Wake up from sleep from pressed button?

Question

#include <avr/sleep.h>
#include <avr/power.h>
//This sketch is a metronome, in which each led pin shows one beat.
const int speaker = 13; //speaker at pin 13
int ts = 6; //highest led pin
int count = 3; //"beat 1 pin"
const int keyPin = 11; //button to change time signature
const int keyPinR = 10; //button to change rhythm
const int keySwitch = 2; //sleep mode/wake up button
//All pins below use a pull-up resistor, so the states are inverted
int buttonState = LOW;
int buttonState2 = LOW;
int switchState = LOW;
int silentState = LOW;
int bpm = 120; //you do not need to know this, 
//it's just a variable for the potentiometer to change the tempo
int rthm = 1; //rhythm 
volatile int pressed = 0;
long silent = p;
void setup()
{
 Serial.begin(9600);
 for(int thisPin = 3;thisPin <= ts;thisPin++)
 {
 pinMode(thisPin,OUTPUT); //initialize thisPin as an output
 pinMode(8, INPUT); //potentialmeter for changing temp 
 //Pin 9 to 11, along with pin 2, are all push buttons with pull-up resistors
 for(int i = 9; i<=11; i++)
 {
 pinMode(i, INPUT);
 digitalWrite(i, HIGH);
 }
 pinMode(2, INPUT);
 digitalWrite(2,HIGH); 
 } 
}
void loop()
{
 turnOn();
}
void turnOn()
{
 buttonState = digitalRead(keyPin);//key for 
 buttonState2 = digitalRead(keyPinR);
 switchState = digitalRead(keySwitch);
 silentState = digitalRead(9);
 //Serial.println(switchState);
 if(switchState==LOW&&pressed==0)
 {
 sleep_enable();
 set_sleep_mode(SLEEP_MODE_PWR_DOWN);
 attachInterrupt(digitalPinToInterrupt(0), interrupt, LOW);
 sleep_cpu();
 //Serial.println(switchState); 
 } 
 else {
 //The beat starts at pin 3, runs in consecutive pins, 
 //and ends at pin 8 at maximum
 if(buttonState==LOW)
 { //changing time signature - up to 5 beats
 ts++; 
 if(ts==8)
 {
 ts = 3;
 //8 - 3 = 5 beats max
 } 
 }
 if(buttonState2==LOW)
 { //changing rhythm - quarter note to eighth, then 
 //triplets and sixteenths, back to quarter notes
 rthm++; 
 if(rthm==5)
 rthm = 1; 
 }
 if(silentState==LOW){//if silent key pressed, go to silence (only LED's showing) 
 silent++;
 }
 //The RUN code 
 for(int thisPin = 3;thisPin <= ts;thisPin++)
 //LED's blinking beats (thisPin - LED pin (beat number + 2))
 { 
 for(int r = 1; r<=rthm; r++)
 {//nested loop for the rhythm 
 bpm = pulseIn(8, HIGH);//pin 8 - tempo potentialmeter
 digitalWrite(thisPin,HIGH);//each LED blinks
 pinMode(13,OUTPUT); //pin 13 - speaker 
 if(silent%2==0)//Press once, tone, press again, no tone
 noTone(13);
 else
 if(count == 3&&r==1). //first beat is higher
 tone(13,4400,80);
 else if(r==1). //downbeats slightly lower
 tone(13,2500,80);
 else
 tone(13,2200,60); //off beats even lower
 delay((bpm-52)/rthm); 
 digitalWrite(thisPin,LOW); //turn each off as we proceed to the next beat (LED)
 pinMode(13,INPUT); //speaker input 
} 
count++; //beat++
if(count >ts){//go back to count
count = 3;
} 
 }
 }
 }
void noSound()//silence the speaker
{
 noTone(13);
}
void interrupt()//this is where the sleep interrupt starts - //how can i press it to wake up???
{
 sleep_disable(); 
 detachInterrupt(0);
 if(switchState==HIGH){ 
 pressed = 1;
 Serial.println(switchState);
 turnOn(); //go back to the main functional method (?????)
 }
 }

Once the keySwitch button is pressed (pin 2), the arduino goes to sleep; however, the only way to turn it on is by resetting everything. How can I just wake up the Arduino, keeping every state as before the sleep interrupt?

Answer 1

attachInterrupt(digitalPinToInterrupt(0), interrupt, LOW);

should be either

attachInterrupt(0, interrupt, LOW);

or

attachInterrupt(digitalPinToInterrupt(2), interrupt, LOW);

As pin 0 is not an interrupt pin. Also the button is connected to pin 2, not pin 0. digitalPinToInterrupt(0) would actually return -1.

• Chris Stratton: It would be a lot more useful if you explained your apparent theory that the wrong pin is being monitored rather than just proposing an unexplained change to the code.
• Gerben: @ChrisStratton thanks for the suggestion. MikeZhou; you are welcome.