Attiny85 project power consumption !

Hello guys!

I hooked up an HC-05 which is a Bluetooth module with an Attiny85 to control a 220v device using a 5V relay, i want to power it using 3 AA batteries so i really want to use the sleeping mode of the attiny85.

Since i’m new, i really don’t know how to do that, and didn’t find much on the internet, i found that you can use the watch dog timer, but i really don’t know anything about it, so if you could help me out, it would amazing!
Thanks!

here’s my code so far:

#include <SoftwareSerial.h>

int relay = 3; // pin 2 of attiny85

char value;

int RX = 0, TX = 1;

SoftwareSerial mySerial(RX, TX);

void setup()

{
pinMode(relay,OUTPUT);

mySerial.begin(9600);

}
void loop()
{
if(mySerial.available())
{
value = mySerial.read();

if(value == '1')

{
digitalWrite(relay, HIGH);

}
else if (value == '0')
{

digitalWrite(relay, LOW);
}
}
}

Please follow the advice on posting a programming question given in Read this before posting a programming question

In particular note the advice to Auto format code in the IDE and to use code tags when posting code here

OK, that code is virtually unreadable!

Get with the project! You need to go and read the forum instructions so that you can go back and modify your original post (not re-post it) - using the “More → Modify” option below the right hand corner of your post - to mark up your code as such using the “</>” icon in the posting window. Just highlight each section of code (or output if you need to post that) from the IDE and click the icon.

In fact, the IDE itself has a “copy for forum” link to put these markings on a highlighted block for you so you then just paste it here in a posting window. But even before doing that, don’t forget to use the “Auto-Format” (Ctrl-T) option first to make it easy to read. While you were lucky so far, If you do not post it as “code” it can easily be quite garbled and is always more difficult to read due to the font.

It is inappropriate to attach it as a “.ino” file unless it is clearly too long to include in the post proper. People can usually see the mistakes directly and do not want to have to actually load it in their own IDE. And even that would also assume they are using a PC and have the IDE running on that PC.

Also tidy up your blank space. Do use blank lines, but only single blanks between complete functional blocks.

Thank you for the advice, i did the modification, and I hope it looks better now!

If the code compiled and the advice was followed I would not see this:

digitalWrite(relay, LOW);
}
}
}

Study this excellent tutorial on sleep modes and power saving.

Hint: as a beginner, you have chosen a complex project. We strongly suggest to work through the tutorials that come with the Arduino IDE, or are on line, before starting something like this. If you don’t, expect endless frustration.

Thank you! will follow that tutorial !