QMidiArp testing

I’ve been having a go at getting QMidiArp going in my Zynth and today I found something that works rather well.

Now, I’m afraid here things sketchy because I can’t remember how I installed them. I’m pretty sure I downloaded it from Sourceforge compile as per the README. The fiddly bit is you then need to copy the appropriate .o files from qmidiarp-0.6.5/src/.libs/ into the relevant lv2 dirs, and then copy the resulting qmidiarp_{arp,lfo,seq}.lv2 folders to /zynthian/zynthain-my-plugins/lv2 and enable them in the web-ui.

The directory trees should end up like

├── manifest.ttl
├── qmidiarp_arp.so
├── qmidiarp_arp.ttl
├── qmidiarp_arp_ui.so
└── qmidiarp_arp_ui.ttl
├── manifest.ttl
├── qmidiarp_lfo.so
├── qmidiarp_lfo.ttl
├── qmidiarp_lfo_ui.so
└── qmidiarp_lfo_ui.ttl
├── manifest.ttl
├── qmidiarp_seq.so
├── qmidiarp_seq.ttl
├── qmidiarp_seq_ui.so
└── qmidiarp_seq_ui.ttl

There isn’t a MIDI layer for adding these plugins using the zynth-ui so I got creative and used MOD-UI

The connections go from My USB keyboard in on the left to the Zynthian Main out on the right. If you hover the socket it should tell you which is which.

Qmidiarp listens on all midi channels, and by default outputs on Ch#1. So I set my keyboard to Ch#2, and loaded in a synth engine listening on Ch#1.

Once you save the mod-ui pedalboard you can load it using the zynthian-ui, it also exposes the arps as presets you can switch between. You can use the same methodology for qmidiarp_lfo and qmidiarp_seq.


Nice work! Looks very promising!

Hi @Baggypants that’s nice. Tried to figure it out. After some issues with qt4 and qt5 dependencies, I was able to generate the files as mentioned and copied them to the appropriate folders. However, when I try to load them in the MOD UI browser interface, there comes an error message, “Error adding effect”.

Update: now I know what causes the error - qmidiarp needs to be compiled directly on the Raspberry.

Ok, seems to work now within MOD UI, but editing the patterns seems only possible in the *.ttl files.
I tried another way, i.e. to launch qmidiarp via X11 connection to zynthian.
On the Zynthian, I installed qmidiarp from repositories (apt-get install qmidiarp).
However, I cannot figure out how to route the midi signals to and from qmidiarp and what settings on the zynthian might affect it.
My setup is as follows: I have an external midi keyboard, attached via USB, sending on midi channel 2. Then, I have a small synth attached to the 5 pin “Midi Out” socket, listening on channel 1. Accordingly, in qmidiarp, I set Output Channel to 1 and Input to Channel 2. But nothing happens. Event log stays empty.
In Zynthian admin menu, i have unchecked single channel mode. Don’t know if that matters. What am I doing wrong?

You need to plug the things together yourself. Install apt install patchage and run it through the X Forwarding.

That was the missing piece :grinning:! Thank you!

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