Help a newbie with some code?

[pilotguy9853]

I have two sets of code.

One set reads a bunch of push button switches and rotary encoders and uses the Tiny USB library to pass this along to the Windows game controller. This works fine.

The second set of code reads a pushbutton on a MCP-23017 (I need more input pins than the ESP-32 S3 board has). This code works fine.

When I combine the two sets of code however, it will not seem to read the MCP-23017 at all. There are two settings that I have to change in the Arduino IDE to get the Tiny USB part of the code to work. USB CDC on Boot > Enabled and USB Mode: USB-OTG (Tiny USB). I am not sure of one or both of these settings causes the MCP-23017 to not work but as I said, independently both sets of code work fine but combined the MCP-23017 is not working.

Any help you can give would be greatly appreciated.

COMBINED SETS OF CODE:

#include <Wire.h>
#include <Adafruit_MCP23X17.h>

#ifndef ARDUINO_USB_MODE
#elif ARDUINO_USB_MODE == 1
#else

#include "USB.h"
#include "USBHIDGamepad.h"

USBHIDGamepad Gamepad;

// --------------------- MCP23017 SETUP ---------------------
Adafruit_MCP23X17 mcp;
#define I2C_SDA 20
#define I2C_SCL 19
#define MCP_BUTTON_PIN 0 // MCP23017 pin PA0
const uint8_t MCP_GAMEPAD_BUTTON = 29; // Custom gamepad button for MCP button (adjust as needed)
bool lastMCPButtonState = true;

// --------------------- BUTTONS SETUP ----------------------
const int numButtons = 17;
const int buttonPins[numButtons] = {6, 16, 46, 11, 14, 1, 2, 42, 41, 40, 39, 38, 37, 36, 35, 0, 45};
int buttonLastState[numButtons] = {HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH};
const uint8_t buttonGamepadNumbers[numButtons] = {2, 5, 10, 13, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28};

// ------------------- ENCODERS SETUP -----------------------
const int numEncoders = 6;
const int encoderPins[numEncoders][2] = {
{4, 5}, {7, 15}, {17, 18}, {8, 3}, {9, 10}, {12, 13}
};
const uint8_t encoderCWButtons[numEncoders] = {0, 3, 6, 8, 11, 14};
const uint8_t encoderCCWButtons[numEncoders] = {1, 4, 7, 9, 12, 15};
int lastEncoded[numEncoders] = {0};
int encoderSteps[numEncoders] = {0};
const int debounceSteps = 4;

void setup() {
Serial.begin(115200);
delay(1000);

// ---------- Initialize USB Gamepad ----------
Gamepad.begin();
USB.begin();

// ---------- Set up physical buttons ----------
for (int i = 0; i < numButtons; i++) {
pinMode(buttonPins, INPUT_PULLUP);
}

// ---------- Set up rotary encoders ----------
for (int i = 0; i < numEncoders; i++) {
pinMode(encoderPins[0], INPUT_PULLUP);
pinMode(encoderPins[1], INPUT_PULLUP);
int MSB = digitalRead(encoderPins[0]);
int LSB = digitalRead(encoderPins[1]);
lastEncoded = (MSB << 1) | LSB;
}

// ---------- Set up MCP23017 ----------
Wire.begin(I2C_SDA, I2C_SCL);
if (!mcp.begin_I2C(0x27, &Wire)) {
Serial.println("MCP23017 not found. Check wiring.");
while (1);
}
Serial.println("MCP23017 initialized.");
mcp.pinMode(MCP_BUTTON_PIN, INPUT_PULLUP);

Serial.println("Setup complete.");
}

void loop() {
// ---------- Handle physical buttons ----------
for (int i = 0; i < numButtons; i++) {
int currentState = digitalRead(buttonPins);
if (currentState != buttonLastState) {
if (currentState == LOW) {
Gamepad.pressButton(buttonGamepadNumbers);
} else {
Gamepad.releaseButton(buttonGamepadNumbers);
}
buttonLastState[i] = currentState;
}
}

// ---------- Handle rotary encoders ----------
for (int i = 0; i < numEncoders; i++) {
int MSB = digitalRead(encoderPins[i][0]);
int LSB = digitalRead(encoderPins[i][1]);
int encoded = (MSB << 1) | LSB;
int sum = (lastEncoded[i] << 2) | encoded;

switch (sum) {
case 0b1101: case 0b0100: case 0b0010: case 0b1011:
encoderSteps[i]++;
break;
case 0b1110: case 0b0111: case 0b0001: case 0b1000:
encoderSteps[i]--;
break;
}

lastEncoded[i] = encoded;

if (encoderSteps[i] >= debounceSteps) {
Gamepad.pressButton(encoderCWButtons[i]);
delay(100);
Gamepad.releaseButton(encoderCWButtons[i]);
encoderSteps[i] = 0;
} else if (encoderSteps[i] <= -debounceSteps) {
Gamepad.pressButton(encoderCCWButtons[i]);
delay(100);
Gamepad.releaseButton(encoderCCWButtons[i]);
encoderSteps[i] = 0;
}
}

// ---------- Handle MCP23017 button ----------
bool currentMCPButtonState = mcp.digitalRead(MCP_BUTTON_PIN);
if (currentMCPButtonState != lastMCPButtonState) {
if (currentMCPButtonState == LOW) {
Serial.println("MCP23017 button pressed.");
Gamepad.pressButton(MCP_GAMEPAD_BUTTON);
} else {
Gamepad.releaseButton(MCP_GAMEPAD_BUTTON);
}
lastMCPButtonState = currentMCPButtonState;
delay(50); // Simple debounce
}
}

#endif /* ARDUINO_USB_MODE */