Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: Becky on February 22, 2009, 10:56:36 AM

Title: Build a $50 robot with ATMEGA328P?
Post by: Becky on February 22, 2009, 10:56:36 AM

Hello,

I would like to build this robot but using the better microcontroller from day 1.  I read something about needing a crystal oscillator and then relevant capacitors to get the full benefits... can anyone explain the extra requirements and difference to building it like this for a beginner?

Thanks very much

Becky

Title: Re: Build a $50 robot with ATMEGA328P?
Post by: Soeren on February 22, 2009, 02:12:37 PM

Hi,

If you use a crystal oscillator, which is a little metal encapsulated device with (usually) 3 or 4 pins, you don't need further capacitors, although it could be decoupled (from the supply pin to ground).
If you use a plain crystal, which is a metal package with 2 pins, you need 2 capacitors.
If you use a ceramic resonator (less precise), you may or may not need further capacitors, as they come in several configurations.

The crystal oscillator is more expensive than a plain crystal, but easier to get working for a beginner.
The crystal oscillator output connects to the µcontrollers OSC_in, while the OSC_out is left unconnected.

Title: Re: Build a $50 robot with ATMEGA328P?
Post by: Admin on March 01, 2009, 07:32:09 AM

Mouser is the only place that sells it so far:
http://mouser.com/search/ProductDetail.aspx?qs=K8BHR703ZXguOQv3sKbWcg%3d%3d

I recommend buying an ATmega8 and going through the tutorial, then swap it out for the ATmega328P when you are ready (using the upgrade microcontroller tutorial). That way if you get stuck, you can use the code from the tutorial. Besides, if you buy both microcontrollers at the same time, it'll only set you back like $2. Definitely worth saving yourself some hair pulling!

As for the crystal, I'm working on a tutorial for that, just haven't motivated myself enough to finish it . . .

Title: Re: Build a $50 robot with ATMEGA328P?
Post by: Becky on March 08, 2009, 10:39:19 AM

Cheers great minds think alike I did order them both anyway (I had to get extra everything so that I could get free delivery from Mouser to Spain).

As for motivation what about "admin, admin he's our man if he can't do it no one can" ... any good...?

Title: Re: Build a $50 robot with ATMEGA328P?
Post by: Pototo on March 08, 2009, 03:41:06 PM

Lazy Admin...LOL

Common we need that tutorial, I have been waiting for years...hahahaha