Hi, I’m relatively new to Arduino and I’ve run into a problem.
I’m using capacitive sensing to interact with a wave shield. So if I touch a “button”, a song will play.
To do this I’m using this code:
#include "pins_arduino.h" // Arduino pre-1.0 needs this
#include <FatReader.h>
#include <SdReader.h>
#include <avr/pgmspace.h>
#include "WaveUtil.h"
#include "WaveHC.h"
int capSensePinw1 = 6;
int capSensePinw2 = 7;
int capSensePinw3 = 8;
int capSensePinw4 = 9;
int w = 0;
int w2 = 0;
int w3 = 0;
int w4 = 0;
SdReader card; // This object holds the information for the card
FatVolume vol; // This holds the information for the partition on the card
FatReader root; // This holds the information for the filesystem on the card
FatReader f; // This holds the information for the file we're play
WaveHC wave; // This is the only wave (audio) object, since we will only play one at a time
#define DEBOUNCE 100 // button debouncer
// this handy function will return the number of bytes currently free in RAM, great for debugging!
int freeRam(void)
{
extern int __bss_end;
extern int *__brkval;
int free_memory;
if((int)__brkval == 0) {
free_memory = ((int)&free_memory) - ((int)&__bss_end);
}
else {
free_memory = ((int)&free_memory) - ((int)__brkval);
}
return free_memory;
}
void sdErrorCheck(void)
{
if (!card.errorCode()) return;
putstring("\n\rSD I/O error: ");
Serial.print(card.errorCode(), HEX);
putstring(", ");
Serial.println(card.errorData(), HEX);
while(1);
}
void setup(){
Serial.begin(9600);
putstring_nl("WaveHC with 6 buttons");
putstring("Free RAM: "); // This can help with debugging, running out of RAM is bad
Serial.println(freeRam()); // if this is under 150 bytes it may spell trouble!
// Set the output pins for the DAC control. This pins are defined in the library
pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
// pin13 LED
pinMode(13, OUTPUT);
// enable pull-up resistors on switch pins (analog inputs)
digitalWrite(6, HIGH);
digitalWrite(7, HIGH);
digitalWrite(8, HIGH);
digitalWrite(9, HIGH);
// if (!card.init(true)) { //play with 4 MHz spi if 8MHz isn't working for you
if (!card.init()) { //play with 8 MHz spi (default faster!)
putstring_nl("Card init. failed!"); // Something went wrong, lets print out why
sdErrorCheck();
while(1); // then 'halt' - do nothing!
}
// enable optimize read - some cards may timeout. Disable if you're having problems
card.partialBlockRead(true);
// Now we will look for a FAT partition!
uint8_t part;
for (part = 0; part < 5; part++) { // we have up to 5 slots to look in
if (vol.init(card, part))
break; // we found one, lets bail
}
if (part == 5) { // if we ended up not finding one :(
putstring_nl("No valid FAT partition!");
sdErrorCheck(); // Something went wrong, lets print out why
while(1); // then 'halt' - do nothing!
}
// Lets tell the user about what we found
putstring("Using partition ");
Serial.print(part, DEC);
putstring(", type is FAT");
Serial.println(vol.fatType(),DEC); // FAT16 or FAT32?
// Try to open the root directory
if (!root.openRoot(vol)) {
putstring_nl("Can't open root dir!"); // Something went wrong,
while(1); // then 'halt' - do nothing!
}
// Whew! We got past the tough parts.
putstring_nl("Ready!");
}
void loop(){
int w = readCapacitivePin(capSensePinw1);
int w2 = readCapacitivePin(capSensePinw2);
int w3 = readCapacitivePin(capSensePinw3);
int w4 = readCapacitivePin(capSensePinw4);
if (w > 3){
Serial.print("w1 ");
Serial.print(w);
Serial.println();
playcomplete("w1.WAV");
}
if (w2 > 3){
Serial.print("w2 ");
Serial.print(w2);
Serial.println();
playcomplete("2.WAV");
}
if (w3 > 3){
Serial.print("w3 ");
Serial.print(w3);
Serial.println();
playcomplete("3.WAV");
}
if (w4 > 3){
Serial.print("w4 ");
Serial.print(w4);
Serial.println();
playcomplete("4.WAV");
}
}
uint8_t readCapacitivePin(int pinToMeasure) {
// Variables used to translate from Arduino to AVR pin naming
volatile uint8_t* port;
volatile uint8_t* ddr;
volatile uint8_t* pin;
// Here we translate the input pin number from
// Arduino pin number to the AVR PORT, PIN, DDR,
// and which bit of those registers we care about.
byte bitmask;
port = portOutputRegister(digitalPinToPort(pinToMeasure));
ddr = portModeRegister(digitalPinToPort(pinToMeasure));
bitmask = digitalPinToBitMask(pinToMeasure);
pin = portInputRegister(digitalPinToPort(pinToMeasure));
// Discharge the pin first by setting it low and output
*port &= ~(bitmask);
*ddr |= bitmask;
delay(1);
// Make the pin an input with the internal pull-up on
*ddr &= ~(bitmask);
*port |= bitmask;
// Now see how long the pin to get pulled up
int cycles = 17;
for(int i = 0; i < 16; i++){
if (*pin & bitmask){
cycles = i;
break;
}
}
// Discharge the pin again by setting it low and output
// It's important to leave the pins low if you want to
// be able to touch more than 1 sensor at a time - if
// the sensor is left pulled high, when you touch
// two sensors, your body will transfer the charge between
// sensors.
*port &= ~(bitmask);
*ddr |= bitmask;
return cycles;
}
byte check_switches()
{
static byte previous[6];
static long time[6];
byte reading;
byte pressed;
byte index;
pressed = 0;
for (byte index = 0; index < 6; ++index) {
reading = digitalRead(14 + index);
if (reading == LOW && previous[index] == HIGH && millis() - time[index] > DEBOUNCE)
{
// switch pressed
time[index] = millis();
pressed = index + 1;
break;
}
previous[index] = reading;
}
// return switch number (1 - 6)
return (pressed);
}
// Plays a full file from beginning to end with no pause.
void playcomplete(char *name) {
// call our helper to find and play this name
playfile(name);
while (wave.isplaying) {
// do nothing while its playing
}
// now its done playing
}
void playfile(char *name) {
// see if the wave object is currently doing something
if (wave.isplaying) {// already playing something, so stop it!
wave.stop(); // stop it
}
// look in the root directory and open the file
if (!f.open(root, name)) {
putstring("Couldn't open file "); Serial.print(name); return;
}
// OK read the file and turn it into a wave object
if (!wave.create(f)) {
putstring_nl("Not a valid WAV"); return;
}
// ok time to play! start playback
wave.play();
}
The thing is, I actually don’t want 4 buttons.
I want only one to randomize my 4 songs but I can’t figure out how to do that.