tom321
January 4, 2021, 1:43pm
1
Hi
//https://github.com/Harvie/Programs/blob/master/c/goertzel/goertzel.c
#include <stdio.h>
#include <math.h>
//#include <getopt.h>
////////////////////////////////
int audioInPin = A0;
int audioOutPin = 8;
int ledPin = 13;
///////////////////////////////////////////
int i, k, n, q0, q1, q2, data;
int magnitude;
int floatnumSamples;
int omega = (2.0 * M_PI * k) / floatnumSamples;
int sine = sin(omega);
int cosine = cos(omega);
int coeff = 2.0 * cosine;
int imag;
int real ;
int scalingFactor;
int numSamples;
char code[20];
/////////////////////////////
float goertzel_mag(int numSamples, float TARGET_FREQUENCY, int SAMPLING_RATE, float* data)
{
int k, i;
float floatnumSamples;
float omega, sine, cosine, coeff, q0, q1, q2, magnitude, real, imag;
float scalingFactor = numSamples / 2.0;
floatnumSamples = (float) numSamples;
k = (int) (0.5 + ((floatnumSamples * TARGET_FREQUENCY) / (float)SAMPLING_RATE));
omega = (2.0 * M_PI * k) / floatnumSamples;
sine = sin(omega);
cosine = cos(omega);
coeff = 2.0 * cosine;
q0 = 0;
q1 = 0;
q2 = 0;
}
void setup() {
Serial.begin(115200);
}
//////////////////////////////////////////////
void loop() {
for (i = 0; i < n; i++)
{
data[i] = analogRead(audioInPin);
float q0;
q0 = coeff * q1 - q2 + (float) data[i];
q2 = q1;
q1 = q0;
}
// calculate the real and imaginary results
// scaling appropriately
real = (q1 * cosine - q2) / scalingFactor;
imag = (q1 * sine) / scalingFactor;
magnitude = sqrtf(real * real + imag * imag);
//phase = atan(imag/real)
return magnitude;
Serial.print(magnitude);
Serial.println();
}
error
sketch_jan02d:54:11: error: invalid types 'int[int]' for array subscript
data = analogRead(audioInPin);
^*sketch_jan02d:56:42: error: invalid types 'int[int]' for array subscript _ ^*_exit status 1 invalid types 'int[int]' for array subscript
By using the correct type as the compiler suggests. Now data is an int but you try to use it as an array.
int i, k, n, q0, q1, q2, data;
data[i] = analogRead(audioInPin);
oops.
tom321
January 4, 2021, 4:31pm
4
Thanks , no errors but on serial monitor is nothing, blank screen.
#include <stdio.h>
#include <math.h>
//#include <getopt.h>
const float TARGET_FREQUENCY = 1700;
int audioInPin = A0;
int k, i;
int goertzel_mag(int numSamples, float TARGET_FREQUENCY, int SAMPLING_RATE, float* data);
// float omega,sine,cosine,coeff,q0,q1,q2,magnitude,real,imag;
int q0, q1, q2, omega, sine, cosine, coeff, magnitude, real, imag;
float floatnumSamples;
int SAMPLING_RATE = 8900;
int numSamples;
float scalingFactor = numSamples / 2.0;
float* data;
//int q0 = 0;
//int q1 = 0;
//int q2 = 0;
void setup() {
k = (int) (0.5 + ((floatnumSamples * TARGET_FREQUENCY) / (float)SAMPLING_RATE));
omega = (2.0 * M_PI * k) / floatnumSamples;
sine = sin(omega);
cosine = cos(omega);
coeff = 2.0 * cosine;
Serial.begin(115200);
}
void loop() {
for (i = 0; i < numSamples; i++)
{
//testData[index] = analogRead(audioInPin);
data[i] = analogRead(audioInPin);
q0 = coeff * q1 - q2 + data[i];
q2 = q1;
q1 = q0;
}
// calculate the real and imaginary results
// scaling appropriately
real = (q1 * cosine - q2) / scalingFactor;
imag = (q1 * sine) / scalingFactor;
magnitude = sqrtf(real * real + imag * imag);
//phase = atan(imag/real)
return magnitude;
Serial.print(real);
Serial.print("\t");
Serial.print(imag);
Serial.print("\t");
Serial.println();
}
'data' still isn't an array... So now you're writing stuff in memory that's not allocated for the task.
Read up on array's
The printing code is after this:
return magnitude;
so it never happens.
How can you expect to print AFTER a return statement? In fact, I am surprised that this doesn't generate a warning or an error.
I am away from my computer right now or I would try this myself.
vaj4088:
Indeed. It doesn't though. I'll guess that whatever the default compiler flags the IDE uses supressed the warnings.
I would have expected something about unreachable code and value returned from void function, but I actually got no errors at all.
