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midibox64 CC weirdness, and why it's bad to crosspost


gzifcak

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no, it's the same. turning pots sometimes causes data assigned to other pots to be sent, usually with a value of zero. maybe i didn't mention that sometimes it's the same pot's data that is all zeros. it seems like it will work fine, and then something happens to make the inputs clamp to ground or something, but only while the pots are turning. it's almost like a lowpass filtered square wave LFO with a pseudo random rate is being mixed in with the pot data, through an AND processor. at least that's how i would synthesize it.

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Sounds like an issue with the Vdd (+5V) line to the pots. If a bad soldering leads to a temporal voltage break (e.g. while a pot is turned), the voltage of all pots (or the pots which are supplied by the faulty Vdd branch) will drop to 0V

Best Regards, Thorsten.

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ah, thanks, that definitely makes sense. so i've gone over all the vdd connections and reheated to make sure they're good joints (definitely as solid as any i've made in years of analog diy).

i'm still getting the same behavior. i monitored the voltage across the pots with a meter as i turned the pots, and it stays rock solid. i get the zeros some times for a few seconds, definitely long enough to register on a meter if that was happening.

any other ideas?

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another observation:

when a pot is glitching, the speed of the turn makes a difference. if i turn the pot slowly, i get almost all glitch messages, with a few correct messages in between chunks of zeros. if i turn the pot faster, i can squeeze more correct messages in between the chunks of zeros.

so the glitch appears to be active for some sort of non-random period?

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Hi Gzifcak! 

no, it's the same. turning pots sometimes causes data assigned to other pots to be sent, usually with a value of zero. maybe i didn't mention that sometimes it's the same pot's data that is all zeros. it seems like it will work fine, and then something happens to make the inputs clamp to ground or something, but only while the pots are turning.
I have seen a couple of builds where a panel mounted power inlet jack connects one side of the wall wart power supply to the enclosure, and the pots (mounted to same enclosure) tied the chassis to system ground, etc.  (symptoms vary based on the pots, the power jack, whether power pack is AC or DC out, etc.)

I have also seen similar symptoms caused by lack of isolation between the CORE and PC via the MIDI interface.....Some PC power supplies are so noisy that if you tie the CORE ground to the PC ground it wont even boot (Switch mode power supplies used in PC's are typically high noise/ripple).  I won't even get into the ground differential issues present with separate linear and switch mode supply grounds tied together.  ;)

That said does is there anything that changes the symptoms?  Do you have a display on it so you can disconnect MIDI to the PC and see if things change?  What kind of power jack are you using (if any)?  Are the pots mounted in a metal enclosure/panel and is that grounded to anything else (sitting on other gear)?

Sometimes with similar symptoms it's more about other things that are connected to the same ground than anything else you might have done wrong during the build. 

i'm only using 2 so maybe i'll swap them out and see what happens.
I'm thinking you probably have everything not used grounded at CORE:J5 already, but keep in mind if your app is trying to read hardware that isn't there or not properly grounded it might act up like this.  If using only two multiplexer chips all but the first two analog input lines on J5 should be tied to ground....sorry if I'm repeating advice already written.  ;)

Best regards

SmashTV

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hi! thanks for the tips. i do have a power jack mounted on the metal chassis, and there probably is a path between that and the pot ground. i'll disconnect that and see what happens.

i have tried the midibox plugged into a nord micromodular, and i can hear that it exhibits the same behavior.

all unused inputs are tied to ground.

thanks!

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i just noticed something:

once a pot starts glitching, it looks like it might switch from changing the values of a single CC, to scrolling through CCs with a value of zero:

