Buongiorno.
Ho 4 max72xx,che mi visualizzano lo spettro sonoro (FFT).
Il fatto è che vorrei impostare la luminosità dei display tramite un potenziometro.
Il valore che deve cambiare con il pot è questo:
mx.control(MD_MAX72XX::INTENSITY, 20)
Mentre questo è il codice del programma:
#include <arduinoFFT.h>
#include <MD_MAX72xx.h>
#include <SPI.h>
#define SAMPLES 64 //Must be a power of 2
#define HARDWARE_TYPE MD_MAX72XX::FC16_HW // Set display type so that MD_MAX72xx library treets it properly
#define MAX_DEVICES 4 // Total number display modules
#define CLK_PIN 13 // Clock pin to communicate with display
#define DATA_PIN 11 // Data pin to communicate with display
#define CS_PIN 10 // Control pin to communicate with display
#define xres 32 // Total number of columns in the display, must be <= SAMPLES/2
#define yres 8 // Total number of rows in the display
int MY_ARRAY[] = {128, 128, 192, 224, 240, 248, 252, 254, 255}; // default = standard pattern
int MY_MODE_1[] = {0, 128, 192, 224, 240, 248, 252, 254, 255}; // standard pattern
int MY_MODE_2[] = {0, 128, 64, 32, 16, 8, 4, 2, 1}; // only peak pattern
int MY_MODE_3[] = {0, 128, 192, 160, 144, 136, 132, 130, 129}; // only peak + bottom point
int MY_MODE_4[] = {128, 128, 192, 224, 240, 248, 252, 254, 255}; // one gap in the top , 3rd light onwards 0, 128, 192, 160, 208, 232, 244, 250, 253
int MY_MODE_5[] = {0, 1, 3, 7, 15, 31, 63, 127, 255}; // standard pattern, mirrored vertically
double vReal[SAMPLES];
double vImag[SAMPLES];
char data_avgs[xres];
int yvalue;
int displaycolumn , displayvalue;
int peaks[xres];
const int buttonPin = 5; // the number of the pushbutton pin
int state = HIGH; // the current reading from the input pin
int previousState = LOW; // the previous reading from the input pin
int displaymode = 1;
unsigned long lastDebounceTime = 0; // the last time the output pin was toggled
unsigned long debounceDelay = 50; // the debounce time; increase if the output flickers
MD_MAX72XX mx = MD_MAX72XX(HARDWARE_TYPE, CS_PIN, MAX_DEVICES); // display object
arduinoFFT FFT = arduinoFFT(); // FFT object
void setup() {
ADCSRA = 0b11100101; // set ADC to free running mode and set pre-scalar to 32 (0xe5)
ADMUX = 0b00000000; // use pin A0 and external voltage reference
pinMode(buttonPin, INPUT);
mx.begin(); // initialize display
mx.control(MD_MAX72XX::INTENSITY, 20); //luminosità display
delay(500); // wait to get reference voltage stabilized
}
void loop() {
// ++ Sampling
for (int i = 0; i < SAMPLES; i++)
{
while (!(ADCSRA & 0x10)); // wait for ADC to complete current conversion ie ADIF bit set
ADCSRA = 0b11110101 ; // clear ADIF bit so that ADC can do next operation (0xf5)
int value = ADC - 512 ; // Read from ADC and subtract DC offset caused value
vReal[i] = value / 6; // Copy to bins after compressing
vImag[i] = 0;
}
// -- Sampling
// ++ FFT
FFT.Windowing(vReal, SAMPLES, FFT_WIN_TYP_NUTTALL, FFT_FORWARD);
FFT.Compute(vReal, vImag, SAMPLES, FFT_FORWARD);
FFT.ComplexToMagnitude(vReal, vImag, SAMPLES);
// -- FFT
// ++ re-arrange FFT result to match with no. of columns on display ( xres )
int step = (SAMPLES / 2) / xres;
int c = 0;
for (int i = 0; i < (SAMPLES / 2); i += step)
{
data_avgs[c] = 0;
for (int k = 0 ; k < step ; k++) {
data_avgs[c] = data_avgs[c] + vReal[i + k];
}
data_avgs[c] = data_avgs[c] / step;
c++;
}
// -- re-arrange FFT result to match with no. of columns on display ( xres )
// ++ send to display according measured value
for (int i = 0; i < xres; i++)
{
data_avgs[i] = constrain(data_avgs[i], 0, 80); // set max & min values for buckets
data_avgs[i] = map(data_avgs[i], 0, 80, 0, yres); // remap averaged values to yres
yvalue = data_avgs[i];
peaks[i] = peaks[i] - 1; // decay by one light
if (yvalue > peaks[i])
peaks[i] = yvalue ;
yvalue = peaks[i];
displayvalue = MY_ARRAY[yvalue];
displaycolumn = 31 - i;
mx.setColumn(displaycolumn, displayvalue); // for left to right
}
// -- send to display according measured value
displayModeChange (); // check if button pressed to change display mode
}
void displayModeChange() {
int reading = digitalRead(buttonPin);
if (reading == HIGH && previousState == LOW && millis() - lastDebounceTime > debounceDelay) // works only when pressed
{
switch (displaymode) {
case 1: // move from mode 1 to 2
displaymode = 2;
for (int i = 0 ; i <= 8 ; i++ ) {
MY_ARRAY[i] = MY_MODE_2[i];
}
break;
case 2: // move from mode 2 to 3
displaymode = 3;
for (int i = 0 ; i <= 8 ; i++ ) {
MY_ARRAY[i] = MY_MODE_3[i];
}
break;
case 3: // move from mode 3 to 4
displaymode = 4;
for (int i = 0 ; i <= 8 ; i++ ) {
MY_ARRAY[i] = MY_MODE_4[i];
}
break;
case 4: // move from mode 4 to 5
displaymode = 5;
for (int i = 0 ; i <= 8 ; i++ ) {
MY_ARRAY[i] = MY_MODE_5[i];
}
break;
case 5: // move from mode 5 to 1
displaymode = 1;
for (int i = 0 ; i <= 8 ; i++ ) {
MY_ARRAY[i] = MY_MODE_1[i];
}
break;
}
lastDebounceTime = millis();
}
previousState = reading;
}
