Arduino/Atmega328PU wake up with a long button press
Hello there,
I'm working on a new project. One important topic is to save power in standalone Atmega 328PU. The microcontroller is into a deep sleep mode and should only wake up after the button was pressed for over 3 seconds. I wrote the following two codes.
Code:
#define LED_PIN 13
void setup() {
// put your setup code here, to run once:
pinMode(LED_PIN, OUTPUT);
//Save Power by writing all Digital I0 LOW
for(int i=0; i<20; i++){
if(i != 2)//just because the button is hooked up to digital pin 2
pinMode(i, OUTPUT);
}
attachInterrupt(0, digitalInterrupt, FALLING); //interrupt for waking up
}
void loop() {
// put your main code here, to run repeatedly:
digitalWrite(LED_PIN, HIGH);
delay(1000);
digitalWrite(LED_PIN, LOW);
//DISABLE ADC
ADCSRA &= ~(1<<7);
//ENABLE SLEEP
SMCR |= (1<<2); //power down mode
SMCR |= 1; //enable sleep
//BOD DISABLE
MCUCR |=(3 << 5); //set both BODS and BODSE at the same time
MCUCR = (MCUCR & ~(1 << 5)) | (1<< 6); //then set the BODS bit and clear the BODS bit at the same time
__asm__ __volatile__("sleep");
}
void digitalInterrupt(){
//needed for the digital input interrupt
}
Code:
int inPin = 2; // the pin number for input (for me a push button)
int ledPin = 13;
int current; // Current state of the button
// (LOW is pressed b/c i'm using the pullup resistors)
long millis_held; // How long the button was held (milliseconds)
long secs_held; // How long the button was held (seconds)
byte previous = HIGH;
unsigned long firstTime; // how long since the button was first pressed
void setup() {
pinMode(ledPin, OUTPUT);
digitalWrite(inPin, HIGH); // Turn on 20k pullup resistors to simplify switch input
}
void loop() {
current = digitalRead(inPin);
// if the button state changes to pressed, remember the start time
if (current == LOW && previous == HIGH) {
firstTime = millis();
}
millis_held = (millis() - firstTime);
secs_held = millis_held / 1000;
if (current == LOW && previous == LOW) {
// If the button was held for more then 3 seconds blink LED 1 time
if (secs_held >= 3) {
ledblink(1,4000,ledPin);
}
}
previous = current;
}
// Just a simple helper function to blink an led in various patterns
void ledblink(int times, int lengthms, int pinnum){
for (int x=0; x<times;x++) {
digitalWrite(pinnum, HIGH);
delay (lengthms);
digitalWrite(pinnum, LOW);
delay(lengthms);
}
}
The first code is for the deep sleep mode and wakes the Atmega 328PU up after an external interrupt.
The second code is a normal code (without any power saving option) and reads the digital input and sets a timer if the button was pressed. If the timer is over 3 seconds and the button is still pressed something will happen (for example a LED will flash).
So now my question is how to combine them? Is there any way to do that?
I hope somebody can help me :) I'm looking forward to your replies.
Best regards
Maurice W.
