RK-002 throttling message frequency

Loz

Hey,
I've got a DUY I wrote which translates CC to SysEx for my MKS-80, but find if I do filter sweeps, the amount of SysEx messages being send out flood the MIDI channel, and then cause a backlog, slowing down the note messages.

I wondered if there is a way anyone can think of of putting in a waittime or somesuch into the loop so that it only triggers 1 SysEx message every 10th of a second or so?

I tried using millis() command like this, but it doesn't seem to make any difference (I've even tried very last numbers, so think it's ignoring it)

long miditimer = millis();
bool RK002_onControlChange(byte channel, byte ccnumber, byte ccvalue)
{
   if (millis() - miditimer >= 100)
   {
        sendRolandSyx(1,ccnumber,ccvalue);
        return false;
      miditimer = millis();
      return true;
   }
}

Any ideas what I might be doing wrong?

Thanks in advance!

grit

The onControlChange is handled as fast as possible so trimming it down with a timer there will probably not give the desired results, maybe something like this would;

Keep track of the CC, put it in a variable and check changes on the timed loop. Only if there is a change, send it out. (i'm just putting this down without testing but I hope you see the method of thinning out the data):

long miditimer = millis();
byte oldCC=128; // non midi existent init value
byte newCC=128; // non midi existent init value (or comparison)
byte ccnumber=1;

void sendRolandSyx(byte id, byte num, byte ccnum)
{
 // the function you have
}
// called by RK002 on incoming controlchange midi:
bool RK002_onControlChange(byte channel, byte ccnumber, byte ccvalue)
{
  bool retval=true; // true/false flag used for forwarding original cc message
  if(channel==0){ // match midi channel 1
    if(ccnumber==1){ // match midi controller 1
      // yes: we will modify this, gets picked up in our timed sysex loop
      newCC=ccnumber; // this is the new value to compare with
      retval=false; // block original cc (saves Roland handling too)
    }
  }
  return retval; // forward original incoming cc yes/no
}


void loop(){
  if (millis() - miditimer >= 100){ // change this value if you want to poll less often
    if(newCC!=oldCC){ // did something happen on the controller?
      // yes: change -> send it as sysex
      sendRolandSyx(1,ccnumber,newCC);
      oldCC=newCC; // values handled
      miditimer = millis();
    }
  }
}

Loz

Hey - that's an interesting approach!

It'll give it a go later and let you know how I get on.

Loz

I had to play around a little bit as it didn't work exactly, but it is working now. I noticed that (possibly a typo in your code?) that it was passing the ccnumber and not the ccvalue. But then also found that the ccnumber wasn't being passed out of the RK002_onControlChange loop, so added a variable to pass this out (I'm also addressing two different partials depending on MIDI channel) and now with my additions everything seems to work great.

byte partial = 0; // upper or lower layer
byte sendccnumber = 1; // cc to send via sysex
byte oldCC=128; // non midi existent init value
byte newCC=128; // non midi existent init value (or comparison)
long miditimer = millis();

bool RK002_onControlChange(byte channel, byte ccnumber, byte ccvalue)
{
    bool retval=true;
      if ((channel==4) and (ccnumber>68) and (ccnumber<89)) // midi channel 5, controller within range?
      { 
		newCC=ccvalue; // this is the new value to compare with
        partial=0; // layer
        sendccnumber=ccnumber; // set send cc
		retval=false; // block original cc (saves Roland handling too)
      }
      if ((channel==5) and (ccnumber>68) and (ccnumber<89)) // midi channel 6, controller within range?
      { 
		newCC=ccvalue; // this is the new value to compare with
        partial=1; // layer
        sendccnumber=ccnumber; // set send cc
		retval=false; // block original cc (saves Roland handling too)
      }
      return retval;
}

void loop(){
  if (millis() - miditimer >= 50){ // change this value if you want to poll less often
    if(newCC!=oldCC){ // did something happen on the controller?
      // yes: change -> send it as sysex
      sendRolandSyx(partial,sendccnumber,newCC);
      // RK002_sendControlChange(0,sendccnumber,newCC); // check output is correct?
      oldCC=newCC; // values handled
      miditimer = millis();
    }
  }
}

Not sure if this is messy code or not (possibly as I don't know what I'm doing) but it's good enough for me.

Thanks for your help on this, and I am also massively indebted to the D50 CC-to-Sysex you wrote, which this is totally bastardised from.

grit

sorry about that, I did not test it on an actual setup but I'm glad it resulted into something you could work with 🙂

Loz

grit No worries at all! You definitely pushed me right into the correct direction.

Couldn't have sorted this without you. Thanks!