how to attach crystal?

i am making a custom board using atmega328p. i am programming the chip using a arduino uno board which works fine but when i attach the microcontroller to the development board, the delay function doesn't seem to work. I think there is a problem with the oscillator. I have simply connected a crystal at xtal pins. Is this the correct way??

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gadget.iom over 10 years ago +4

Something like this... Google "arduino bare bones"
mcb1 over 10 years ago in reply to clem57 +3

clem57 I see to recall we had a very similar discussion not that long ago. ... The Bare Bones project tend to use a resonator, although they talk about a xtal and neglect to say you need the capcitors…
Robert Peter Oakes over 10 years ago in reply to clem57 +3

I tend to prefer a real xtal and a couple of caps, this gives a much more precise loop time. Either will work without issue and the cost is still measured in Pennies or Cents If your making thousands then…

0 gadget.iom over 10 years ago

What frequency is your crystal?
Have you connected 20/22pF capacitors between the XTAL pins and gnd?
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0 mcb1 over 10 years ago

If you search for schematics there are plenty to show you need 2 x 20pF caps and a resistor.

Mark
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0 gadget.iom over 10 years ago

Something like this...

Google "arduino bare bones"
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0 clem57 over 10 years ago

Please post a schematic or pictures showing what you have. Had to visualize without details.
Thanks,
clem
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0 rishi2628 over 10 years ago in reply to clem57

this is how i have connected the oscillator
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0 rishi2628 over 10 years ago

i was wondering ..........what if i replace the complete circuitry of the crystal oscillator with only a ceramic oscillator..........then will it work??
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0 clem57 over 10 years ago in reply to rishi2628

You need the capacitors as well! This allows the charge up on either side of the crystal....

Add a 16 MHz external clock between pin 9 and 10, and add two 22 pF capacitors running to ground from each of those pins.

Quote from http://www.arduino.cc/en/Main/Standalone

Clem
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0 mcb1 over 10 years ago in reply to clem57

clem57
I see to recall we had a very similar discussion not that long ago. ...

The Bare Bones project tend to use a resonator, although they talk about a xtal and neglect to say you need the capcitors.
http://moderndevice.com/wp-content/uploads/resources/bbb-kit/BBB_RevE_Instructions03.pdf

But seriously can no-one use the google search to find the million or so links for building their own Arduino.?

This has some links that land on the wrong page, but does get you there.
http://playground.arduino.cc/Learning/AtmegaStandalone

Mark
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0 gdstew over 10 years ago in reply to rishi2628

The Arduino Uno uses a ceramic resonator and they usually have the capacitors built into them.
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0 rishi2628 over 10 years ago

suppose i want to select the internal oscillator of the microcontroller...............how will i do it on the arduino ide??..............what setting do i have to change.........or what is the code to select the internal oscillator?
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