Old sketch won't run on Portenta C33

Hardware Portenta Portenta C33
1

Hello, I have a sketch that worked great on a UNO and a 1284 narrow, but when I try to upload it to the Portenta C33 it gives me lots of errors. please note that I did not write this code. I have modified it for my use, but I am providing the original code I used so that none of my bad coding practices are included.

Code:

/*
Example of use of the FFT libray on a "1284 Narrow" board
to compute the frequency spectrum over 1024 frequency bands
of a 440 Hz signal (amplitude near 5V), generated by a
signal generator and connected through a 1 KOhm resistor to A0.

It uses 51% of the 16 KB of RAM of the Atmega1284

Based on GitHub - kosme/arduinoFFT: Fast Fourier Transform for Arduino
Example adapated by Thierry Guennou / Pandauino.com

----------------------------

Copyright (C) 2014 Enrique Condes
Copyright (C) 2020 Bim Overbohm (header-only, template, speed improvements)

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "arduinoFFT.h"

// ****************************************************************************************************************
// DECLARATIONS

#define SCL_INDEX 0x00
#define SCL_TIME 0x01
#define SCL_FREQUENCY 0x02
#define SCL_PLOT 0x03
 
const byte adcPin = 0;                      // A0
const uint16_t samples = 1024;              // This value MUST ALWAYS be a power of 2
const uint16_t samplingFrequency = 8000;    // Will affect timer max value in timer_setup() SYSCLOCK/8/samplingFrequency should be a integer

/*
These are the input and output vectors
Input vectors receive computed results from FFT
*/
volatile int resultNumber;
float vReal[samples];
float vImag[samples];

// ****************************************************************************************************************
// INSTANTIATIONS

/* Create FFT object */
ArduinoFFT<float> FFT = ArduinoFFT<float>(vReal, vImag, samples, samplingFrequency);


// ****************************************************************************************************************
// INTERRUPTS

// ADC complete ISR
ISR (ADC_vect)
{
    vReal[resultNumber++] = ADC;
            
    if(resultNumber == samples)
    {
      ADCSRA = 0;  // turn off ADC
    }
} 

EMPTY_INTERRUPT (TIMER1_COMPB_vect);

// ****************************************************************************************************************
// FUNCTIONS

void timer_setup(){
  // reset Timer 1
  TCCR1A = 0;
  TCCR1B = 0;
  TCNT1 = 0;
  TCCR1B = bit (CS11) | bit (WGM12);  // CTC, prescaler of 8
  TIMSK1 = bit (OCIE1B);
  OCR1A = ((16000000 / 8) / samplingFrequency) -1;  // sampling frequency = 16/8/250 MHz =  8  KHz 
}

void adc_setup() {
  ADCSRA =  bit (ADEN) | bit (ADIE) | bit (ADIF);   // turn ADC on, want interrupt on completion
  ADCSRA |= bit (ADPS2);  // Prescaler of 16
  ADMUX = bit (REFS0) | (adcPin & 7);
  ADCSRB = bit (ADTS0) | bit (ADTS2);  // Timer/Counter1 Compare Match B trigger source
  ADCSRA |= bit (ADATE);   // turn on automatic triggering  
}

void zeroI() {
   for (uint16_t i = 0; i < samples; i++)
  {
    vImag[i] = 0.0; //Imaginary part must be zeroed in case of looping to avoid wrong calculations and overflows
  } 
}

void PrintVector(float *vData, uint16_t bufferSize, uint8_t scaleType)
{
  for (uint16_t i = 0; i < bufferSize; i++)
  {
    float abscissa;
    /* Print abscissa value */
    switch (scaleType)
    {
      case SCL_INDEX:
        abscissa = (i * 1.0);
  break;
      case SCL_TIME:
        abscissa = ((i * 1.0) / samplingFrequency);
  break;
      case SCL_FREQUENCY:
        abscissa = ((i * 1.0 * samplingFrequency) / samples);
  break;
    }
    Serial.print(abscissa, 6);
    if(scaleType==SCL_FREQUENCY)
      Serial.print("Hz");
    Serial.print(" ");
    Serial.println(vData[i], 4);
  }
  Serial.println();
}


// ****************************************************************************************************************
// SETUP

void setup()
{
  Serial.begin(115200);
  while(!Serial);
  Serial.println("Ready");

  zeroI(); // clears imaginary data
  timer_setup();
  adc_setup();
  
}

void loop()
{
  // waits until the array is full
  while (resultNumber < samples){ }

  /* Print the raw sampled data */
  //  Serial.println("Data:");
  //  PrintVector(vReal, samples, SCL_TIME);
  
  FFT.dcRemoval(); 
  FFT.windowing(FFTWindow::Hamming, FFTDirection::Forward);	// Weigh data
  FFT.compute(FFTDirection::Forward); // Compute FFT
  FFT.complexToMagnitude(); // Compute magnitudes 
  // printing the spectrum and the fundamental frequency f0
  PrintVector(vReal, (samples >> 1), SCL_FREQUENCY);
  float x = FFT.majorPeak();
  Serial.print("f0=");
  Serial.print(x, 6);
  Serial.println("Hz");

  resultNumber = 0; 

// ADC could be started again
/*  delay(1000);
  zeroI();
  adc_setup();
*/
 
}