I am using Arduino mega to collect some data from a sensor. I am using LCD display to show the Current status of the data acquisition. I am collecting the data as Test 1, test 2............etc. But in between the tests i need some time to set up the test. and also i can not turn off the Arduino as it will overwrite the data once i starts it again. So it takes more time to set up the test than to conduct one. But in between the tests the Arduino is Powered on and as i am using 9V batterries they are not lasting long. After every 70-80 minutes i have to change the batteries.
So i was thinking, can i keep the arduino in sleep mode while i am setting up the test. can i use any interrupts or any other code to switch the modes. How can i use the batteries more efficiently so that they last long?
I am not turning off the LCD as i am using the LCD to display the Menu with the help of which the user is selecting the start of test and end of test. So, i have to show menu as based on this only the user is going to select the further instructions.
Can i switch off the display after waiting for some time if no key is pressed and then again switch it on when i am about to start the new test?
If the LCD has a backlight, its likely to the biggest consumer of power. I read somewhere an arduino with nothing connected to it will run around 9-14 hours on a 9v battery without resorting to sleep. If its eating a battery in 80 minutes, I suspect sleep will make little difference since its your other stuff thats using most of it.