00051148  1  --    B0    0D    50    1  ---  Control Change       

0005114B  1  --    B0    0D    4F    1  ---  Control Change       

00051156  1  --    B0    0D    4E    1  ---  Control Change       

00051162  1  --    B0    0D    4C    1  ---  Control Change       

0005116C  1  --    B0    0D    4B    1  ---  Control Change       

00051174  1  --    B0    0D    4A    1  ---  Control Change       

0005117B  1  --    B0    0D    48    1  ---  Control Change       

00051185  1  --    B0    0D    47    1  ---  Control Change       

0005118E  1  --    B0    0D    46    1  ---  Control Change       

000511A3  1  --    B0    0D    45    1  ---  Control Change       

000511B0  1  --    B0    0D    44    1  ---  Control Change       

000511BA  1  --    B0    0D    42    1  ---  Control Change       

000511C4  1  --    B0    0D    41    1  ---  Control Change       

000511CE  1  --    B0    0D    40    1  ---  Control Change       

000511D8  1  --    B0    0D    3F    1  ---  Control Change       

000511E1  1  --    B0    0D    3E    1  ---  Control Change       

000511EC  1  --    B0    0D    3D    1  ---  Control Change       

000511FB  1  --    B0    0D    3B    1  ---  Control Change       

00051209  1  --    B0    0D    3A    1  ---  Control Change       

0005120F  1  --    B0    00    00    1  ---  CC: Bank MSB         

00051210  1  --    B0    01    00    1  ---  CC: Modulation       

00051210  1  --    B0    02    00    1  ---  CC: Breath           

00051211  1  --    B0    03    00    1  ---  Control Change       

00051212  1  --    B0    04    00    1  ---  CC: Foot Controller 

00051213  1  --    B0    05    00    1  ---  CC: Portamento Time 

00051214  1  --    B0    06    00    1  ---  CC: Data Entry MSB   

00051215  1  --    B0    07    00    1  ---  CC: Volume           

00051216  1  --    B0    08    00    1  ---  CC: Balance         

00051217  1  --    B0    09    00    1  ---  Control Change       

00051218  1  --    B0    0A    00    1  ---  CC: PAN             

00051219  1  --    B0    0B    00    1  ---  CC: Expression       

0005121A  1  --    B0    0C    00    1  ---  Control Change       

0005121B  1  --    B0    0D    00    1  ---  Control Change       

0005121C  1  --    B0    0E    00    1  ---  Control Change       

0005121D  1  --    B0    0F    00    1  ---  Control Change       

0005121E  1  --    B0    10    00    1  ---  Control Change       

0005121F  1  --    B0    11    00    1  ---  Control Change       

00051220  1  --    B0    12    00    1  ---  Control Change       

00051221  1  --    B0    13    00    1  ---  Control Change       

00051222  1  --    B0    14    00    1  ---  Control Change       

00051223  1  --    B0    15    00    1  ---  CC: 21 (E-MU)       

00051224  1  --    B0    16    00    1  ---  CC: 22 (E-MU)       

00051225  1  --    B0    17    00    1  ---  CC: 23 (E-MU)       

00051226  1  --    B0    18    00    1  ---  CC: 24 (E-MU)       

00051227  1  --    B0    19    00    1  ---  Control Change       

00051228  1  --    B0    1A    00    1  ---  Control Change       

00051229  1  --    B0    1B    00    1  ---  Control Change       

0005122A  1  --    B0    1C    00    1  ---  Control Change

am i interpreting this correctly?

does this offer any insight?

thanks,

greg

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my ini file has:

[sNAPSHOT_AT_POWERON]

  disabled

[AUTO_SNAPSHOT]

  disabled

in fact, here is my entire ini file. let me know if there is a problem:

[TYPE]

  midibox64

[bANKNAME]

  "SFB Example    " 

[CONNECTED_POTS]

  16

[GLOBAL_MIDI_CHANNEL]

  0

[MORPH_BANK]

  1

[MORPH_POT_GLOBAL]

  0

[MORPH_POT_G1]

  0

[MORPH_POT_G2]

  0

[MORPH_POT_G3]

  0

[MORPH_POT_G4]

  0

[sNAPSHOT_AT_POWERON]

  disabled

[AUTO_SNAPSHOT]

  disabled

[MIDI_MERGER]

  enabled

[POT_BEHAVIOUR]

  normal

[sEND_PC_ON_BANKCHANGE]

  disabled

[RECEIVE_PC_FOR_BANKCHANGE]

  disabled

################################################################################

[POTS]

    # Pot Row 1

    1  =  B0 00 [00-7F]  "CC # 0" DEC|

    2  =  B0 01 [00-7F]  "CC # 1" DEC|

    3  =  B0 02 [00-7F]  "CC # 2" DEC|

    4  =  B0 03 [00-7F]  "CC # 3" DEC|

    5  =  B0 04 [00-7F]  "CC # 4" DEC|

    6  =  B0 05 [00-7F]  "CC # 5" DEC|

    7  =  B0 06 [00-7F]  "CC # 6" DEC|

    8  =  B0 07 [00-7F]  "CC # 7" DEC|

    9  =  B0 08 [00-7F]  "CC # 8" DEC|

    10  =  B0 09 [00-7F]  "CC # 9" DEC|

    11  =  B0 0A [00-7F]  "CC #10" DEC|

    12  =  B0 0B [00-7F]  "CC #11" DEC|

    13  =  B0 0C [00-7F]  "CC #12" DEC|

    14  =  B0 0D [00-7F]  "CC #13" DEC|

    15  =  B0 0E [00-7F]  "CC #14" DEC|

    16  =  B0 0F [00-7F]  "CC #15" DEC|

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No, in such a case you don't need to reconfigure the software. But you should doublecheck, that R9 of the core module (10k pull-up resistor) is connected correctly to avoid randomly triggered button events (or functions).

Do you notice the same with the ain64_din128_dout128_v2_0 application?

Best Regards, Thorsten.

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i reheated the joints, and i'm not getting a fast stream of notes anymore, but i get a combination of note-on, note-off, and various CC messages when i turn a pot. is this normal?

still getting the same behavior with my modified app. also when i send the sysex for my app, i get a bunch of note offs when it starts sending, then it calms down and sends the checksums.

i wonder if it's my pic socket? no, just bypassed it for the pull-up resistor, no change.

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whoa! i think i got it! there was a bridge from a trace connected to the pull-up resistor to another trace nearby. it was hard to catch because it was at a solder joint and looked like it was supposed to be connected. let me test it for a while and make sure it's fixed.

thanks thorsten for drawing my attention to the pull-up resistor!

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