Random midi CC

[djPtrvch]

Hello! I want to make a midi controller with 64 potentiometers for iPad. I use Arduino pro micro and 4 multiplexers cd74hc4067.
My code.

// Array of mux
CD74HC4067 muxes[] = {
{
  A0,
   {0, 1, 2, 3},
},
{
  A1,
   {0, 1, 2, 3},
},
 {
   A2,
   {0, 1, 2, 3},
},
 {
   A3,
   {0, 1, 2, 3},
}
};

// Array of pots
CCPotentiometer potentiometers[] = {
    { muxes[0].pin(0), { 0, CHANNEL_13 } },
    { muxes[0].pin(1), { 1, CHANNEL_13 } },
    { muxes[0].pin(2), { 2, CHANNEL_13 } },
    { muxes[0].pin(3), { 3, CHANNEL_13 } },
    { muxes[0].pin(4), { 4, CHANNEL_13 } },
    { muxes[0].pin(5), { 5, CHANNEL_13 } },
    { muxes[0].pin(6), { 6, CHANNEL_13 } },
    { muxes[0].pin(7), { 7, CHANNEL_13 } },
    { muxes[0].pin(8), { 8, CHANNEL_13 } },
    { muxes[0].pin(9), { 9, CHANNEL_13 } },
    { muxes[0].pin(10), { 10, CHANNEL_13 } },
    { muxes[0].pin(11), { 11, CHANNEL_13 } },
    { muxes[0].pin(12), { 12, CHANNEL_13 } },
    { muxes[0].pin(13), { 13, CHANNEL_13 } },
    { muxes[0].pin(14), { 14, CHANNEL_13 } },
    { muxes[0].pin(15), { 15, CHANNEL_13 } },
 

    { muxes[1].pin(0), { 16, CHANNEL_13 } },
    { muxes[1].pin(1), { 17, CHANNEL_13 } },
    { muxes[1].pin(2), { 18, CHANNEL_13 } },
    { muxes[1].pin(3), { 19, CHANNEL_13 } },
    { muxes[1].pin(4), { 20, CHANNEL_13 } },
    { muxes[1].pin(5), { 21, CHANNEL_13 } },
    { muxes[1].pin(6), { 22, CHANNEL_13 } },
    { muxes[1].pin(7), { 23, CHANNEL_13 } },
    { muxes[1].pin(8), { 24, CHANNEL_13 } },
    { muxes[1].pin(9), { 25, CHANNEL_13 } },
    { muxes[1].pin(10), { 26, CHANNEL_13 } },
    { muxes[1].pin(11), { 27, CHANNEL_13 } },
    { muxes[1].pin(12), { 28, CHANNEL_13 } },
    { muxes[1].pin(13), { 29, CHANNEL_13 } },
    { muxes[1].pin(14), { 30, CHANNEL_13 } },
    { muxes[1].pin(15), { 31, CHANNEL_13 } },

    { muxes[2].pin(0), { 32, CHANNEL_13 } },
    { muxes[2].pin(1), { 33, CHANNEL_13 } },
    { muxes[2].pin(2), { 34, CHANNEL_13 } },
    { muxes[2].pin(3), { 35, CHANNEL_13 } },
    { muxes[2].pin(4), { 36, CHANNEL_13 } },
    { muxes[2].pin(5), { 37, CHANNEL_13 } },
    { muxes[2].pin(6), { 38, CHANNEL_13 } },
    { muxes[2].pin(7), { 39, CHANNEL_13 } },
    { muxes[2].pin(8), { 40, CHANNEL_13 } },
    { muxes[2].pin(9), { 41, CHANNEL_13 } },
    { muxes[2].pin(10), { 42, CHANNEL_13 } },
    { muxes[2].pin(11), { 43, CHANNEL_13 } },
    { muxes[2].pin(12), { 44, CHANNEL_13 } },
    { muxes[2].pin(13), { 45, CHANNEL_13 } },
    { muxes[2].pin(14), { 46, CHANNEL_13 } },
    { muxes[2].pin(15), { 47, CHANNEL_13 } },

    { muxes[3].pin(0), { 48, CHANNEL_13 } },
    { muxes[3].pin(1), { 49, CHANNEL_13 } },
    { muxes[3].pin(2), { 50, CHANNEL_13 } },
    { muxes[3].pin(3), { 51, CHANNEL_13 } },
    { muxes[3].pin(4), { 52, CHANNEL_13 } },
    { muxes[3].pin(5), { 53, CHANNEL_13 } },
    { muxes[3].pin(6), { 54, CHANNEL_13 } },
    { muxes[3].pin(7), { 55, CHANNEL_13 } },
    { muxes[3].pin(8), { 56, CHANNEL_13 } },
    { muxes[3].pin(9), { 57, CHANNEL_13 } },
    { muxes[3].pin(10), { 58, CHANNEL_13 } },
    { muxes[3].pin(11), { 59, CHANNEL_13 } },
    { muxes[3].pin(12), { 60, CHANNEL_13 } },
    { muxes[3].pin(13), { 61, CHANNEL_13 } },
    { muxes[3].pin(14), { 62, CHANNEL_13 } },
    { muxes[3].pin(15), { 63, CHANNEL_13 } },
};

When connected to iPad, Arduino sends a whole series of random midi CC. Tell me if I have an error in the code or somewhere else? In the test version, I only connected one multiplexer and a potentiometer to Arduino.

