I'm trying to use atmega328p standalone on 3V. I programmed the chip using the arduino and ran it using 5V and it works perfect with no problems. Once I switched the power from 5V to 3V and 2.8V, it doesn't work. I tried both 16MHz and 10MHz crystal. I read something about fuses but I don't understand anything about that unfortunately
I'm using the arduino as power source only. Also, I have a coin battery thats supposed to be 3V and thats what I'm planning to use on my standalone project. Any advice on how to get the chip to work?
There's a 'brownout detection' fuse that will automatically shut off the microcontroller once the voltage drops under 4.7v, I believe, which you will need to disable.
Also, the coin batteries can only provide a few hundred microamps of current - are you sure that's enough for what you want to do? Otherwise, you would be better off looking for a more useful battery.
The closest lower brown-out level is 2.7 volts. At that voltage, the maximum recommended frequency is 10 MHz (see section 28.3 Speed Grades). While many folks have stated they have had no problems running an AVR processor at 16 MHz / 2.7 volts, doing so does violate the specifications.
Your first step is to decide the clock speed and the brown-out level you will be using. The other choices for the brown-out level are 1.8 volts and disabled.
