I have a midi shield with in, out and thru ports on an Arduino Uno. The program is running some switches, a foot pedal and merging a keyboard into the midi out. I have several controllers that are using USB connections into the computer. I would like to put them into my merge unit. The USBH_MIDI says you can have several USB inputs from a hub (I assume a powered USB hub) fed into a USB shield and out through a standard 5 pin midi port. It also says this is not a computer interface. I have a Focusrite A/D interface for my instruments and mics that has a standard midi input and output. Could I use a USB shield to merge all of the midi inputs and feed it to my computer through the Focusrite interface. The purpose is to have only one midi input showing for my programs as several of them do not allow more than one input. I am presently using Loopmidi and MidiOx to merge everything but it requires setting up every time I startup the computer. Any advice or suggestions would be appreciated.

I think it would be much easier to route all USB MIDI inputs to a virtual MIDI port on the computer using software.
On Linux, I use Qjackctl to do all my MIDI routing, and I think there are Windows and Mac alternatives as well.

I've seen a lot of struggle with USB host shields.

What program are you using that doesn't allow more than one MIDI input? Most (if not all) professional and open source audio software I've used supported multiple MIDI inputs. Both for recording instruments and for MIDI control.


The program which I use often is Amplitube 4 and it only allows one midi input for controls. As you say Ableton Live and most of the others I have like Guitar Rig have multiple inputs. I am using loopMIDI which is a virtual port and midiOx to merge all of the inputs into loopMIDI so that is my work around. I am just trying to consolidate the inputs as much as possible. It sounds as if the USB might be questionable and not reliable. There are units from a Canadian company, iConnectivity, that will take both the standard midi inputs and USBs and merge them into one but I like to build things myself, if possible. Thanks for the advice.