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/*
\\DS1821\Datas\ELECTRONIQUE\TEENSY\Essais pgm\sketch_FIR_005\sketch_FIR_005.ino
*/
#include <Audio.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <SerialFlash.h>
#include <Bounce.h>
#include <filter_fir.h>
//This section has been copied from the Teensy FIR example
// If this pin is grounded the FIR filter is turned off
// which just passes the audio sraight through
// Don't use any of the pins listed above
#define PASSTHRU_PIN 1 //donc si je comprends bien il faut mettre la pin 1 à +3.3V ??
// If this pin goes low the next FIR filter in the list
// is switched in.
#define FILTER_PIN 0 //if I understand correctly, the input of the Filter is pin 0
/*
These lines are followed by two "debounce" instrutions that are unknown to me,
// seem to manage the buttons, that I don't use in my project, so I remove the "bounce" lines
*/
// GUItool: begin automatically generated code
AsyncAudioInputSPDIF3 spdif_async1; //xy=145.3333282470703,121.33333587646484
AudioFilterFIR fir1; //xy=353.25,121.25
AudioOutputI2S i2s1; //xy=569.25,126.25
AudioConnection patchCord1(spdif_async1, 0, fir1, 0);
AudioConnection patchCord2(fir1, 0, i2s1, 0);
AudioControlSGTL5000 sgtl5000_1; //xy=360.25,265.25
// GUItool: end automatically generated code
//LPF Coefficients provided by T-Filter
// I got only 5 coefficients, that is not enough, but I don't know why !?!
const short length = 57; // définition de la longueur du filtre, i.e le nombre de coefficients
// Liste des 57 coefficients bruts donnés par lesite arc.id.au de calcul des fltres
float Coeffs_Bruts[] = { -0.000220, 0.000395, -0.000589, 0.000753, -0.000817, 0.000696, -0.000308,
-0.000416, 0.001510, -0.002950, 0.004644, -0.006416, 0.008012, -0.009109, 0.009343, -0.008340,
0.005765, -0.001367, -0.004979, 0.013234, -0.023175, 0.034397, -0.046329, 0.058275, -0.069471,
0.079153, -0.086631, 0.091355, 0.907029, 0.091355, -0.086631, 0.079153, -0.069471, 0.058275,
-0.046329, 0.034397, -0.023175, 0.013234, -0.004979, -0.001367, 0.005765, -0.008340, 0.009343,
-0.009109, 0.008012, -0.006416, 0.004644, -0.002950, 0.001510, -0.000416, -0.000308, 0.000696,
-0.000817, 0.000753, -0.000589, 0.000395, -0.000220};
// The declaration below seems similar to the "struct" declaration used in the Teensy FIR Filter example
// but the "const" approach has been said to be more optimized than the éstruct" approach
const short fir1_Coeffs[57]; // définition du tableau de constantes que l'on va calculer
// à partir de la liste "Coeffs_Bruts" du dessus
//const int myInput = AUDIO_INPUT_MIC; // remove from the Teensy FIR example
const int myInput = AUDIO_INPUT_LINEIN; // because my correct input is not MIC
// d'autres exemples utilisent myInput = AUDIO_INPUT_LINEIN;
// avec un diagramme AudioDesignTool dans le domaine digital aussi
// par ex le prog "Invert Phase Audio Signal"
unsigned long last_time = millis(); // copied from the Teensy FIR example
void setup()
{
Serial.begin(9600); //copied from the Teensy FIR Filter example
delay(300); //copied from the Teensy FIR Filter example
//transfère les Coeffs_Bruts dans le tableau LPF_Coeffs, sous forme "short"
for (int i=1 ; i<=length ; i++) {
fir1_Coeffs[i] == (short) (32768 * Coeffs_Bruts[i]);
/*
if (i=length){
Serial.println("Tableau fir1_Coeffs initialisé");
Serial.println("Length= ", length);
}
*/
} //fin du remplissage du tableau fir1_Coeffs
pinMode(PASSTHRU_PIN, INPUT_PULLUP); //probably activates the Pull-Up resistor because PASSTHRU_PIN is defined as an input
pinMode(FILTER_PIN, INPUT_PULLUP); //probably activates the Pull-Up resistor because FILTER_PIN is defined as an input
//setup the audio shield
AudioNoInterrupts(); // added to the Teensy FIR example: recommended in the video
// what are the benefit ???
// mentionned at the very beginning
AudioMemory(16); /*
The numberBlocks input specifies how much memory to reserve for audio data.
Each block holds 128 audio samples, or approx 2.9 ms of sound.
*/
// Enable the audio shield. select input. and enable output
sgtl5000_1.enable(); //added: was it missing in the Teensy example
//sgtl5000_1.InputSelect(myInput);
/*
dois-je mettre spdif_async1 ou bien LINEIN comme dans la video ???
Je pense spdif_async1 puisque c'est le nom donné à AsyncAudioInputSPDIF3
qui remplace le AudioInputI2S de la video
Pas sûr car le pgm "Invert Phase Audio Signal" utilise bien
AUDIO_INPUT_LINEIN, donc je laisse myInput défini à
AUDIO_INPUT_LINEIN
*/
sgtl5000_1.lineInLevel(5);
//sgtl5000_1.unmuteheadphone();
sgtl5000_1.volume(0.5); // I have a doubt about the parameter: is it correct ???
fir1.begin(fir1_Coeffs, 5); //initialize the fir filter 'fir1" declared before
AudioInterrupts(); //as recommended in the video
// Warn on the Serial Monitor if the passthru pin is grounded
if(!digitalRead(PASSTHRU_PIN)) {
Serial.print("PASSTHRU_PIN (");
Serial.print(PASSTHRU_PIN);
Serial.println(") is grounded");
}
// Warn if the filter pin is grounded: what for ??
//it is supposed to be the filter input, isn't it ?
if(!digitalRead(FILTER_PIN)) {
Serial.print("FILTER_PIN (");
Serial.print(FILTER_PIN);
Serial.println(") is grounded");
}
//ADDED to the Teensy FIR example (as recommended by the video)
fir1.begin(fir1_Coeffs, 5); //Iniitialize the LPF filter as recommended by the AudioDesignTool
Serial.print("fir1 Filter: begin done"); // displays on the Serial Monitor
Serial.println("setup done");
}
void loop() //la video ne dit pas quoi faire dans cette boucle loop,
//et l'exemple de Teensy pas grand chose !
{
// print information about resource usage
// Proc = 18 (18), Mem = 4 (5)
if (millis() - last_time >= 2500) {
Serial.print("Proc = ");
Serial.print(AudioProcessorUsage());
Serial.print(" (");
Serial.print(AudioProcessorUsageMax());
Serial.print("), Mem = ");
Serial.print(AudioMemoryUsage());
Serial.print(" (");
Serial.print(AudioMemoryUsageMax());
Serial.println(")");
last_time = millis();
}
} |
