I build a small pdscript to convert midinotes into gate + v/oct for the analog outputs. When connecting a midikeyboard over usb to the board everything works as expected. Now i want to do the same but sending the midinotes from my daw instead of a midikeyboard. Connecting the bela to my computer its shows up as mididevice "Bela MIDI 1" which is selectable from my daw. Unfortunatly sending midinotes from my daw using this midi port, my pdscript on the belaboard doesnt receive anything.

Do i have to enable somthing to make this work? How could i solve this issue?

You need to select a different MIDI interface on the board. By default, Pd uses the one that is connected via USB directly to the Bela, which is normally called hw:1,0,0 (or none, if that is not available). The MIDI interface over USB to your computer, is called hw:0,0,0. To add MIDI interfaces to Pd on Bela, you need to send an appropriate message to bela_setMidi, e.g.:

[loadbang]
|
[hw 0 0 0 (   <<< this is for hw:0,0,0
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[send bela_setMidi]

This is documented in the 08-PureData/hello-midi and 08-PureData/midi-cv-midi. In fact, the latter example already does more or less what you want to do (i.e.: CV to MIDI to CV).

    giuliomoro The MIDI interface over USB to your computer, is called hw:0,0,0.

    just for reference, i have a setup here, where the MIDI interface over USB is moved away from hw:0:0:0 when an arduino with usb-midi is attached (mocolufa firmware). it is consistent though (happens every time i plug in the arduino at boot), so not a big deal.

        lokki is moved away from hw:0:0:0 when an arduino with usb-midi is attached (mocolufa firmware).

        Good to know, what does amidi -l look like in that case?

          can't check at the moment, but i am pretty sure usb-midi moves to 2:0:0 and usb-host connected midi device stays on 1:0:0

          here it is:

          root@bela:~# amidi -l
Dir Device    Name
IO  hw:0,0,0  MocoLUFA MIDI 1
IO  hw:1,0,0  QuNexus MIDI 1
IO  hw:1,0,1  QuNexus MIDI 2
IO  hw:1,0,2  QuNexus MIDI 3
IO  hw:2,0    f_midi