Forum Index > Projects > LED Pegboard and Matrix Projects
 Atmegaxx8 target board--external crystal
 |  Printable Version
By: acidblue (offline) on Tuesday, May 11 2010 @ 07:58 AM PDT (Read 3287 times)  
acidblue

Excuse me if this is a stupid newbie question.
But why are there 3 holes for the external crystal on the board?
Of course that's assuming the footprint marked 'XTL' is for the crystal.

The crystals I bought have only two leads.


Forum Apprentice
Apprentice

Status: offline

Registered: 05/11/10
Posts: 3

Profile Email    
   
By: squall_line (offline) on Tuesday, May 11 2010 @ 10:16 AM PDT  
squall_line

From the product description page in the store:

"Accommodates 3-pin ceramic resonator or crystal oscillator with capacitors. "

From the blog posting of the original card:

"In the lower right is a place to add an optional crystal oscillator with its two capacitors, or a 3-pin ceramic resonator."

HTH!


Forum Mad Scientist
Mad Scientist

Status: offline

Registered: 04/13/10
Posts: 96
Iowa, USA

Profile Email    
   
By: Windell (offline) on Tuesday, May 11 2010 @ 10:23 AM PDT  
Windell

Yep. Some folks (see Adafruit, for example) prefer to use 3-pin ceramic resonators-- effectively a low-precision crystal with the two capacitor built in --on their AVR boards. Our boards fit either.


Windell H. Oskay
drwho(at)evilmadscientist.com
http://www.evilmadscientist.com/

Forum Evil Scientist
Evil Scientist

Status: offline

Registered: 06/15/06
Posts: 1932
Sunnyvale, CA

Profile Email Website  
   
By: acidblue (offline) on Tuesday, May 11 2010 @ 11:04 AM PDT  
acidblue

OK, Thanks.
So I can add my crystal with the 2 caps, just ignore the third, (middle) hole?
Just want to be clear.


Forum Apprentice
Apprentice

Status: offline

Registered: 05/11/10
Posts: 3

Profile Email    
   
By: Windell (offline) on Tuesday, May 11 2010 @ 11:09 AM PDT  
Windell

Yes, that's correct. Big Grin


Windell H. Oskay
drwho(at)evilmadscientist.com
http://www.evilmadscientist.com/

Forum Evil Scientist
Evil Scientist

Status: offline

Registered: 06/15/06
Posts: 1932
Sunnyvale, CA

Profile Email Website  
   
By: acidblue (offline) on Tuesday, May 11 2010 @ 11:19 AM PDT  
acidblue

Fantastic!
Thanks again.


Forum Apprentice
Apprentice

Status: offline

Registered: 05/11/10
Posts: 3

Profile Email    
   



 All times are PDT. The time is now 04:58 PM.
Normal Topic Normal Topic
Locked Topic Locked Topic
Sticky Topic Sticky Topic
New Post New Post
Sticky Topic W/ New Post Sticky Topic W/ New Post
Locked Topic W/ New Post Locked Topic W/ New Post
View Anonymous Posts 
Able to Post 
Filtered HTML Allowed 
Censored Content 

Evil Mad Scientist Forum Archives — Read only!

Please visit our new forums for new discussions.


DIY Hardware for Electronic Art


The Original Egg-Bot Kit


Octolively
Interactive LED kits


Meggy Jr RGB
LED matrix game
development kit.


Business-card sized
AVR target boards


Peggy 2
LED Pegboard kits

My Account






Lost your password?