Hey guys,
which powerful ( most important is the pins number) microcontroller would you advise me for an Arduino uno?
Arduino UNO is based on an ATmega328. 28 pins, of which 18 are usable.
If you need more pins, get an Arduino Mega.
thx ..still got one more question. Does the Arduino uno support the ATxmega* microcontroller ?
"28 pins, of which 18 are usable."
20 are usable - 2 are typically tied up with serial interfacing, but if you are not doing that they are available for other uses.
ATxmega* - check at www.avr-developers.com
If you need some more IO (32) or more RAM (16K, 128K of flash memory), check out '1284 based designs as well.
For example, Reply # 287 on page 20 here
http://arduino.cc/forum/index.php/topic,80483.285.html
"28 pins, of which 18 are usable."
There is pin 0 to pin 18 - that makes 19 input / output pins in all.
which powerful ( most important is the pins number) microcontroller would you advise me for an Arduino uno?
This question makes no sense because there is not a choice, if you choose the Uno you get a Uno.
If you actually just mean Arduino and not Arduino Uno, then as has been said it is a Arduino mega.