schurer

on the road, preparing some patches for a stage play, need some dirty advice: what is the best way to establish bi-directional midi communication between harware controllers and gui's, so that both reflect either states? i.e. setting values in the gui update states on the controller and vice versa...basic, i know, but only having crude "workarounds"...

loss-of-memory-bi-directional-midi-communication

depends where the final values go to, I'm assuming you have a GUI which controls your hardware, then the hardware out makes the actual sound. To update the GUI you'd need to send the hardware's values back (if you are able to change the states on the hardware directly) but you need to pass any value through "set $1" otherwise you'll get an endless loop (stack overflow). [ctlin] and [ctlout] should be what you need to communicate.

Either way, in situations like this, you nearly always need a "set $1" unless an object you're using has built-in stack overflow control, like [pattr].

not sure if there is a best way, it realy depends on the hardware end.

when the hardware controller has a knob to update itself from the software,

it will be a risk to implement controlling this function from the software.^^

otoh it would be stupid to depend on that hardware knob for updating.

normally it is no problem to control A from B and B from A a the same time.

when B is a hardware this is not different from B beeing another max patcher.

trouble starts when you want to be able to control A and B from each other at the

same time, like you can see it in the usual DAW controllers.

the most basic contruction in this case will be something like:

input - [change] - [prepend set] - store/GUI

and after setting the parameter/GUI the input will also bang the parameter:

another [change] is required before outputting to the hardware.

this (or more) will make slave and "total recall" possible in both directions.

when the hardware controller has a knob to update itself from the software,
it will be a risk to implement controlling this function from the software.^^

normally it is no problem to control A from B and B from A a the same time.
when B is a hardware this is not different from B beeing another max patcher.

trouble starts when you want to be able to control A and B from each other at the
same time, like you can see it in the usual DAW controllers.

alright, thank you folks. I did actually use the change object with deferred output to update gui/controller states. I don't think that to prepend setting does much outside the ability to trigger the message at a given point in time. It still feels clumsy to me, as there is the overhead of checking back the hardware for the state it was in before. But you are right, that the hardware should actually care of this process...

loss of memory: bi- directional midi-communication