if you don't have the parts for ADC try this

[MichaelPNolan]

The ADC module uses an analogue multipler to rotate through 8 knobs as an extension. This is only 8 of many parameters to control the basic synth. I'm just at the point now where I'm actually playing it.

I figured out whats going on enough to control parameters on a based ESP32 dev 1 board using a single POT wired between gnd/3.3v and 2 buttons for parameter switching. I might get it to dump parameters to screen so I can create a file of patches to save time.

Basically i created a bit of a noise filters so it doesn't make too many update calls. Only when you turn the 100k pot. Does a very slight oversample - nothing like Marcel's one in the adc_module.ino

I'm putting a bunch of physical button, pot handlers like this in the ADC as an alternative test harness until I get my midi control and start making some kind of map.

I think next I'll map one button to rotate through the wave forms. It takes time to get to know Marcel's code and I'm a rusty coder but I'm getting there.

Basically I'll have to fork the project but waiting until its updated before I do that. I never forked anyting on github ... so that will be a first for me. I don't really want to fork but ... i want people to be able to use this or document how it works for people learning. I'm just glad this exists and is shared at all.

bool  AdcSimple(){
    unsigned long int pinValue = 0;
    float delta, error;
    bool midiMsg = false;
    
    //for(int i=0; i < 100; i++) //oversample
          pinValue += analogRead(34);
          pinValue += analogRead(34);
          pinValue += analogRead(34);
          pinValue += analogRead(34);
          pinValue += analogRead(34);
          pinValue += analogRead(34);
    pinValue = pinValue / 6;
    adcSingle = float(pinValue)/4096.0f; //(pinValue/10)*10
    delta = adcSingleAve - adcSingle; //floating point absolute get rid of signed
    error = 0.009f+(0.012f*(adcSingle+0.1));  //previous weird idea error = 0.03*((adcSingle+0.25)*0.75); 
    
    
    if (fabs(delta) > error ){
       if(adcSetpoint != adcSingleAve) 
        {
          adcSetpoint = adcSingleAve;  //this line is not right - still working out this bit duh
                                                          //
          Serial.println("ADC read: " + String(adcSetpoint));
          adcChannelValue[analogueParamSet] = adcSetpoint;
          Synth_SetParam(analogueParamSet, adcChannelValue[analogueParamSet]);
          midiMsg = true;
          return 1;
        } 
      
      
    } else {
      
      return 0;
    }
    adcSingleAve = (adcSingleAve+adcSingle)/2;
/*
    if (midiMsg)
    {
        uint32_t midiValueU7 = (adcChannelValue[analogueParamSet] * 127.999);
        if (analogueParamSet < ADC_TO_MIDI_LOOKUP_SIZE)
        {
            #ifdef ADC_INVERT
            uint8_t idx = (ADC_INPUTS - 1) -analogueParamSet;
            #else
            uint8_t idx = analogueParamSet;
            #endif
            if (lastSendVal[idx] != midiValueU7)
            {
                Midi_ControlChange(adcToMidiLookUp[idx].ch, adcToMidiLookUp[idx].cc, midiValueU7);
                lastSendVal[idx] = midiValueU7;
            }
        }
    } */
}


void setupButtons(){
  pinMode(upButton, INPUT_PULLUP);  //pinMode(2, INPUT_PULLUP);
  pinMode(downButton, INPUT_PULLUP);

}

void processButtons(){ //some copied and modded debounce

  // read the state of the switch into a local variable:
  int readUpButton = digitalRead(upButton);
  int readDownButton = digitalRead(downButton);
  // check to see if you just pressed the button
  // (i.e. the input went from LOW to HIGH), and you've waited long enough
  // since the last press to ignore any noise:

  // If the switch changed, due to noise or pressing:
  if (readUpButton != lastUpButtonState) {
    // reset the debouncing timer
    lastUBDebounceTime = millis();
  }
   if (readDownButton != lastDownButtonState) {
    // reset the debouncing timer
    lastDBDebounceTime = millis();
  }

  if ((millis() - lastUBDebounceTime) > debounceDelay) {

    // if the button state has changed:
    if (readUpButton != upButtonState) {
      upButtonState = readUpButton;

      // only toggle the LED if the new button state is HIGH
      if (upButtonState == HIGH) {
         analogueParamSet++;
         if (analogueParamSet > 7) analogueParamSet=0;
         Serial.println("ParamSet: "+ String(analogueParamSet));
      }
    }
  }
  if ((millis() - lastUBDebounceTime) > debounceDelay) {

    // if the button state has changed:
    if (readDownButton != downButtonState) {
      downButtonState = readDownButton;

      // only toggle the LED if the new button state is HIGH
      if (upButtonState == HIGH) {
         analogueParamSet--;
         if (analogueParamSet < 0) analogueParamSet=7;
         Serial.println("ParamSet: "+ String(analogueParamSet));
      }
    }
  }
    // save the reading. Next time through the loop, it'll be the lastButtonState:
  lastUpButtonState = readUpButton;
  lastDownButtonState = readDownButton;

}

[marcel-licence]

Thank you for sharing =) My intention is to give just a basic playground which can be modified by your needs. I've commited one update 2 days ago regarding the USB MIDI implementation. The other update using the screen will appear in the sampler project first. I try to keep it modular so you you can put different parts together.

[MichaelPNolan]

Ok - that modular approach is excellent and I hope that as I play and learn my efforts can just be shared in case others come here. So I'm just trying to make friends and enrich your discussion here. So this was like my adaptation of a control surface - will be good to map to midi like yours is as I figure it out more. Could be a #define BUTTON_WITH_POT set of code just like you have other code paramaters for debug/setup.