Warning: This is my first post and I am not a native english speaker... writer... whatever. You have been warned.
I did searched for this first, and I was surprised by the lack of info in this regard.
Putting it simple:
I am making a project using the atmega328p, but no one seems to have asked this before:
Do I have to feed 5vcc and GND in each port in the IC (DIP-28)?
Can´t I just program the IC in a Arduino Uno board, remove the IC, solder it to the PCB, then buy a new IC, burn bootloader, program it on the board, remove the IC, solder... cicle?
Max analog voltage input?
What happens if I use no crystal oscillator in the PCB (with a IC programmed in a Arduino Uno board)?
Can I just solder to nothing the Reset pin (given I wont use it in my design)?
I think that's all. Thanks.
The attachment is a part of the board i'm workig in. It's the only section connected to the Atmega, the full design is too large for a screenshot.
Do I have to feed 5vcc and GND in each port in the IC (DIP-28)?
Yes, each power pin needs connecting. You also need a 0.1uF ceramic capacitor on each 5V pin to ground.
Can´t I just program the IC in a Arduino Uno board, remove the IC, solder it to the PCB, then buy a new IC, burn bootloader, program it on the board, remove the IC, solder... cicle?
yes you can.
Max analog voltage input?
The same as the voltage you apply to the 5V pins, this is normally 5V.
No crystal and it will not work unless you set the fuse pins for a free running 8MHz oscillator.
No the reset pin needs connecting to 5V through a 10K resistor.
You need a resistor in each base in those transistors.
Here's a few links I saved when I was working on the same thing a while back:
https://mycontraption.com/embedding-an-arduino-on-prototyping-board/
-Laggy
Zillions of thanks to all of you. I knew I could trust the community.
-Carlos
Grumpy_Mike:
You need a resistor in each base in those transistors.
Since he has the transistors configured as common-collector, a base resistor isn't absolutely essential, except for on PQ1 if it's connected as common-emitter.
@BURNBLADE , you're aware that in that configuration, the highest voltage you can get at the emitters of transistors Q1 to Q6 is about 4.4V? It's more usual to connect them in common-emitter configuration, unless there's a good reason not to do so. We can't see enough of your circuit to really know what's going on. (You probably know what you're doing in this regard, but I just thought I'd better mention it. Many people don't know what they're doing. 
)
You don't show how PQ1 connects to external circuitry, but if it's also connected as common-collector, only about 3.8V is available at the emitter when the transistor is 'on', regardless of the supply voltage connected to the collector. If it's connected as common-emitter, a base resistor is necessary, as mentioned above.
Just one other point - when drawing NPN transistors, the convention is to have the emitter at the bottom, not the top.
Out of interest, what software did you use to draw the schematic?
Hi,
You need to post the complete sheet of your circuit, i can only see the 328 and some transistors,where have you got your gnd and 5V connected.
Tom... 
@OldSteve: no, I wasn't aware of that. I want to control 5vcc using 5vcc (for protection, I really don't want to use directrly the IC's output to power up relay coils).
Transistors are that way because i'm lazy and just used "mirror". I used DipTrace.
@TomGeorge: I feed the 328 with a 7805. It's a big drop: 24vcc to 5vcc. It gets quite hot rapidly, but not to the point of melting down.
Any advice will be apprecciated.
-Burnblade
Try a switching regulator with 7805 pinout
What am I missig?
The image is an example of how I think transistors work.
Hi,
You will need bypass capacitors around the 328 and they are essential around the LM7805.
Please check the datasheet on the 7805 please.
The resolution of your circuit diagrams is to low to get all the information needed from it.
This diagram.
Is correct on how to drive a relay with a transisitor, but your diagram is to low resolution to tell pin numbers and transistor orientation.
Tom...