That was my expectation also. Interesting. Thanks !
tom321
January 4, 2021, 4:58pm
10
I removed - return magnitude;
I got zeroes rather than nan when I ran it without the return. Please post the adjusted code.
tom321
January 4, 2021, 5:31pm
13
3x nan
#include <stdio.h>
#include <math.h>
//#include <getopt.h>
const float TARGET_FREQUENCY = 1700;
int audioInPin = A0;
int k, i;
int goertzel_mag(int numSamples, float TARGET_FREQUENCY, int SAMPLING_RATE, float* data);
float omega, sine, cosine, coeff, q0, q1, q2, magnitude, real, imag;
//int q0, q1, q2, omega, sine, cosine, coeff, magnitude, real, imag;
float floatnumSamples;
int SAMPLING_RATE = 8900;
int numSamples;
float scalingFactor = numSamples / 2.0;
float* data;
//int q0 = 0;
//int q1 = 0;
//int q2 = 0;
void setup() {
k = (int) (0.5 + ((floatnumSamples * TARGET_FREQUENCY) / (float)SAMPLING_RATE));
omega = (2.0 * M_PI * k) / floatnumSamples;
sine = sin(omega);
cosine = cos(omega);
coeff = 2.0 * cosine;
Serial.begin(115200);
}
void loop() {
for (i = 0; i < numSamples; i++)
{
//testData[index] = analogRead(audioInPin);
data[i] = analogRead(audioInPin);
q0 = coeff * q1 - q2 + data[i];
q2 = q1;
q1 = q0;
}
// calculate the real and imaginary results
// scaling appropriately
real = (q1 * cosine - q2) / scalingFactor;
imag = (q1 * sine) / scalingFactor;
magnitude = sqrtf(real * real + imag * imag);
//phase = atan(imag/real)
Serial.print(real);
Serial.print("\t");
Serial.print(imag);
Serial.print("\t");
Serial.println(magnitude);
}
Scalefactor is zero. Division by zero is giving you nan.
tom321:
Don't try to copy advanced code with advanced math without knowing what you do
But yeah, at least you need 'data' to be an array. Of what type and how large is up to you. Try digging deeper in the code you try to copy
tom321
January 4, 2021, 9:59pm
16
without scalingFactor results are the same
/////////////////////
real = (q1 * cosine - q2) ;
imag = (q1 * sine);
///////////////////////
gfvalvo
January 4, 2021, 10:16pm
17
You continue to do this:
float* data;
And then write to data[] like you actually allocated memory for an array. What good to you think will come of writing to memory that doesn't belong to you?
Read This: array - Arduino Reference
Same issue. floatnumsamples is zero. You use it as a divisor so omega is nan and so are anything that use them in a calc.
tom321
January 5, 2021, 12:23am
19
floatnumsamples is zero. = I changed to 20 and have 3 columns of: 0.00 instead of nan.
#include <stdio.h>
#include <math.h>
//#include <getopt.h>
//const float TARGET_FREQUENCY = 1700;
int audioInPin = A0;
int k, i;
//int goertzel_mag(int numSamples, float TARGET_FREQUENCY, int SAMPLING_RATE, float* data);
float omega, sine, cosine, coeff, q0, q1, q2, magnitude, real, imag;
//int q0, q1, q2, omega, sine, cosine, coeff, magnitude, real, imag;
float floatnumSamples =20;
int SAMPLING_RATE = 8900;
float TARGET_FREQUENCY = 0.0;
int numSamples = 0;
int data[96];
float scalingFactor = numSamples / 2.0;
//int q0 = 0;
//int q1 = 0;
//int q2 = 0;
void setup() {
TARGET_FREQUENCY = 1700;
int k;
k = (int) (0.5 + ((floatnumSamples * TARGET_FREQUENCY) / (float)SAMPLING_RATE));
omega = (2.0 * M_PI * k) / floatnumSamples;
sine = sin(omega);
cosine = cos(omega);
coeff = 2.0 * cosine;
Serial.begin(115200);
}
void loop() {
for (i = 0; i < numSamples; i++)
{
//testData[index] = analogRead(audioInPin);
data[i] = analogRead(audioInPin);
q0 = coeff * q1 - q2 + data[i];
q2 = q1;
q1 = q0;
}
// calculate the real and imaginary results
// scaling appropriately
// real = (q1 * cosine - q2) / scalingFactor;
//imag = (q1 * sine) / scalingFactor;
/////////////////////
real = (q1 * cosine - q2) ;
imag = (q1 * sine);
///////////////////////
magnitude = sqrtf(real * real + imag * imag);
//phase = atan(imag/real)
Serial.print(real);
Serial.print("\t");
Serial.print(imag);
Serial.print("\t");
Serial.println(magnitude);
}
gfvalvo
January 5, 2021, 12:33am
20
q0, q1, and q2 all start out with a value of zero. What value do you think they have after this 'for' loop executes?
for (i = 0; i < numSamples; i++)
{
//testData[index] = analogRead(audioInPin);
data[i] = analogRead(audioInPin);
q0 = coeff * q1 - q2 + data[i];
q2 = q1;
q1 = q0;
}
What are the resultant values for real, imag, and magnitude?
