ArduinoFFT library argument list compilation error in Arduino

Question

I am creating a sound visualizer using an arduino nano,electret condenser microphone and 8X32 matrix and i keep getting the same error.

here is the code:

#include <ArduinoFFT.h>
#include <Adafruit_GFX.h>
#include <Adafruit_NeoMatrix.h>
#include <Adafruit_NeoPixel.h>
#define PIN_MATRIX 2 // Arduino Nano Pin D2 to DIN of matrix
#define PIN_MIC 0 // Arduino Nano Analog Pin A0 to microphone Vout
#define MATRIX_WIDTH 32
#define MATRIX_HEIGHT 8
#define MIC_SAMPLE_SIZE 48 // Change according to your mic module's specifications
ArduinoFFT fft;
Adafruit_NeoMatrix matrix = Adafruit_NeoMatrix(MATRIX_WIDTH, MATRIX_HEIGHT, PIN_MATRIX,
 NEO_MATRIX_TOP + NEO_MATRIX_LEFT +
 NEO_MATRIX_COLUMNS + NEO_MATRIX_ZIGZAG,
 NEO_GRB + NEO_KHZ800);
void setup() {
 Serial.begin(9600);
 matrix.begin();
 matrix.setTextWrap(false);
 matrix.setBrightness(50); // Adjust brightness as needed
 matrix.setTextColor(matrix.Color(255, 255, 255)); // Text color
 fft.begin(MIC_SAMPLE_SIZE); // Initialize the FFT object
}
void loop() {
 fft.Execute(); // Run FFT
 int max_index = 0;
 int max_value = 0;
 for (int i = 0; i < MIC_SAMPLE_SIZE / 2; i++) {
 int value = fft.Output[i]; // Read FFT result
 if (value > max_value) {
 max_value = value;
 max_index = i;
 }
 }
 // Map max_index to matrix columns
 int column = map(max_index, 0, MIC_SAMPLE_SIZE / 2, 0, MATRIX_WIDTH);
 // Clear matrix
 matrix.fillScreen(0);
 // Draw bar on matrix
 for (int y = 0; y < MATRIX_HEIGHT; y++) {
 matrix.drawPixel(column, y, matrix.Color(255, 255, 255)); // White color
 }
 matrix.show();
}

Here is the error:

/Users/vyomesh/Documents/Arduino/sketch_apr22a/sketch_apr22a.ino:12:1: error: invalid use of template-name 'ArduinoFFT' without an argument list
 ArduinoFFT fft;
 ^~~~~~~~~~
/Users/vyomesh/Documents/Arduino/sketch_apr22a/sketch_apr22a.ino:12:1: note: class template argument deduction is only available with -std=c++1z or -std=gnu++1z
In file included from /Users/vyomesh/Documents/Arduino/sketch_apr22a/sketch_apr22a.ino:1:0:
/Users/vyomesh/Documents/Arduino/libraries/arduinoFFT/src/ArduinoFFT.h:58:29: note: 'template<class T> class ArduinoFFT' declared here
 template <typename T> class ArduinoFFT {
 ^~~~~~~~~~
/Users/vyomesh/Documents/Arduino/sketch_apr22a/sketch_apr22a.ino: In function 'void setup()':
/Users/vyomesh/Documents/Arduino/sketch_apr22a/sketch_apr22a.ino:25:3: error: 'fft' was not declared in this scope
 fft.begin(MIC_SAMPLE_SIZE); // Initialize the FFT object
 ^~~
/Users/vyomesh/Documents/Arduino/sketch_apr22a/sketch_apr22a.ino:25:3: note: suggested alternative: 'ffs'
 fft.begin(MIC_SAMPLE_SIZE); // Initialize the FFT object
 ^~~
 ffs
/Users/vyomesh/Documents/Arduino/sketch_apr22a/sketch_apr22a.ino: In function 'void loop()':
/Users/vyomesh/Documents/Arduino/sketch_apr22a/sketch_apr22a.ino:29:3: error: 'fft' was not declared in this scope
 fft.Execute(); // Run FFT
 ^~~
/Users/vyomesh/Documents/Arduino/sketch_apr22a/sketch_apr22a.ino:29:3: note: suggested alternative: 'ffs'
 fft.Execute(); // Run FFT
 ^~~
 ffs
exit status 1
Compilation error: invalid use of template-name 'ArduinoFFT' without an argument list

Matrix Wiring: GND-GND 5V-5V DIN-D2

Electret condenser michrophone: Positive- A0 and connected to 5V through resistor Negative- GND

Other info: Macos sonoma library name- ArduinoFFT.h

• Restarted IDE
• Reinstalled the library
• tried different versions
• sought help from ChatGPT as a last resort (still failed)

Answer 1

This is a build-related issue. It has nothing to do with your electronic design ..

According to the GitHub page of the project, you are expected to provide some parameters to the constructor:

/*
These are the input and output vectors
Input vectors receive computed results from FFT
*/
double vReal[samples];
double vImag[samples];
ArduinoFFT<double> FFT = ArduinoFFT<double>(vReal, vImag, samples, samplingFrequency);

The above code is taken from the example file FFT_01.ino hosted on the project's GitHub page.