Problem with CC not going to zero

[bolau]

Hi Rob, hi audiofront fans,

I use roland expression pedals and the great Roland RPU-3 pedal unit with a MIDI Expression Quattro to control effect plugins like Turnado or Transit Ableton for my Future-Pop Liveband "Synamoon". I love the overla setup, but there's one annoying quirk:

When I let go of the pedal (with a spring-loaded RPU-3 pedal), or move my other expression pedal up quickly, sometimes the last MIDI event being created is not a zero, but some value between 1 and 10, although the MIDI expression GUI shows a zero at the end. My understanding is that there's a filter in the firmware that suppresses MIDI events if there was no sufficient voltage change, while the GUI shows all changes. But here's the catch: it seems that we would need one additional event at the end of an event train to be safe that the latest generated MIDI event is actually the latest measured value, especially when it's a zero.

Here's a screenshot that shows this situation:

Screenshot 2025-04-27 at 00.28.12.png (372.15 KiB) Viewed 1037 times

And here's a video showing some pedal presses, with the problem occuring two times (screenshot was taken at the end):
https://borislau.de/midi_expression.mp4

The issue for me is, that when using the pedal with the Turnado or the Transit effect plugin, there's often a big difference between 0 (no effects) and 1-127 (effect with varying degree of intensity). So even if the pedal is stuck at only two, the effect gets stuck and I don't get my dry signal back.

Could you please fix is in a future firmware revision?

By the way, changing the pedal calibration by moving the lower threshold up doesn't help here...

All the best from Germany,
Boris

[Rob]

Hi Boris,

Thanks for reporting this issue. I'll look into it on Monday. Can you please confirm what firmware version you are using?

Regards,
Rob

[Rob]

I just had a look at the code, and this doesn't *seem* to be possible. If the measured value goes to zero, the MIDI Expression will definitely send the zero. What are application are you using to Monitor the MIDI? Does MIDI Expression's built-in MIDI Monitor also show this issue? I'll try to investigate further on Monday, but I can only do limited testing because my studio is out of commission for another week or so while we do some repairs to our balcony that connected to an adjacent wall.

[bolau]

Hi Rob,
thanks for getting back to me so quickly. My current firmware is 2.9.5.15, which is also shown as latest firmware option.

Do you expect it to also send the final zero if it was measured very shortly after the last non-zero MIDI event?

I used "MIDI Monitor", because I didn't know MIDI Expression has one built-in
Now I checked again with the built-in monitor, it's just the same. Here's a screen video, where you can see that the last created event is value 11, while your GUI actually shows the final zero:
https://www.borislau.de/midi_expression2.mp4

By the way, this effect also occurs on the other end of the range, when I fully press the pedal. Here's a video that shows three full pedal presses. The third time, the midi events only go up to 117, while the GUI shows the correct 127:
https://www.borislau.de/midi_expression3.mp4

Thanks for looking into this and good luck with your balcony.

[Rob]

Fixed for the next build. Thanks.

[bolau]

Awesome, that's exciting news

[Rob]

You can get the fix from here:

viewtopic.php?f=26&t=2350

[bolau]

Tested 2.9.5 BETA, the issue seems fixed.
Thanks for your amazing customer service!