Hello,
I'm using OpenMusic Labs' fft_adc code to try and do some FFT on my music.
The only change is i've changed serial.write(255) to serial.println(255)
My question is why arent my values changing? I have ADC0 connected to the right pin of my TRRS breakout from sparkfun and then I have ring 2 of the same breakout connected to ground.
My current output looks like the image attached
And your code looks like this:
Oh duh, even after all this time, I forget to post the corresponding code
/*
fft_adc.pde
guest openmusiclabs.com 8.18.12
example sketch for testing the fft library.
it takes in data on ADC0 (Analog0) and processes them
with the fft. the data is sent out over the serial
port at 115.2kb. there is a pure data patch for
visualizing the data.
*/
#define LOG_OUT 1 // use the log output function
#define FFT_N 256 // set to 256 point fft
#include <FFT.h> // include the library
void setup() {
Serial.begin(115200); // use the serial port
TIMSK0 = 0; // turn off timer0 for lower jitter
ADCSRA = 0xe5; // set the adc to free running mode
ADMUX = 0x40; // use adc0
DIDR0 = 0x01; // turn off the digital input for adc0
}
void loop() {
while(1) { // reduces jitter
cli(); // UDRE interrupt slows this way down on arduino1.0
for (int i = 0 ; i < 512 ; i += 2) { // save 256 samples
while(!(ADCSRA & 0x10)); // wait for adc to be ready
ADCSRA = 0xf5; // restart adc
byte m = ADCL; // fetch adc data
byte j = ADCH;
int k = (j << 8) | m; // form into an int
k -= 0x0200; // form into a signed int
k <<= 6; // form into a 16b signed int
fft_input[i] = k; // put real data into even bins
fft_input[i+1] = 0; // set odd bins to 0
}
fft_window(); // window the data for better frequency response
fft_reorder(); // reorder the data before doing the fft
fft_run(); // process the data in the fft
fft_mag_log(); // take the output of the fft
sei();
Serial.println(255); // send a start byte
Serial.write(fft_log_out, 128); // send out the data
}
}
Serial.println(255); // send a start byte
That is NOT what that code does. That code is sending 5 bytes - '2', '5', '5', , and .
The only change is i've changed serial.write(255) to serial.println(255)
Why?
Because I wanted the output on the serial monitor print the different outputs on a new line.
Does that change affect the operation of the code?
Does that change affect the operation of the code?
The output is not meant to be human readable. It is meant to be read, as binary data, by PureData. PureData is expecting a binary value, 255, to mark the start of a packet.
So, yes, it makes a big difference.
Okay, i'll switch it back.
Looks like I gotta figure out how to use pure data!