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Topic: Building an Arduino on breadboard - Digikey parts (Read 3 times) previous topic - next topic

floresta

#5
Dec 02, 2011, 03:56 am Last Edit: Dec 02, 2011, 04:02 am by floresta Reason: 1
None of these seem to have decoupling (bypass) capacitors on the processor power leads.

Don

xl97

arent those the caps in the corner on the DIY board I made? if not..then I dont know what you mean.

as the 'kit' I believe has them 'under' the chip.. seated in the center of the socket.  (nice little space saver)

kit pic:  [5 total components under the chip, in the socket/center]


floresta

You didn't post that picture before! 

I assumed that the capacitors in the corner of your board are the ~22pF ones for the crystal.  The kit uses resonator which has internal capacitors (hence the need for a third terminal).

Putting the decoupling capacitors under the chip is not only a space saver but it is probably the best location possible since you want those devices as close to the component pins as possible. 

That looks like a very nice kit and your homemade one isn't too shabby either.  Did you include a ground pin between the crystal pins in case you want to substitute a resonator? 


Don

xl97

hi-

yeah I didnt post that one before... I can take a pic of it all put together.. with chip out too.

it 'is' a nice little kit IMHO..  (just needs a vRegulator of some kind)..

I attempted to add one to mine..works fine...  I havent messed with it in a bit.. kinda made it for a buddy who needed to blink some leds but space was odd (a StarWars training remote  prop/mod) shaped.

on my 'attempted' DIY Arduino clonne/pcb..(whatever).. I did 'not' include a ground pin for the option of crystal or resonator

I was looking at tuts on line and 'faking' my way through etching a board.. and designing a PCB..lol..

Using a resonator you still run @ 16mhz?

Thanks

retrolefty

Quote
Using a resonator you still run @ 16mhz?

Yes, if you use a 16Mhz ceramic resonator. Like crystal resonators, ceramic resonators are built for a specific frequency.


http://www.sparkfun.com/search/results?term=resonator&what=products

Lefty

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