Connecting AI-Thinker ESP32-cam to Adafruit PCA9685 servo controller board

Question

I am new to Arduino and Esp32 programming. I need to connect PCA9685 controller to ESP-32 cam to be able to control multiple servo motors but the SCL and SDA pins are occupied by the UART control board.

I searched for this and found something related to Wire.h library and wire.begin() and TwoWire but unable to implement it.

#include <Wire.h>
#include <Adafruit_PWMServoDriver.h>

// called this way, it uses the default address 0x40
Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();


#define SERVOMIN  150 // This is the 'minimum' pulse length count (out of 4096)
#define SERVOMAX  600 // This is the 'maximum' pulse length count (out of 4096)
#define USMIN  600 // This is the rounded 'minimum' microsecond length based on the minimum pulse of 150
#define USMAX  2400 // This is the rounded 'maximum' microsecond length based on the maximum pulse of 600
#define SERVO_FREQ 50 // Analog servos run at ~50 Hz updates

// our servo # counter
uint8_t servonum = 0;

void setup() {
 Wire.begin();
  Wire.begin(2,15,100000); // this is to map new SCL and SDA pins to 2,15 
  Serial.begin(9600);
  Serial.println("8 channel Servo test!");

  pwm.begin();
  
  pwm.setOscillatorFrequency(27000000);
  pwm.setPWMFreq(SERVO_FREQ);  // Analog servos run at ~50 Hz updates

  delay(10);
}

// You can use this function if you'd like to set the pulse length in seconds
// e.g. setServoPulse(0, 0.001) is a ~1 millisecond pulse width. It's not precise!
void setServoPulse(uint8_t n, double pulse) {
  double pulselength;
  
  pulselength = 1000000;   // 1,000,000 us per second
  pulselength /= SERVO_FREQ;   // Analog servos run at ~60 Hz updates
  Serial.print(pulselength); Serial.println(" us per period"); 
  pulselength /= 4096;  // 12 bits of resolution
  Serial.print(pulselength); Serial.println(" us per bit"); 
  pulse *= 1000000;  // convert input seconds to us
  pulse /= pulselength;
  Serial.println(pulse);
  pwm.setPWM(n, 0, pulse);
}

void loop() {
   pwm.setPWM(0, 0, 250);
  
}

Here is the test code that I am trying to run. I got the implementation idea from https://randomnerdtutorials.com/esp32-i2c-communication-arduino-ide/

There are a few problems that I encounter along with no response from the code-

1. When PCA9685 is connected to esp32-cam and I try to upload the code, it doesn't work and gives fatal error.
2. When the reset button is pressed before upload the built-in flash blinks. This is presented as a problem because while trying to upload the code without PCA9685 attached, the code is uploaded without any fatal error and there is no 'flash blink'.
3. I tried a code from the same website mentioned above that looks for I2C devices and prints their address. It shows no devices even though the servo controller is connected to it.

PS- I am an absolute beginner in this field.