Hi guys, I have recently found a really strange problem:
after assigning midi cc to controls on the stompbox delay (on / off, time, feedback) the audio has been downgraded.
For contextualization midi cc are also connected to physical knobs by harnessing the gpio ports.
did anyone find the same problem?
Thanks for support
what does that mean? you are also controlling the values like feedback with a pot? if so, then most likely you are hearing the jitter from the analog in and you perceive it as a "downgrade". the feedback amount will always be slightly changed because the adc has some noise...
there are numerous posts on the forum about this issue and how to solve them.
or is it something else you are seeing? (try to disconnect the gpio from the stomp box object and see if the problem persists)
Thank you lokki for kind reply 
Yes, I control the parameters with physical knobs (eg. feedback, time), I’ve used midi cc objects and map the controls to them.
Without mapping and moving parameters from the patcher no “downsampling” occurs, after mapping delay sounds like shit.
How does your patch look like (just an example of the "gpio + midi cc" controlling parameters)? I don't understand how you control a parameter with both MIDI CC mapping and gpio object. It doesn't seem to make sense to control a parameter with two sources at the same time. Or I misunderstood your explanation...
Knobs sends signals to gpio ports (in), gpio ports sends signals to midi objects, midi objects sends cc signals to modules (chosen parameter). It works, I take theese infos from the forum 
ok, what happens if you disconnect the gpio and modulate the midi cc's via a dial from the axoloti patcher? does it still happen? as i said, i suspect this is a noise-floor issue...
I’ve replaced the gpio/in/analog with a dial and it works properly. Do you think it’s a soldering problem? In my patch there are other processing stages (pitchshift, reverb, filter) also connetcted to pots but they are unaffected by the “downsampling”. So I assume that it isn’t a floor noise issue, right?
The amount of downsampling is like to pass from 16bits to 8-6bits...there’s nothing of the original sound 
it’s excellent as a destroy machine but it isn’t what I want 
To check if it's a soldering problem, modify your patch, assign the malfunctioning parameter to a pot that you know works well with another parameter, and see if the quality issue is still there...
@KF78 , Id need to see the patch to make any real sense
BUT... if you are taking both midi and gpio as input onto one parameter, perhaps these are 'fighting each other' i.e. midi suggesting one value and gpio another due to 2 'knob positions' (bare in mind the midi and gpio values are always present), this could possibly be aggravated since the gpio value will have a certain amount of noise.
so... id expect in this scenario your patch would need to
a) smooth the gpio values
b) use something like 'hook' to ensure that at any one time, either the midi value OR the gpio value is used.
(b) would only be needed if your are inferring absolute values... if you are summing midi + gpio (and then ensuring the range does not go out of bounds) , then this would not be necessary.
other thoughts, are if you are some how 'quantising' an audio stream against a midi value... where you might been to smooth it, but thats more likely to be noticeable only where you change the midi value.
(but could happen if you have a midi controller sending jittery cc values)
anyway, just thoughts as without seeing a patch is unclear what your doing.
Id recommend, you create a small patch, which has the smallest number of objects that can demonstrate the issue.
Why pitchshifter, filter and reverb works properly with the exactly same setup?
could it be a soldering problem from gpio to pots?
honestly , by giving small pictures its impossible to say...
soldering problem, have you looked at the data from the gpio? does it look noisy?
you could try switching which pots control which parameters - does that alter anything?
(unlikely all your joints are bad? especially if you say you have some working ok)
in your picture, you do have some inconsistency, the way your using change with the midi cc is incorrect, in the first few instances... due to execution order... i.e. you are doing the change after the cc... though whilst being logically incorrect, its probably not making any practical difference.
also, I would not even be sending the gpio via the cc internal bus, that makes little sense... you could connect these directly , no? if the object your using, does not have an inlet, then you should be using mod sources.
for this patch I got started here in the forum, I asked for information on how to control the parameters with pots and I was given the solution you see in the screenshot. If you have a better method of doing the same job I'm very happy to know it 
the issue with using midi , is by definition it quantises everything to 7bit ..
how is better depends on the object you are targeting, if they have inlets, you should be using these, if not then you should use mod source - this will keep it all 32bit, and also mean less conversions (which can introduce numerical inaccuracies)
also with pots, you need to pass the values thru a low pass filter (or similar) , to remove the noise, which otherwise cause a high frequency 'warbling' , as parameter values are oscillated at 3khz
... also check the threads on 'execution order', you should always place your change into trig , before the object you want to trig.
checking for noise, simplest way is to connect the gpio output to a scope, and look to see if how much the value is fluctuating .. you might need to scale the output, to see the fluctuations clearer.
to see what is normal (some noise is to be expected) check all of your pots, to see which are better/worst... if some are obviously worst, then they probably need re-soldering.
... afterwards, you can also use this visualisation, to see if your low pass filtering is working as expected.
I suspect, its mainly a patching issue... and that once you filter, and don't go thru midi, there might still be a bit of noise.
there is a possibility you may want to also use a smooth object to smooth the k-rate inputs further, but these probably is not necessary once you have an LP on the gpio outputs... but if you combine external midi too, then it will be necessary.
I understand, in my case there’s only objects with inlets so maybe in future projects I’ll use the other method (mod source)
Yes!!! It works finally 
I place a lpf on every gpio output and now works great! Thanks a lot for your precious help! 
