Enquiry).
It instructs the APC mini mk2 to perform necessary initialization and informs the firmware of the application version number so changes in the host application can be catered for.

Byte Number	Value	Description
1	0xF0	MIDI System exclusive message start
2	0x47	Manufacturers ID Byte
3	00x7F	System Exclusive Device ID
4	0x4F	Product model ID
5	0x60	Message type identifier
6	0x00	Number of data bytes to follow (most significant)
7	0x04	Number of data bytes to follow (least significant)
8	0x00	Application/Configuration identifier
9	<Version High>	application Software version major
10	<Version Low>	application Software version minor
11	<Bugfix Level>	Application Software bug-fix level
12	0xF7	MIDI System exclusive message terminator

Response from APC mini mk2 Introduction message:

Byte Number	Value	Description
1	0xF0	MIDI System exclusive message start
2	0x47	Manufacturers ID Byte
3	0x7F	System Exclusive Device ID
4	0x4F	Product model ID
5	0x61	Message type identifier
6	0x00	Number of data bytes to follow (most significant)
7	0x04	Number of data bytes to follow (least significant)
8	<Fader #1 Value>	Sends the current value of Fader #1.
9	<Fader #2 Value>	Sends the current value of Fader #2.
10	<Fader #3 Value>	Sends the current value of Fader #3.
11	<Fader #4 Value>	Sends the current value of Fader #4.
12	<Fader #5 Value>	Sends the current value of Fader #5.
13	<Fader #6 Value>	Sends the current value of Fader #6.
14	<Fader #7 Value>	Sends the current value of Fader #7.
15	<Fader #8 Value>	Sends the current value of Fader #8.
16	<Fader #9 Value>	Sends the current value of Fader #9.
17	0xF7	MIDI System exclusive message terminator

Hardware Control Mapping

Use the following reference data to determine the MIDI values corresponding to physical hardware controls and faders.

The following chart shows the MIDI Note # associated with each button.
This number will be used for the Inbound Note-On/Off values when the buttons are pressed, and Outbound Note-On messages to control the button’s LEDs, if applicable.

Button Name	Note #	Note #	Channel	LED	Port #	Notes
Track Button 1	0x64	100	0	Red	0
Track Button 2	0x65	101	0	Red	0
Track Button 3	0x66	102	0	Red	0
Track Button 4	0x67	103	0	Red	0
Track Button 5	0x68	104	0	Red	0
Track Button 6	0x69	105	0	Red	0
Track Button 7	0x6A	106	0	Red	0
Track Button 8	0x6B	107	0	Red	0
Scene Launch 1	0x70	112	0	Green	0
Scene Launch 2	0x71	113	0	Green	0
Scene Launch 3	0x72	114	0	Green	0
Scene Launch 4	0x73	115	0	Green	0
Scene Launch 5	0x74	116	0	Green	0
Scene Launch 6	0x75	117	0	Green	0
Scene Launch 7	0x76	118	0	Green	0
Scene Launch 8	0x77	119	0	Green	0
Shift	0x7A	122	0	None	0
Clip Launch Button 0-63	0x00 – 0x3F	0x00 – 0x3F	See Notes	RGB	See Notes	*Port 0, MIDI CH 00-0F used when in Session View. *Port 0, MIDI CH 09 used when in Drum Mode. *Port 1, MIDI CH 00 used in Note Mode.

Channel Faders & Master Fader

The eight Channel Faders (1 to 8) and the single Master Fader (9) send absolute position data via MIDI CC# on USB Port 0.

Control Name	CC#	CC#	Channel	Port	Notes
Fader 1	0x30	48	0	0	Value is the absolute position of the Fader.
Fader 2	0x31	49	0	0	Value is the absolute position of the Fader.
Fader 3	0x32	50	0	0	Value is the absolute position of the Fader.
Fader 4	0x33	51	0	0	Value is the absolute position of the Fader.
Fader 5	0x34	52	0	0	Value is the absolute position of the Fader.
Fader 6	0x35	53	0	0	Value is the absolute position of the Fader.
Fader 7	0x36	54	0	0	Value is the absolute position of the Fader.
Fader 8	0x37	55	0	0	Value is the absolute position of the Fader.
Fader 9	0x38	56	0	0	Value is the absolute position of the Fader.