MIDI Thru - probonopd/MiniDexed GitHub Wiki

MIDI Thru functionality can be used to forward MIDI messages which MiniDexed is receiving, e.g., from a MIDI controller such as a keyboard, to another device attached to MiniDexed, such as a computer or tablet.

Option MIDIThru=from,to in minidexed.ini will forward MIDI events from the device from to to.

Option MIDIThru2=another,yetanother in minidexed.ini will forward MIDI events from the device another to yetanother.

from/to can be:

• umidiN (USB MIDI device, N = 1...4) (the MiniDexed device is acting as a USB host, not as a USB device)
• ttyS1 (serial interface) (note that one can attach an adapter that can act as a USB device which is attached to a tablet or computer)
• ukbd1 (PC keyboard)
• udp (AppleMIDI rtpmidi and udp midi)

This can be used, e.g., to use piano learning applications and games like Synthesia on a tablet while using MiniDexed for MIDI input and sound output.

MIDIThru2 lets you do have an additional MIDI forwarding path. This implements an Apple RTPMidi <-> MIDI DIN bi directional bridge:

MIDIThru=ttyS1,udp
MIDIThru2=udp,ttyS1

Another use is if you have a USB MIDI keyboard and want to send data to both the serial port and RTPMidi:

MIDIThru=umidi1,udp
MIDIThru2=umidi1,ttyS1

If you're looking to minimise network traffic and you dont need MIDI clock or active sensing you can disable forwarding these messages with:

MIDIThruIgnoreClock=1
MIDIThruIgnoreActiveSensing=1

Clock in particular can be quite aggressive - 24 per quarter note. Over serial midi it's only a single byte but over rtp midi its a packet.