[tttapa]

In the test version, I only connected one multiplexer and a potentiometer to Arduino.

It sounds like most of the inputs are floating, so they'll be picking up random noise. Your code should only contain potentiometers and muxes that are actually connected.

[djPtrvch]

I tried connecting one mux and four potentiometers. // Array of mux
CD74HC4067 muxes[] = {
{
A0,
{0, 1, 2, 3},
}
};

// Array of pots
CCPotentiometer potentiometers[] = {
{ muxes[0].pin(0), { 0, CHANNEL_13 } },
{ muxes[0].pin(1), { 1, CHANNEL_13 } },
{ muxes[0].pin(2), { 2, CHANNEL_13 } },
{ muxes[0].pin(3), { 3, CHANNEL_13 } },

};

But when mapping to iPad CC messages continue to change randomly

[djPtrvch]

In the test version, I only connected one multiplexer and a potentiometer to Arduino.

It sounds like most of the inputs are floating, so they'll be picking up random noise. Your code should only contain potentiometers and muxes that are actually connected.

Please tell me where the error might be

[djPtrvch]

[tttapa]

It looks like you posted the reply before the image upload was complete.

[djPtrvch]

Apparently yes. Re-uploaded.

[djPtrvch]

[tttapa]

Please post your full code. The MIDI messages shown here cannot have originated from the code you posted in #1082 (reply in thread) (e.g. the channels are all wrong).

[djPtrvch]

/**

• This example demonstrates the use of MIDI Control Change potentiometers that
• can be used for changing effect parameters, volumes, pan and balance
• controls, etc. It can control almost any knob in your DAW software.
• This example shows how to define multiple potentiometers using an array.
• @boards AVR, AVR USB, Nano Every, Due, Nano 33 IoT, Nano 33 BLE, UNO R4, Teensy 3.x
• Connections

• ---

• • A0: wiper of the first potentiometer
• • A1: wiper of the second potentiometer
• • ...
• • A5: wiper of the sixth potentiometer
• Connect the left terminal of the potentiometers to ground, and the right one
• to V_CC.
• Behavior

• ---

• • When you turn a potentiometer, you should receive MIDI Control Change
• events, with a value between 0 and 127.
• • The analog inputs are filtered, so there shouldn't be any noise on the
• position. If there is, check your wiring, and make sure that the resistance
• of the potentiometers isn't too high (10 kΩ is ideal).
• Mapping

• ---

• Select the Arduino as a custom MIDI controller in your DAW, and use the
• MIDI learn option to assign the potentiometers to a function.
• Written by PieterP, 2019-08-13
• https://github.com/tttapa/Control-Surface
  */

#include <Control_Surface.h> // Include the Control Surface library

// Instantiate a MIDI over USB interface.
USBMIDI_Interface midi;

// Array of mux
CD74HC4067 muxes[] = {
{
A0,
{0, 1, 2, 3},
}
};

// Array of pots
CCPotentiometer potentiometers[] = {
{ muxes[0].pin(0), { 0, CHANNEL_13 } },
{ muxes[0].pin(1), { 1, CHANNEL_13 } },
{ muxes[0].pin(2), { 2, CHANNEL_13 } },
{ muxes[0].pin(3), { 3, CHANNEL_13 } },

};

void setup() {
Control_Surface.begin(); // Initialize Control Surface
}

void loop() {
Control_Surface.loop(); // Update the Control Surface
}

[djPtrvch]

Could this be a problem with the Arduino board itself?

[djPtrvch]

I tried connecting potentiometers to Arduino without a multiplexer, same thing

[djPtrvch]

@tttapa Please tell me where the error might be

[LukeThomasDawson]

A couple of things to try:
(1) For every input that you define, make sure it actually has a valid input physically connected to the corresponding pin. So if you define 4 CCPotentiometers, make sure you have 4 pots connected up to those pins so that none of the pins are left "floating"
(2) Try creating just one CCPotentiometer and connecting one physical pot up to that pin. Then do the same thing but specify a different pin. Then you can test your setup one pin/function at a time.

[djPtrvch]

A couple of things to try: (1) For every input that you define, make sure it actually has a valid input physically connected to the corresponding pin. So if you define 4 CCPotentiometers, make sure you have 4 pots connected up to those pins so that none of the pins are left "floating" (2) Try creating just one CCPotentiometer and connecting one physical pot up to that pin. Then do the same thing but specify a different pin. Then you can test your setup one pin/function at a time.

I did as you advised and connected one potentiometer separately to each output. Everything works. But as soon as I connected 4 potentiometers to 4 analog outputs, the CC values began to jump.

[tttapa]

What's the resistance of your potentiometers? If it's too large, you get cross-talk between ADC channels.

[djPtrvch]

What's the resistance of your potentiometers? If it's too large, you get cross-talk between ADC channels.

10kOm