Hello, I have a somewhat basic question and while there is a significant load of information in internet, I cannot quite figure these few things out:
If I want to scale my project down to a single chip, instead of using Atmega328p DIP version, would it be the same as using Atmegs328p 32TQFP version of the chip, the reason why is because I want to build nice board and surface-mount everything to it nicely and 32TQFP version of the chip is smaller. Other than different size and shape and obviouse different pin location, is wiring the same? i.e. quarz and 22pf capacitors is all I need?
Every tutorial I have seen about Atmega328 chip on breadboard showing people powering it with 5v, either directly or via power regulator, however for example arduuino pro mini is 3v device, I want to make 3v device too so I can only power it from 2 AA batteries, is this an easy thing to do, is there a difference in a way how it wired, etc?
3.On Adafruit I saw that some sensors, or LED displays have 5v logic and some 3v logic, again, from my understanding that means that digital pins can read/write signal at 5v or 3v correspondingly. What dictates that, is it as simple as powering chip with 5v gives you 5v login and powering it with 3v gives you 3v logic? Asking because for my project I want to use adafruit nokia display and currently prototype is running on arduino uno via logic converter, but I am wondering if I can simply build my own device with Atmega chip running off 3V source and all logic then will already be 3v so no need to any converter?
Basically, I have a small device that with a push of a few buttons records some data and displays it on Nokia screen. Currently all of that is a prototype on breadboard running on Arduino Uno R3, I want to scale this down to matchbox size, make my own custom board, and so all surface mount solering, I want to go as small as possible, what can you suggest?
Thanks in advance.