Receive sysex response?

HansR · February 11, 2026, 9:23am

Hello,
From discussions in the past I understand that it is not possible to receive (stray) sysex messages. That is not what I am looking for either.

But is it possible to receive a reply to a sysex message?
Example from the documentation of the Launchpad Mini Mk3:

Device Inquiry message
The Launchpad Mini [MK3] responds to the Universal Device Inquiry Sysex message, which can be used to identify the device. This exchange is as follows:

Host => Launchpad Mini [MK3]:
Hex: F0h 7Eh 7Fh 06h 01h F7h
Dec: 240 126 127 6 1 247

Launchpad Mini [MK3] => Host (Application):
Hex: F0h 7Eh 00h 06h 02h 00h 20h 29h 13h 01h 00h 00h <app_version> F7h
Dec: 240 126 0 6 2 0 32 41 19 1 0 0 <app_version> 247

I want to do something similar for my LPD8, query the current settings. Is that somehow possible? How do I get to the reply data?

There seems to be no such thing as a lib_zyncore.dev_receive_midi_event(self.idev_in)

Kind regards,
Hans.

jofemodo · February 11, 2026, 11:11am

Hi @HansR !

You can find good examples of how to send and receive SysEx responses from ctrldev drivers in current drivers like:

github.com/zynthian/zynthian-ui

zyngine/ctrldev/zynthian_ctrldev_launchpad_mini_mk3.py

oram

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# ******************************************************************************
# ZYNTHIAN PROJECT: Zynthian Control Device Driver
#
# Zynthian Control Device Driver for "Novation Launchpad Mini MK3"
#
# Copyright (C) 2015-2024 Fernando Moyano <jofemodo@zynthian.org>
#                         Brian Walton <brian@riban.co.uk>
#
# ******************************************************************************
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of
# the License, or any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

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The more complete example is the new APC40 driver, that includes Universal Device Inquiry code, but it’s only available in vangelis branch:

github.com/zynthian/zynthian-ui

zyngine/ctrldev/zynthian_ctrldev_akai_apc_40_mk2.py

vangelis

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# ******************************************************************************
# ZYNTHIAN PROJECT: Zynthian Control Device Driver
#
# Zynthian Control Device Driver for "Akai APC 40 mk2"
#
# Copyright (C) 2025 Brian Walton <riban@zynthian.org>
# API: https://cdn.inmusicbrands.com/akai/attachments/apc40II/APC40Mk2_Communications_Protocol_v1.2.pdf
#
# ******************************************************************************
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of
# the License, or any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

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Regards,

HansR · February 11, 2026, 1:07pm

Thanks @jofemodo,

I tried that already but elif ev[0] == 0xF0: never gets hit. I didn’t know if that was caused by the device not responding or this clause not working.

I still don’t actually know what the cause is, but now I can search more specifically.

AL1-1956 · February 11, 2026, 9:42pm

Hello @HansR

If you have a PC with windows you can use Midi-OX to see if your device responds to universal device inquiry

For my LP mini MK3 I get

If you are on other OS there are probably tools that can make the same job

Hope it can help

Alain

HansR · February 12, 2026, 1:12pm

Hi @AL1-1956

Thanks for the tip, the device responds to universal device inquiry,

For this device and this situation I need the current device settings, and change them so the bottom 4 knobs are assigned the right CC values while the rest of the settings remain intact.

The LPD8 is not very versatile in this situation, you can ask all parameters at once or you can set all parameters at once.

I still have some problems sending more than one sysex and processing a respons. This may be the right time to start a separate thread.

AL1-1956 · February 12, 2026, 1:50pm

Hello @HansR

What I do in this kind of situation is a try and error process

I first dump the initial setting in a sysex file and then try to identify where values in hexa are gathered

Since I know what initial values are it is not very hard when I think I have found the right place with a binary editor like “Neo” I change this value and dump back the modified file to the device and see if I have done right and what button or pot has changed his CCnumber.

Just saying …

Alain

HansR · February 12, 2026, 1:55pm

I’m lucky, I found the complete structure:

Problem is not the content, but timing I’m afraid. But that is all part of the hobby

jofemodo · February 12, 2026, 2:08pm

I forgot to mention that the device inquiry wont work in Oram. You have to use Vangelis for this to work.

Regards