Surface mount and through hole chips

Hello all :)

I have made a project using arduino and now want to experiment with a pcb design of my project. I then want to test it again on a breadboard before going to get a pcb made.

My question is;

On my breadboard I am using ATMEGA328P, but on my pcb I want to use ATMEGA328-an the same chip but just surface mount. Is there something I need to add when using an surface mount? I read in this forum previous that on the ATTINY85 you must use a cap. between the + and - to get it to work.

Anything like this on this chip too?

kjetilhansen: On my breadboard I am using ATMEGA328P, but on my pcb I want to use ATMEGA328-an the same chip but just surface mount.

That's not the same chip. For the same chip you want ATmega328P-AN. ATmega328 and ATmega328P are very similar but they have some different specs and functionalities and also different chip signatures. You can use either with the Arduino IDE but you'll need to install a 3rd party hardware package for the ATmega328 because of the different chip signature, whereas the Arduino IDE already has board definitions that use the ATmega328P (e.g. Uno, Nano, Pro Mini).

kjetilhansen: Hello all :) I read in this forum previous that on the ATTINY85 you must use a cap. between the + and - to get it to work.

Anything like this on this chip too?

You need that no matter which chip package you're using. You might be able to get away without it but you might not. Just use the proper caps and you know your chip will run reliably.

The cap on the Tiny85 power is called a decoupling cap. It is there to filter noise on the power supply lines to smooth the power to the power input to the Tiny85. Most all digital chips need the decoupling caps. The 328 does as well. A 0.1uf cap from Vcc to ground and a 0.1uf cap from AVcc to ground at a minimum. The caps need to be as close to the chip pins as possible.

Ah sorry, I forgot the P. I was planing to use the same chip just surface. But thank you for great answer. Then it should function without any other modifications than cap between the poles. Will also do this for the surface mount :)

I actually made a project earlier with the tiny and some leds pulsing. I did not know about this then, but thankfully it worked without the cap. But I will start adding this to my projects as it reduces the chance of fault.