MIDI CC for Volca start / stop /record

chris-korg · Post by **chris-korg** » Tue Jan 13, 2015 9:08 pm

I'm testing my new midi-keyboard samson graphite 25 beeing directly connected to Volca Keys.

Midi CC for starting the sequence works (cc148)
Midi CC for stopping the sequence works (cc150)
even cc149 works for continuing the sequence from the step where it has stopped (which is an interesting feature)

BUT

what is the MIDI CC for "REC" ??? (to start recording a sequence) - I can't find it...

JoyrexJ9 · Post by **JoyrexJ9** » Wed Jan 14, 2015 8:09 am

How on earth did you figure out cc148 and cc150 would do anything?!

There's no mention of these in the Volca Keys MIDI chart, and I can see no mention of them in the MIDI standard CC parameter numbers either

chris-korg · Post by **chris-korg** » Thu Jan 15, 2015 11:37 am

Just "try and error"

I've tested now my Volca Bass - same situation.

JoyrexJ9 · Post by **JoyrexJ9** » Sat Jan 17, 2015 6:41 pm

How did you send those CC messages (148, 150)? Were these NRPNs? Standard MIDI CC numbers only go up to 127
What values did you send?

chris-korg · Post by **chris-korg** » Sun Jan 18, 2015 8:57 am

On my midi-keyboard I just assigned
- transport knob "PLAY" MIDI-CC 148
- transport knob "STOP" MIDI-CC 150
- transport knob "REC" MIDI-CC 149 (=Continue, as I did not find MIDI CC
for REC so far)

Tested in the meanwhile Volca Beats (works as well) and Volca Sample.

With my Volca Sample I do have a problem:
it receives the MIDI-CCs BUT for CC 148 and CC 149 it reacts with a delay of approx. 1 second - there seems to be some bug in the firmware...

teknoid · Post by **teknoid** » Thu Jan 22, 2015 1:10 pm

Interesting info!
Beats me too how you got higher midi cc than 127...and that they work!

for your problem, I take it you did the update to version 1.22?

chris-korg · Post by **chris-korg** » Thu Jan 22, 2015 3:47 pm

Yes - it is Firmware update 1.22

billyjoker · Post by **billyjoker** » Tue Aug 23, 2016 9:47 am

Hi, nice work you've got but i really want to program my MPK49 Keyboard as you did, but the problem is obvious... How to assign more than 127??

chris-korg wrote:On my midi-keyboard I just assigned
- transport knob "PLAY" MIDI-CC 148
- transport knob "STOP" MIDI-CC 150
- transport knob "REC" MIDI-CC 149 (=Continue, as I did not find MIDI CC
for REC so far)

Tested in the meanwhile Volca Beats (works as well) and Volca Sample.

With my Volca Sample I do have a problem:
it receives the MIDI-CCs BUT for CC 148 and CC 149 it reacts with a delay of approx. 1 second - there seems to be some bug in the firmware...

Eamoex · Post by **Eamoex** » Thu Aug 25, 2016 8:53 pm

I'm going to further emphasize the question: how do you send CCs greater than 127? I'm not your MIDI doctor, but in 20 years I've never heard of CCs over 127. Exotic!

OpAmp · Post by **OpAmp** » Thu Aug 25, 2016 10:25 pm

Hi,

It is obvious that you can not program values larger than 127 for MIDI CC messages. That is not allowed by the standard.

The Samson Graphite hower allows you to do that?! A quick look in the manual reveals what is going on. They consider real MIDI CC messages (0-127), System Real Time messages and some standardized SysEx messages as (Samson Graphite) CC message. That way they come up with up to 180 CC types!

It is kind of confusing of course, but my bet is that when configured, the keyboard sends the standard System Real Time MIDI messages, which are only 1 byte long:
SG25 MIDI CC 148 - Start -> Real MIDI data: 0xFA
SG25 MIDI CC 149 - Continue -> Real MIDI data: 0xFB
SG25 MIDI CC 150 - Stop -> Real MIDI data: 0xFC

The MIDI implementation chart for the Volca Keys tells me that it supports the receive of these System Real Time MIDI messages...

Have fun.

Spheric El · Post by **Spheric El** » Fri Aug 26, 2016 1:46 pm

That's great OpAmp.Well cleared up.

billyjoker · Post by **billyjoker** » Mon Sep 05, 2016 9:38 am

It is kind of confusing of course, but my bet is that when configured, the keyboard sends the standard System Real Time MIDI messages, which are only 1 byte long:
SG25 MIDI CC 148 - Start -> Real MIDI data: 0xFA
SG25 MIDI CC 149 - Continue -> Real MIDI data: 0xFB
SG25 MIDI CC 150 - Stop -> Real MIDI data: 0xFC

Uhm... 0xFC is not 150... it is -4. 1 byte represent positive and negative range from -128 to 127... If you want represent 150 with unsigned byte (from 0 to 255) i think that as a hexadecimal value it would be 0x96, what do you think about it ?

OpAmp · Post by **OpAmp** » Mon Sep 05, 2016 9:23 pm

Hi Billyjoker,

You did not get my point. In the official MIDI spec, CC (controller change) messages range from 0 to 127. So higher CCs simply do not exist or can not be supported by MIDI. However the Samson Graphite presents other MIDI message (different from the CC ones) as CC with numbers higher than 127.

What happens actually is that, when on the Samson CC 150 is chosen, it will in fact send the official MIDI real time message 'Stop'. That message consists of 1 single byte, being 0xFC and has nothing to do at all with the 150 that Samson has (arbitrarily) chosen to represent the 'Stop'. Note also that an official MIDI CC message consists of 3 bytes...

Have fun.

Warning! Read this only if you are a programmer and/or into nerdy stuff, else forget the next part

* 0xFC = -4 if it is a signed byte, = 252 if it is an unsigned byte.
* 150 is indeed represented as 0x96 if it is an unsigned byte. 150 can not be represented by a signed byte (because the range is -128 - 127. You will need more than 1 byte (e.g. 16 bits)
* 0x96 sent over a Midi cable would mean: Note on on MIDI channel 7, two more bytes with values ranging from 0 - 127 needs to follow to indicate respectively the note and velocity.
* On a MIDI cable, bytes that have their most significant bit set to 1, represent the start of a MIDI message followed by 0 or more bytes with values between 0 and 127 (so that their most significant bit is 0).

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