Slow Encoders For Midi Controller

[JoeD.]

Hi Im working on a midi controller I'm using the Teensy 4.1 with a mpc23s17 I currently have 8 encoders wired up to the mcp. When I turn the encoders I have to turn them almost a full rotation to get it to move one or two increments on the serial monitor. Anybody have any tips? Thanks in advance.

Here is the code I'm using


#include <Adafruit_MCP23X17.h>
#include <MIDI.h>
Adafruit_MCP23X17 mcp;
MIDI_CREATE_DEFAULT_INSTANCE();
const int MCP_CS_PIN = 10; // Chip select for SPI
const int NUM_ENCODERS = 8;
// Encoder state storage
uint8_t lastState[NUM_ENCODERS];
int encoderValues[NUM_ENCODERS] = {0};
// MIDI CC numbers for each encoder
const uint8_t midiCCs[NUM_ENCODERS] = {20, 21, 22, 23, 24, 25, 26, 27};
void setup() {
Serial.begin(115200);
MIDI.begin(MIDI_CHANNEL_OMNI);
if (!mcp.begin_SPI(MCP_CS_PIN)) {
Serial.println("Failed to initialize MCP23S17");
while (1);
}
// Setup encoder pins
for (int i = 0; i < NUM_ENCODERS; i++) {
int pinA = i * 2;
int pinB = i * 2 + 1;
mcp.pinMode(pinA, INPUT);
mcp.pinMode(pinB, INPUT);
mcp.digitalWrite(pinA, HIGH); // enable pull-ups
mcp.digitalWrite(pinB, HIGH);
// Read initial state
uint8_t a = mcp.digitalRead(pinA);
uint8_t b = mcp.digitalRead(pinB);
lastState = (a << 1) | b;
}
}
void loop() {
for (int i = 0; i < NUM_ENCODERS; i++) {
int pinA = i * 2;
int pinB = i * 2 + 1;
uint8_t a = mcp.digitalRead(pinA);
uint8_t b = mcp.digitalRead(pinB);
uint8_t state = (a << 1) | b;
if (state != lastState) {
int delta = getEncoderDelta(lastState, state);
if (delta != 0) {
encoderValues = constrain(encoderValues + delta, 0, 127);
MIDI.sendControlChange(midiCCs, encoderValues, 1);
Serial.print("Encoder ");
Serial.print(i);
Serial.print(": ");
Serial.println(encoderValues);
}
lastState = state;
}
}
}
int getEncoderDelta(uint8_t last, uint8_t current) {
// Basic gray-code to direction mapping
if ((last == 0b00 && current == 0b01) ||
(last == 0b01 && current == 0b11) ||
(last == 0b11 && current == 0b10) ||
(last == 0b10 && current == 0b00)) {
return 1;
}
if ((last == 0b00 && current == 0b10) ||
(last == 0b10 && current == 0b11) ||
(last == 0b11 && current == 0b01) ||
(last == 0b01 && current == 0b00)) {
return -1;
}
return 0;
}

 

[JoeD.]

Here is a photo. Sorry its hard to see what going on in this rats nest.

 

[joepasquariello]

When you post code, please use the </> button to keep the formatting.

I've never used the MCP23017 library, but I installed it and looked at the button (input) example. It uses the code shown below for enabling pull-ups. You are configuring your MCP pins as INPUT, then setting them HIGH via mcp.digitalWrite(), which probably converts them back to OUTPUT. Try using pinMode() as shown below, and remove those calls to digitalWrite() that you have labeled as "enable pull-ups"

  // configure pin for input with pull up
  mcp.pinMode(BUTTON_PIN, INPUT_PULLUP);